Teardown and Inspection of Briggs and Stratton 12.5 HP I/C Flathead Engine

BRIEF INSPECTION of a Briggs 12.5. This engine overheated. Needs alot of work, gonna be put off for a while, needs bored out and resleeved and new valve guide bushings pressed in. Thanks for watching.

[@jamesgilman6313]

wow! thank you for showing this. I haven't seen a deep engine look like this. It was good to see what can and does happen to engines.

[@fnaguitarplayer9]

Your welcome! I also have several other complete rebuild videos too. Thanks for Watching!!!

[@williamtucker3558]

Really good video! Love to see them tore down and rebuilt.

[@ChuckX182]

So glad I found your video. Mine just threw a rod yesterday and I’m getting ready to tear it down.

[@4albo20]

Nice video. I like how you keep it simple.

[@delavalmilker]

I got an engine exactly like this one on my MTD riding lawn mower, that my brother got in 1995. Has given me years of service and the mower is still in great shape. However the engine needs a rebuild. And the tragic thing is that some critical parts like the exhaust valve and cylinder head are no longer available. It is sad that our society has become so "throw-away" and people just buy new and no longer fix things as our grandparents did. Sad that these parts become scarce after a few years.

[@danielmeyer4515]

If it still runs then u won't need new valves just relap them. And u will find these parts used on the internet somewhere like marketplace Facebook.

[@hoangvansu2]

I looked around for intake valves and exhaust valves but couldn't find them for sale,I've grinded too deep, now the engine won't start, I don't know what to do,Can someone help me?

[@daryldecamp6295]

Same motor on my m.t.d. Bought my rider new in 95, and it’s still in use today. I have a 13 hp. John Deere that I’m going to rebuild over the winter. Thanks for video

[@fnaguitarplayer9]

Great reliable engines! Your welcome, Thanks for Watching!!!

[@loniedavis1167]

THANKS FOR THE VIDEO ! WORKING ON A 14.5 H.P. FLAT HEAD ! GAVE ME A LOT OF GOOD INFORMATION !

[@fnaguitarplayer9]

+LONIE DAVIS Your welcome, glad to help out! Thanks for Watching!!!

[@n4120p]

Good video you do know engines ,you know exactly the key parts to look on !!

[@fnaguitarplayer9]

Thanks! I was disappointed in this engine, I was hoping to rebuild it. I still have all the parts. Thanks for watching!!!

[@JodBronson]

That is an I/C Briggs and Stratton..., can not kill those easily !!! Best Engine ever made as far as I can see. That Engine I/C Series was the Best Line that B&S came out with..., my opinion!

[@fnaguitarplayer9]

I agree they are some of if not the best they put out, built to last, not replace like new ones! Thanks for watching!

[@enemyhero]

I like the vanguard single pistons

[@fnaguitarplayer9]

thanks. heard that, great motors, hope you can get it. thanks for watching!!!

[@Ethan-ck6iz]

My 12hp briggs flathead on my mower sounds just like this. Was able to adjust the valves and get it by this year. Might rebuild this winter if it isn't that bad on the inside but after watching, I don't have high hopes

[@fnaguitarplayer9]

my main torque wrench (3/8 drive) is craftsman, i got it at a yardsale for 25 bucks! a new one is less than 100. I do have a 1/2 drive that i bought from harbor freight for 10 bucks, i use it for torquing flywheels and anything big, its not the best but it gets the job done, what i mean is, i don't know how long it would hold up. you can get a decent one at just about any auto parts store for not to much, that should hold up good. thanks for watching!!!

[@fnaguitarplayer9]

thanks for that, i'll reply back on his comment. Thanks for watching!!!

[@fnaguitarplayer9]

what usually happens is the valve guides wear out and oil seeps past the valve stems while its running, on OHV motors they usually only smoke when you first start them up, when the guides are worn, some have seals like on a car engine, that can be replaced but on these older flathead / L head engines, you have to get new valve guides pressed in. Thanks for the sub and thanks for watching!!!

[@postal2199]

same engine as mine, useful, educational, thank you!

[@fnaguitarplayer9]

@MrTpengineer i hear ya. i'd hate to have to pull start one of these, probably wouldn't be to fun haha might take a little work, but i'm sure you can get it going. thanks for watching!

