How to Rebuild a Puch e50 Moped Engine Step by Step

This is a slow bolt by bolt teardown and rebuild of the Puch e50 engine from my 1977 Puch Maxi N. This bike was kitted when rebuilt, but I tried to make this video apply to stock rebuilds as well. Just like almost all Travis Tutorial videos, this video goes slowly as Will and I attempt to explain everything the best we can. This is by no means an all inclusive video, but I hope you enjoy and can laugh along as we don't take ourselves too seriously all the time.
Chapters:
0:00 Tools needed
5:17 Disassembly
32:50 Case Matching
35:22 Washing Cases
36:17 Reassembly
50:00 Ring Installation
53:20 Cylinder Honing
Additional Resources:
www.mopedarmy.com/wiki/Rebuild...
/ e50rebuild
www.mopedarmy.com/wiki/E50_tut...
If you'd like to see the video where I drop the engine off the bike here that is:
• Step by Step How to Dr...
How to set e50 Timing:
• How To Set & Explanati...

[@tomayermusic]

about 6 years ago my brother started getting me into mopeds. once i got my first, we must’ve watched this video 20 times. now we’re grown up, moved out and i’ve got my own fleet of bikes. tearing into the bottom end of one now, i can’t help but feel reminiscent of those “old” days 👍 thank you travis (and will) for passing your wisdom on to all of us

[@TravisTutorial]

Ah I love to hear it! It's wild this video is almost 10 years old. It does get easier, but always fun to look back. Thanks for your kind words!

[@skippygirl959]

These guys seem awesome, its really nice to see people my age who work on things like this and aren't arrogant assholes. I bet it would be a blast to hang out with this group!

[@MegaAwesomedude234]

Awesome video guys, with the crank bearing replacement you'll def wanna use the freezer for your crank. Hammering the bearings can bend the crank. Worked fine with my Honda

[@LyonhartZ2]

Very informative Video. Just a few Critiques.... Always lube the bearings and the Cyl Wall and the bushings... Always Dab both sides of the engine cases lightly (Three-Bond is the Best of all) put Indian head on both sides Cylinder bases gasket and ALSO, when you put the Piston pin retaining clips ALWAYS ALWAYS put a rag stuffed beneath so if you drop the clips, you dont have to take the cases apart looking for the lost clip

[@mrmadmaxalot]

Holy smokes, this was really well put together. Thanks for the vid!

[@restpeaceundead]

Been watching this videoi for almost 2 weeks straight. Can't wait to rebuild my engine lol

[@seandoney9316]

Thanks for doing this guys and for being so specific! 🙏🏼 Mopeds!

[@Dodger2879]

They "hand tightened the bolts" also! They are just better informed in their understanding of mechanical uniformity. I am fixing up a Puch Maxi Mini (strange little thing) moped for a friend and came across this video. Thanks guys. I rebuild/modify Buell and repair old HD motorcycles in my shop and have 1/4", 3/8", 1/2" drive torque wrenches on hand at all times and if I do not know the correct torque setting, I still ensure that if there are 2 bolts or more holding pieces together, they are tightened uniformly. The small Puch aluminum engine that has 10mm studs/nuts holding it together needs all the help it can get. Sat on a hydraulic lift with lighting it does look rather proud, even if it was lifted on by hand not using the ramp and hydraulics! The sad thing about learning by mistake is that the test comes first and the lesson later. I love the steady influx of work with stripped heads, plugs and grenade damaged engines that the shade tree mechanics have wrenched on.

[@thommievg6008]

Travis really appreciate your videos, always helpfull! Please keep making them

[@zx8401ztv]

Nice to see the inside of the old puch engine again, its been over 20 years since i used to do exactly what you just did :-)) A very enjoyable trip to the past travis&mate :-) Cracking job done :-)) Bits: The little end bush is phospher bronze If there is no arrow on the piston, make sure the piston ring pins dont fowl the ports, i think they go eather side of the inlet. Never rebore the chrome pot, sounds like they have changed now. Allways use pink atf.

[@CarmullRolls]

This is the video I've been waiting for!

[@kensmith9334]

Great video on disassembly and assembly!

[@luigiboi357]

im so happy i came across this video

[@gingertimelord5]

will soon be rebuilding my 1976 puch after having it since 1999 (paid $20 for it) and putting on enough mies to have broken the odometer the engine finaly gave up lower ring on the piston broke and wore a hole in the piston, cylinder is badly scored from the ring and the rod bearing on the crankshaft failed .. all in about 30 ft when the broken ring tried to sieze the engine ... it coughtd banked and sputtered and the back wheel locked up for a bit then it took off again and got me home ..... GREAT and very tough little engines

[@jijzer4581]

greath video reminds me of my mopet time tune up and repairings :-) 20 years ago

[@drood78]

loved those Puch engine's. Think i have had 20 or so most of them 70CC one 80CC and one fully 65 polini race kit. Seriously that thing was scary to ride, It destroyed the frame it actually came apart due to the amount of power the engine had ahh the good old times...