[@fnaguitarplayer9]

Thanks! I've tipped several motors over and never had no problems except the occasional oil burning if you tip it over the wrong way, it should not have damaged it at all, have you tried starting it back up since? Its possible that it may have flooded the engine and made it choke out. thanks for watching!

[@fnaguitarplayer9]

yes they are identical engines just a different sticker! now the only possible difference is the cylinder bore, on some power builts the bore is aluminum but on all I/C's they are cast iron sleeved, just check that first, because the rings will be different in a aluminum (kool bore) engine. on briggs motors look at the first 1-2 digits of the model number, on 12 and 12.5's (same again) they are model 28 which means 28 cubic inch. thanks for watching!

[@fnaguitarplayer9]

They are a fun hobby! Thanks for Watching!!!

[@fnaguitarplayer9]

glad you like them!

[@fnaguitarplayer9]

i've been thinking about it! haha thanks for watching!!!

[@fnaguitarplayer9]

Great engines, until this happens haha your welcome, thanks for watching!!!

[@fnaguitarplayer9]

You can still buy valves for these motors, look on tulsa engine warehouse, it won't be briggs brand but a good aftermarket brand. You can usually get buy with re-using the same head, some will have them milled down and a new gasket. I do agree with you, it used to be R&R remove and replace parts now its TO&BN throw out and buy new equipment haha I hate that. Its really not fair either. Thanks for Watching!!!

[@fnaguitarplayer9]

Appreciate it! I have another video (4 part) on tearing a 12.5 horse down and completely rebuilding it, i go into alot of detail on it compared to this one! thanks for watching!!!

[@fnaguitarplayer9]

it burnt more oil than it did gas! i ran it for like 20 minutes that day and it burnt almost a quart of oil! i still got the engine. thanks for watching!!!

[@MattsRageFitGarage]

It's amazing that thing still ran haha that thing's in pretty sad shape it had a good sound to it though minus the knock LOL

[@dansmith4654]

Mine is very same engine new in 96, and still mowing a acre of ground with it. No oil use and still runs super. Wish my truck would last this long

[@fnaguitarplayer9]

I hear ya, they are great engines. Thanks for Watching!!!

[@fnaguitarplayer9]

@bigborekit12 i figure so. how did set a vertical shaft engine on a go kart? did you have a gear box or something? thanks for watching

[@LawnMowersThingsThatMakeNoise]

The head and piston crown + valves look clean for a smoker :-) looks good so far :-) i love these vidoes by the way +Fnaguitarplayer9

[@fnaguitarplayer9]

we actually had it apart a year before this video was made, we had to reseat the valves or something and we cleaned the carbon out while it was apart. I hear ya! Thanks for Watching!!!

[@fnaguitarplayer9]

thanks! i did do a more in depth video of teardown, rebuild and reassembly, on a 12.5 horse power built, its a 4 part series, look through my videos to find it. i might be rebuilding this engine this summer, not for sure though. thanks for watching!!!

[@fnaguitarplayer9]

i'm not sure on the type and code, but the model on this is a 281707, if i remember right. thanks for watching!!!

[@David-yy7lb]

I have a 97 Yard Machine 12.5 hp riding mower that i use to cut my 2 acres every year the motor doesn't smoke or knock runs like a top til this day👍🏿

[@tankeryankercruz7795]

Good video

[@fnaguitarplayer9]

Thanks for Watching!!!

[@fnaguitarplayer9]

this was my old camera a HP V5040u (1080p). My new camera is a JVC Everio GZ HM30BU, which i highly recommend! its a got a great zoom and better sound quality than the HP i used to use! thanks for watching!!!

[@directorski]

Thanks for the reply. Theres no compression, I may have damaged the rings from an ingest of oil. Maybe not worth the expense of getting it repaired.

[@directorski]

Hi. Great videos BTW. I have this engine in a Hayter 13/30 ride on mower. I recently tipped it on it's side to change a belt, went to start it, made a funny noise and stopped. Do you think I may have damaged the rings? many thanks.

[@fnaguitarplayer9]

@V8Mike93 yeah. i'm not sure what i'm gonna do yet, i'm take a closer look at, if its just that one crack i might fix it, then build it as a stock motor, but who knows haha i couldn't do that to a engine, if it was a tecumseh i'd do it in a heart beat haha thanks for watching

[@fnaguitarplayer9]

@30GB i probably will, but i've looked it over real good and its just the one crack in the valve spring area, so i don't know hahaha thanks for watching!

[@unclefreddie7562]

great video...thanks to you, i might actually take mine apart....i think i broke the connecting rod. when i try to start it, the flywheel just spins and that's it, any suggestions?

[@andriesmatthijs1215]

Hello, I have the same problem. Do I just need to remove the scratches with a honing machine? And how do I know to buy oversize rings?

[@fnaguitarplayer9]

It may have blown a head gasket, did it smoke any before it died? If it the headgasket your only looking at about 10 bucks (plus shipping of course) so its not a huge repair, but make sure thats what is first, just like checking a gas pipe or a tire for leaks use soap and water around it and see if it bubbles when you crank it over.

[@fnaguitarplayer9]

yepp. i decided to not rebuild it (at least for now) its sitting in the back for decoration haha thanks for watching!!!

[@ANDERSONEXPRESS7]

I really wish i had your knowledge

[@markjohnson7508]

I see the butterfly screw came off carb at some point. Dented er up pretty good.

[@fnaguitarplayer9]

@Mrengineerwannabe1 to be honest with you, i've never done it myself. they have to be drilled out (on a milling machine) and a new one pressed in. similar process to resleeving a cylinder. i'm not sure if there is any videos of it online or not, i do have a couple of 5 horse engines, and the one in this video that needs new guides. Thanks for watching!

[@fnaguitarplayer9]

Yeah, i never did use it for anything, its still sitting in the back for looks haha thanks for watching!!!

[@awongutume]

Hello, would a used replacement Briggs, 12 HP 282707 piston and block crankcase housing work in a 12 HP I/C 283707 engine reusing other parts from disassembly? Thank you!

[@McCuneWindandSolar]

I see I commented before here I just got a 12.5 HP Briggs just like the one you are rebuilding I will be using your videos to rebuild it. I only gave 7 bucks for it at and auction it runs. but it leaks oil like crazy from the oil pan gasket, and smokes like crazy, carb needs rebuilt because it burns to lean. when I got it it wouldn't start so I pull he head off and found a lot of carbon build up a round the exhaust and the fuel inlet valve look like it got to hot but looked really crusty. so I just clean them up some and put the head back on and it fired up and it ran good other than the smoking, witch caused it to stop working again because of the oil. I plan on doing a rebuild on it and use it to replace the 10 hp briggs on the mower I have it on there now and used it to get my yard under control LOL. it dose not nock so thats good. now to get to work on it and yes I will be using your videos to rebuild it LOL

[@fnaguitarplayer9]

McCuneWindandSolar I hear ya! Even for parts thats a good deal, can't beat that! yeah a motor that doesn't knock is always worth rebuilding. Probably all you need is gaskets and rings, the valve guides are probably worn but is hard to do your self without proper tools, i don't even have that. This motor in the video smokes just a tad do to the guides being worn, but mainly just when you start it with choke (vacuum pulls oil past the guides). Good luck on your rebuild! Thanks for Watching!

[@HowardJohnstone]

I just rebuilt this exact model since the shaft shattered. (NO other damage, cracks etc!)However, its impossible to start, backfires heavily. Grinded the intake valve slightly inorder to reduce backfire into carb. Shaft gear key, timing marks aligned, no sheard fly key,new magneto, strong spark, checked piston, valves & fly -positions, all o.k in the cycle.I´am totally bewildered, Engine fires in totally wrong positions, different all the time.

[@fnaguitarplayer9]

I hear ya. I'm not sure right off hand what may have caused it. The only time i had one do that was when i put the wrong camshaft in it (flathead engine, i put a OHV cam in by mistake, timing was 100% backwards!) is there any chance you may have mixed the camshaft with another engine? if not, then I'd suggest checking the carburetor out, alot of times when a engine is rebuilt, the carburetor will act up since there is more compression, and also more vacuum. Let me know if this helps, if not I'll try and think of something else! Thanks for Watching!!!

[@fnaguitarplayer9]

you would ask that haha I have no clue right off hand i'm not at my garage so i can't look at it, i remember the model it was 281707. sorry about that, if you look though my videos i rebuilt a 12 horse (same thing as a 12.5), and i show the model type and code on it I believe, only difference is the cover was black haha its a 4 part video. sorry about that! thanks for watching!!!

[@fnaguitarplayer9]

@MrTpengineer yeah probably a good idea, may not hurt to spray some wd40 or PB in the cylinder. just depends. i love doing old starts, batteries and starters don't though haha

[@VintageOutboardMan]

Which camera were you using for this video?

[@MrVideoman44]

what brand of torque wrench do you use? I don't have one I want to buy one but don't want junk, but don't want to brake the bank either.

[@pimpss88]

No problem.Enjoy the videos

[@ANDERSONEXPRESS7]

What do u think of the opposed twin briggs engines

[@DonovanBryant92]

got one of these from a local junkyard for only 5 bucks engine had a cracked intake manifold and a seized crankshaft after getting it home i took the engine apart to find water in the engine and a little bit of rust went back next day and purchased a 13.5 Flathead that had been set on fire somehow took it apart and was able to put everything on the 12.5 should be running hopefully soon

[@fnaguitarplayer9]

I hear ya! Thats a good deal, parts alone are worth more than that. I've saved many of them from going to junk! good luck on it! Thanks for Watching!!!

[@JodBronson]

That is an I/C Briggs and Stratton..., can not kill those easily !!! Best Engine ever made as far as I can see. That Engine I/C Series was the Best Line that B&S came out with..., my opinion!

[@JodBronson]

+Donovan Bryant - Yup, I agree with you 100% !!! Look at the video I made recently on my MTD. It sat out for 6+ Years.... Rain, Snow, Sun.... ETC... It starts right up with just a few things I did to it. kzbin.info/www/bejne/inKpd6SKms2Yjck

[@larrykeesee1442]

IF U BORE THE ENGINE OUT..WHERE DO U BUY THE SLEEVE FOR IT?? RETIRED LARRY IN INDIANAPOLIS..

[@fnaguitarplayer9]

sorry i didn't reply to this, i just seen that someone spammed your comment for some reason. thanks, i try to keep stuff as simple as possible. thanks for watching!!!

[@bozscaggzz7475]

Does it need to be bored out?

[@allanhughes7859]

No don't junk it and save the money as some folk think. Whats wrong with the word repair these days "and save money" and get to know your machine ?? I tend to think its the new generation but not sure??? If it breaks just get another ?????? NO FIX THE DARN THING IF YA CAN !!!!!!!!! A new ride on or even a new push mower cost loads and loads of Dollars these days and sadly the new stuff ain't made half as well Thanks for taking the time for the up load I now know how my 12.5 Briggs is put together Cheers !!!!!!!!!!

[@fnaguitarplayer9]

Thats how i feel, i always try to save something. If i throw something out it is complete unrepairable junk haha I do have some blocks and stuff that need machine work to use but still hang on to them. Thanks for Watching!!!

[@fnaguitarplayer9]

@Dillon1791 hahahahahha i've done starting using parts off from it, i don't really want to destroy it, everything except the block and piston is fine in this engine. I don't care for tecumseh (i call them tejunkseh haha) much at all haha thanks for watching

[@smartmissymrs.nepomuceno8423]

how may times we need to use choke specialy in the morning its hard to start .. thanks.. 16hp briggs nd straton

[@gonesideways6621]

How did you get flywheel off ?

[@fnaguitarplayer9]

@farmingpower1066 yeah might scrap it. might decide to hang on to it till i get some extra money and get it bored and resleeved, but still afraid of it because of the crack in the valve area. thanks for watching!

[@fnaguitarplayer9]

If its really cold out you will have to choke for the first 4-5 minutes, in summer weather they usually only have to be choke for less than half a minute. thanks for watching!

[@The4nk8er]

hay are the gutts out of the 12.5 powerbuilt and 12.5 I/C interchaingeable they look the same but lol

[@1899lpv]

Wow.... Now that an engine playing its last tune. Chances are that it will re-appear in another video (hopefully).

[@McCuneWindandSolar]

I'm in the process of rebuilding a 10hp Briggs model 254707 I need to bet a set of valve spring pliers so I can take the valves out. I have one all tore down, that I'm rebuilding, it needs to rings and the cylinder needs redone. piston and cranks all in good shape. and with this rebuild I want to get ride of that balancer that's what broke on my last motor. now to get it all cleaned up and all the old paint off. to repaint but not paint the piston part with the fins to make a nice new motor. ordered all the rebuild parts. cant wait to get the thing up and running again.

[@fnaguitarplayer9]

McCuneWindandSolar I hear ya! I have a 10 horse model 23 that i will probably be rebuilding next year, on it all the gaskets are leaking so i figure i'd just rebuild while its down, since you can see a chug of smoke every now and then from it. good luck on your project! Thanks for Watching!!!

[@bleachedpc]

nice vid will buy one were i em if the deal works out

[@fabiotedesco2902]

Good morning, I am writing to you from Italy, to find out if you have spare parts for the 12.5 hp briggs stratton engine model 289707 type 0121-01. greetings from Italy

[@Reno7721]

I have the same motor; had the mower since ‘94 & never had a problem til now. I went to start it for the 2019 season. The motor cranks slow & stops; won’t start. Could it be a broken compression release spring?

[@fnaguitarplayer9]

These usually do not have a compression release, not like the OHV, i'd suggest pulling the spark plug and cranking it over, it may have filled up with gas if the float stuck in the carburetor. Or it could be a weak starter or battery. Thanks for Watching!!!

[@HolzMichel]

hi fnaguitarplayer9, i have an older 10hp horizontal shaft briggs, presumably 1970's vintage from what i can tell. probably a 233401 series. there's no ID number on the cowling. the piston is 3 1/16 diameter. the question i have and this is something no one has been able to answer: what are the basic jet settings for the carb? one turn, two, three? there are two screws, one at the bottom of the float bowl and another at the top of the carb at the throttle flap. i had the thing running last year and then one of my loving neighbors dumped a quart of water into the gas tank and it hasn't run since. i have drained the fuel, drained and cleaned the carb, but it still won't run. it has compression but it's hard to tell if it has spark since it's a pain to pull the rip cord and check to see if there is a spark. it has fuel to the carb but i am thinking a passage is clogged somewhere and/or the jet settings are whack.... cheers mike

[@fnaguitarplayer9]

I usually set them around 2 turns, but they always need tuned more than that, but that usually always gets them running, it should always at least try to run at that setting on both screws (both mixture screws that is). I'd say you be best off to take it apart and clean it first and go from there, if its got compression and spark it should at least try to run. get back with me if you need any more help. thanks for watching!!!

[@malcolmhughes959]

Hi. I have a 11.5hp version of this motor, can the valves be adjusted without removing too much of the engine??? Don't really want to take it apart (lazy) is there any other reason for engine not turning over??? starter works, battery ok, engine turns when lower pulley turned.Great videos keep up the good work.

[@fnaguitarplayer9]

+Malcolm Hughes Hi. To be honest, not really, you have to pull the head, muffler and carburetor, that will get you to the valves and valve springs. Sounds like the starter may not be engaging properly, spray the gear and spiraled shaft on the starter with wd40 and see if that frees up. If the starter is engaging but just cranks real slow, could be a weak battery or weak starter. Hope this helps, thanks, will do! Thanks for Watching!!!

[@fnaguitarplayer9]

thanks for watching!!!

[@georgemitchell2288]

Any idea where I can find valve stem seals for a 18hp briggs flathead Twin II? I'm in the middle of an engine rebuild and don't like the look of one of them.

[@fnaguitarplayer9]

check on jacks small engine or off of ebay, should have them there. Thanks for Watching!!!

[@fnaguitarplayer9]

@1899lpv i know right. yeah it might, never know haha.

[@fnaguitarplayer9]

@1972FordF150 its a briggs. it will run till the rod is hanging out the side haha yeah it runs good haha just burnt about a half quart oil in 15 minutes LOL

[@shanemurphy498]

hi there. great video . I have a briggs diamond ic 12.5 engine. no problem starting. problem is engine is over revving. checked carb gaskets all ok. checked carb manifold going into casing all ok. governor spring is good - stiff at full throttle - weak at low throttle. engine seems to over rev even at low throttle. any ideas - thanks

[@fnaguitarplayer9]

Shane Murphy Thanks, appreciate that! That might be the governor out of adjustment, thats about the only thing left it could be, OR the oil slinger/governor inside the motor is broken, the weights could be broken. Try adjusting it first, i have a video on that, and if that don't help it might be the internal parts. Also if you can look inside the carburetor (probably have to take it off the motor) check the throttle plate (butterfly valve) its possible its loose and letting the throttle open to much, but my bet is on the governor. Heres the video on adjusting it: kzbin.info/www/bejne/b6OyaXSsedeXm68 Thanks for Watching!!!

[@darkraceing4512]

Im fixing to start working on a engine just like that I was wondering where do you get all the parts to rebuild that engine because I can't find a good place to get all the parts I need and where could I find a book to help me know how to tighten everything to what briggs and stratton want.think you very much if you can help me.

[@fnaguitarplayer9]

Justin Langrell I hear ya! I order most of my parts from tulsa engine warehouse (tewarehouse.com) great place to deal with, except for the flat rate shipping, but it isn't that bad. Also I get parts off of ebay. And sometimes i get parts from parts tree. This paper here should be all you need for torque specs: www4.briggsandstratton.com/miscpdfs/RNT/Engine%20Specifications%20Chart_ms3992.pdf Now if you need more repair, i'd suggest haynes or chilton small engine repair books. Which you should be able to find on ebay as well. Hope this helps! Thanks for Watching!!!

[@12332745]

what is the model, seiral, and type # i have an engine just like this i threw a rod and lost the cover... lol

[@teamwkey9473]

Just re gasketed one of these and cleaned it. Now it wont run without pouring gas down carb. Assuming I plugged something in carb when I sprayed it down. Any issues with the carb on those?

[@fnaguitarplayer9]

Yeah, i'd say just clean the carburetor, might have got some dirt in the bowl and clogged up the jet/nozzle, sometimes it doesn't take much. Thanks for Watching!!!

[@MarkPalmer1000]

With the extent of the wear and damage I imagine it would cost quite a bit more to do all the repairs on that engine than it would to just replace it.

[@dekoldrick]

Have a similar motor that just blew on me caused by an oil leak. Trying to find a cheap replacement because I don't think the motor can be rebuilt.

[@fnaguitarplayer9]

+dekoldrick I hear ya. Sometimes they can be rebuilt sometimes they can't. I've had them throw rods threw the block and I've had them welded up (couldn't do it myself since its aluminum). I only couldn't rebuild one because it hit the camshaft and broke out the camshaft bearing in the block. Thanks for Watching!!!

[@benbentley26]

Hi, I have a question. How would you set up the timing on the engine, once you've torn it down, repaired, and rebuilt?

[@fnaguitarplayer9]

The only timing you have to worry about is the camshaft on the crankshaft and it has timing marks to line up. Thanks for Watching!!!

[@benbentley26]

@@fnaguitarplayer9 Perfect, thanks for replying.

[@chrisfonck4025]

Great video and very helpful. I'm new to small engine work and need help diagnosing an issue. I have about the same B&S engine and it's not getting gas to the carb. Gas it getting to the fuel pump, but not going beyond that to the carb. It has another hose that comes from the block that I assume provides vacuum to the pump? That hose was pretty old and stiff, so replaced that but no change. Got any ideas on what I should be looking for? I first replaced the fuel pump but no change with that either.

[@fnaguitarplayer9]

Thanks, appreciate that. I hear ya, first thing i would do is disconnect the hose coming out of the fuel pump, crank the motor and see if gas squirts out, check the fuel filter, check for pinched lines, and most importantly ( was going to suggest bad fuel pump before i seen that) check for vacuum on the line coming from the block, if there is no vacuum it could be a plugged port on the block or the motor doesn't have a strong enough vacuum to run it. I have hard of peopling having to go with a electric fuel pump, but that is worst case scenario. hope this helps, if not get back with me and i'll figure it out! Thanks for Watching!!!

[@chrisfonck4025]

Thanks for the advise. I tracked it down to no obstructions in the fuel lines and put on a new vacuum hose. Then tried to fire it just putting some gas directly in the carb. It has spark. After a bit started to notice gas dripping from the bottom of the block under the spark plug area. I assume it's not creating any vacuum because the cylinder head is cracked? Is it time to junk the motor or is that a reasonable fix for a weekend mechanic?

[@fnaguitarplayer9]

Chris Fonck It may not be cracked, but I would guess the headgasket may be blown, that would cause that to leak like that and not produce enough vacuum. If all it needs is a headgasket, you can have that done in less than a hour, with basic tools, now if its a OHV motor, you will also have to adjust the valve and replaced the valve cover gasket, but either way its not real real hard to do. if the head is cracked (rare on these motors, but possible) you would have to replace the head. I would suggest finding a used one on ebay.

[@fnaguitarplayer9]

I'm sorry, I only speak english. thanks for watching.

[@rustynuckles3662]

Hey I have a 13.5 I/C that is puffing oil into the air cleaner from the breather element, what causes that?

[@fnaguitarplayer9]

Rusty Nuckles usually to much oil or gas in oil from float being stuck or excessive blow by, usually will be smoking some or the "pcv" valve is stuck or dirty. Thanks for watching!!!

[@Texassince1836]

I/C with an iron sleeve. theres no chance of compression leaks through the crack

[@thedude7726]

These old 12.5 are bullet proof. I have one i burn my old drain oil in and have it as a generator / water pump at my cabin.

[@fnaguitarplayer9]

Yes they are. Do you mean you converted it to run on old oil? Thats really interesting if you did. Thanks for Watching!!!

[@thedude7726]

@@fnaguitarplayer9 it runs on a mix of drain oils/old diesel and gasoline. I have a few friends in various automotive and marine shops that give me the old waste and i burn it in my old modded mower engine. It does not like straight gas anymore as a fuel but I can run it for a week on 5 gallons of gas

[@fnaguitarplayer9]

@@thedude7726 I hear ya! Thats a very interesting setup. I have ran engines on mix of gas and diesel to see what it would do. Thanks for getting back with me.

[@grantw.whitwam9948]

Thanks, I have a 1993 MTD rider with this exact motor. I always changed oil a lot. What caused the one in this vid to overheat?

[@fnaguitarplayer9]

+Grant W. Whitwam Your welcome, this one overheated because the deck on the mower was missing the chute and was throwing grass all over the motor, and grass got into the cooling fins blocking the air flow and it basically cooked itself, my buddies dad lit a cigarette off the muffler on it, it was glowing so red haha I wasn't there or i would have tried to save it. Thanks for Watching!!!

[@grantw.whitwam9948]

I always blow all my mowers off real well with a leaf blower after every use.

[@fnaguitarplayer9]

+Grant W. Whitwam That is a good idea, I usually use a air hose to get most of it off.

[@ANDERSONEXPRESS7]

Hey do they still make rebuild kits for these motors and are these made from a cast iron bore

[@fnaguitarplayer9]

Yeah, its harder to find a "kit" for it, and you usually have to buy parts individually, but yes they are still being made. I just rebuilt one a few months ago. You can also get after market parts alot cheaper too. Some are cast iron bore and some are not, just about all I/C engines are cast iron, but you never know until you tear it down. Alot of power built ones are kool bore, aluminum bore, still great engines but are more apt to have scored cylinders if they were ever ran low on oil, but are still rebuildable usually, but will require chrome piston, and chrome rings. Hope this helps! Thanks for Watching!!!

[@arliskhirsch1074]

When I try to start my mower it will make a thud noise flywheel moves a half turn then locks. what could be the problem Briggs & Stratton 12.5, I have checked all of these, battery fuse, spark plug, fuel and oil

[@fnaguitarplayer9]

Sounds like the motor may have thrown a rod or a valve is sticking or something is on top of the piston hitting the head when it moves up. I'd suggest pulling the head off and see whats going on inside, if the piston isn't moving, thrown rod, if the valves aren't moving, camshaft problem, if all appears to be working but still does it with the head off, it could be the sychro balancer (counterweights). Let me know know what you find out! Kind of curious to know! Thanks for Watching!!!

[@DonovanBryant92]

+Arlis K Hirsch you might have a sheered flywheel key

[@bradmcgill3610]

Mine was doing the same thing top cover bolts were too tight.

[@nutsnbolts76]

I have this same engine. It runs very well, but the crankshaft seal is leaking badly and oil is causing the belt to slip. Can the seal be replaced without opening the crankcase?

[@fnaguitarplayer9]

You can change the seal without tearing it apart, you can usually use a small screw to thread into the seal and then pull it out with pliers or a claw hammer, anything that will get a hold of it, then you will need a piece of pipe that will slide over the crank (thicker wall pipe the better) to drive the seal back in, don't forget to put oil on the seal first. But yeah it can be done, its just a little harder to do. Thanks for Watching!!!

[@foxybrown2]

mine is blowing oil out of the valve cover pipe behind the carb. what does that mean?

[@fnaguitarplayer9]

Usually there are a few things that can cause that, first being to much oil, or to much "oil" from the float sticking and filling the crankcase with gas, making it pump it out, 2nd is excessive blow-by past the rings, if the engine smokes or has low compression its probably from that, 3rd engine overheating, thinning out the oil to much, had this happen on a 12.5, found out ALL the cooling fins were full of grass. 4th is a bad "pcv" valve on the cover, its a small piece of plastic that acts like a check valve in a way and they have been known to go out. Hope this helps! Thanks for Watching!!!

[@BruceCeceMorrisEst1972]

Thanks for posting this. I have one just like it. It isn't charging the battery. What should I look for or do to fix.?

[@Fridgemusa]

Try getting the motor started with a battery that you know is good then use a multimeter to check to see if the voltage changes with higher or lower revs, if not then you might need to replace the alternator coils underneath the flywheel. The alternator sits inside and beneath the flywheel and generates electricity by spinning magnets passing over the coils on the inside of the flywheel.

[@fnaguitarplayer9]

Fridgemusa pretty much summed it up! Thanks for Watching!!!

[@fnaguitarplayer9]

thanks for responding! Thanks for Watching!!!

[@Fridgemusa]

No probs mate, I used to be a small motor mechanic so I've worked on heaps of these motors :)

[@fnaguitarplayer9]

I hear ya!

[@fatback71]

If you dont mind I need those model-type-code numbers off that plz sir, thank you, Fatback71.

[@bigborekit12]

@fnaguitarplayer9 yea i built a custom gear box lotss of work lol but it all paid of

[@karamellkungend2444]

Do you know how many cc this engine is?

[@fnaguitarplayer9]

It is 28 cubic inch (the first 2 digits of the model number) so that comes out to 458.8cc Thanks for Watching!!!

[@bigborekit12]

@fnaguitarplayer9 i just picked up the same exact motor today and boy does that rip in my go kart. no vids because im new

[@thebestgamerstvclubyoutube1441]

I have a 12.5 hp Briggs. When I used it the first time this season, it was hard to start. I replaced the spark plug and air filter. It was still hard to start. I have to use starting fluid to get it to start when it's cold. It overheated, so I noticed that the cooling fins were clogged with old grass and sludge. I cleaned them out. Last week after I started it, it started blowing oil from the valve case through the oil breather into the carb, and was smoking badly. I ordered a new oil breather and tube from ereplacement parts.com. Other than an oil change and replacing these two parts, is there anything else that could be causing these problems? By the way, I bought this mower new back in 1993. So, I know it's entire service history. It's been a good one.

[@fnaguitarplayer9]

Hopefully that is all it is, but If it did overheat real bad and then start smoking, it may need to be rebuilt now, once they overheat, the rings are usually the first to go it seems, hopefully the cylinder is still in decent shape. But it might just need that breather piece because that can cause it too. Thanks for Watching!!!

[@thebestgamerstvclubyoutube1441]

@@fnaguitarplayer9 Thank you. It did smoke some twice before I figured out why. It was after dark those couple of times and kinda cool outside. That may have been one reason. I'm just not trying to think the worst. I think the oil may have thinned also. That may have been part of the reason why oil leaked through the breather tube.I have to add a little oil before mowing because the dipstick tube seal is bad. Question: Can I run the engine with the oil breather off to see if oil is leaking into the valve case? Also, I noticed that the gas level in the tank has gone down some since I took the breather off. I did loose some when I took the gas line off briefly, but I don't think it was that much. I have noticed the smell of gas in my shop. Any suggestions? Thank you for your help. I enjoy your posts! I just went to check the oil and I noticed that all of the gas from the tank was gone. I checked the oil and there is gas in the oil.

[@fnaguitarplayer9]

@@thebestgamerstvclubyoutube1441 your welcome! It could be why, thinning out to much. There will be oil getting into the valve chamber area, there is a small hole that allows oil to get to the valves, but you can run it without it but it will spray oil out.

[@thebestgamerstvclubyoutube1441]

@@fnaguitarplayer9 I drained the oil. There was gas in it. I put fresh oil in and installed the oil breather. It cranked and ran first try. I adjusted the air/ fuel mixture and idle screws. When I put the air filter assembly on it wouldn't crank. I think the governor got stuck because it was back firing through the carburetor. I took the air filter assembly back off. The throttle valve was stuck closed. I loosened the nut on the governor and tried to start it again. No luck. The throttle valve is open, but it's still trying to backfire. What could be the problem?