[@henkiehenk8527]

i got a polini too i love them

[@brianallen9810]

+jhax78 Great little engine...too bad they mounted the center stand on the case. Only drawback.

[@drood78]

+Brian Allen True that

[@barouzsayguard2301]

A video must be like this can be great help.your explanation is made calmly for better understanding.a little more still close camera about 6 or 8 seconds at moving parts how the engine is working will be very good.thanks for the job you've done.reply.

[@fluffyhamster550]

Nice video, I really needed that information-👍

[@TimODon87]

Thank you for making this video

[@p0w3rfull1]

Great video!

[@macelius]

Whoa, oldie but goodie. "I'm not gonna do that to a Rito crank" Proceeds to hammer the bearings on to one end without supporting it beneath the lobe. I'm sure it was fine tho ;)

[@wojamacolit]

Taking the cylinder studs of would have made your crank case matching a lot easier and also more accurate

[@tn-kt8lg]

nice video, it helped me a lot so far :-)

[@nicoking55]

Great video! thanks

[@anwarhashi7699]

thank you for you help really that was awsome work to learn

[@stefenmorant4778]

You are so right about the crankshaft. Bought a kitted moped and the stock crank failed. I wish I fixed it myself but I didn’t, $700 repair. :(

[@antonioshabaka8363]

Thanks alot. I really appreciate your help :-)

[@schultmi]

Any chance you can go into rebuilding of a Puch clutch?

[@mtxrawkus]

Puch rhymes with "book" btw. :) Great video!

[@TheShowgirl25]

This really exciting! I never knew any of this. Thanks a lot guys. Noticed one thing tho, is it possible to do on ure own?

[@nezerac]

Duuuude. You need to keep making videos. That was awesome. I'm a mechanic, been working on cars since I was 14 but I never touched a bike. Never got my hands on one I could just tinker with and I've wanted a moped since I was like 8yrs old. This was VERY educational. Great to see how much time it really takes to do a rebuild and how much time and funds needed to do it right. One question. What do you thing about replacing all the bearings with ceramic bearings? When I say "all" I mean wheels, engine, and any other bearing that can be swapped with ceramics.

[@TravisTutorial]

Thanks, glad it was helpful! Ceramic bearings, could be nice for wheels - I've read that some ceramic bearings have low (less than 400 degrees) temp ratings which might not be a good idea for inside the motor.

[@nezerac]

TravisTutorial Sounds like a very bad idea actually. But the motor doesn't get that hot does it? I assumed 220 would be the max for something like this.

[@TravisTutorial]

On a stock build, perhaps 220 degrees at the head (which is where the Trail Tech sensor goes), far hotter inside the crankcase

[@nezerac]

TravisTutorial Pretty sure dual ball bearing turbos see more than that and they're using ceramics on those bad boys. I'm really curious now. lol.

[@TravisTutorial]

nezerac Interesting, could very well be fine, I wish I knew more about them - extremely uncommon for someone to spend the money to put then in a moped engine

[@lovedeathdisco]

1:00:33 except when you bring an 80 metrakit to a motorcycle shop on sunset blvd. they point the arrow the other way 🤦🏻‍♂️circa 2016. legend has it the shop is no longer in business and i'm running 70 alukit with piston facing the correct way now 💪🏼🤣🤘🏼

[@thijsiphone]

Nice maxi n you have there and yes im jealous

[@thomwashere6734]

I love the voicecracks hahah great vid btw

[@davidscc32]

Just a heads up, I used a bolt the same diameter as he head of the screw head to substitute for a impact drive.....with a little heat and a couple whacks, the stubborn screws came out.

[@sasagrbavica4487]

Hey man great video and i have a question where can i buy that drill bit for cylinder Thanks :)

[@mrnxdrf1]

Very helpful video! Just wondering about kits and legal issues. In my state 50cc is the limit. Is this one of those things where you can do it and be quiet about it and hope no one will know?

[@Otto_Factory]

Good video but I think the concern about the condensation on the crank was minuscule compared to the beating that poor crank took.

[@SDsailor7]

Hi Travis how about making some videos on how to overhaul/maintenance on rear wheel hubs there are none on YT Thank You

[@adilshorts]

I'm more of a Kreidler guy but like Pich and Zündapp as well. Question: how does the mechanism work that let's you start the engine with pedals, ride the moped with the pedals but not have them rotate all the time?

[@danielmschell]

travis....thank you.

[@steverandall5814]

Using a socket to push the circlips along the shaft and into the groove is easier than using a screwdriver and won't twist the circlip.

[@BigMattJr33]

What did you tighten the flywheel retaining nut to? Did you use any loctite compound?

[@lovedeathdisco]

43:45 good tip! didn't know that.

[@moerman28]

Travis, thanks for posting this tutorial; it was a big help. Question when installing the clutch back should I crank until it snaps in place. I m afraid to over tighten and do not have a special too to measure the torq pressure I am giving. After installing the clutch it would not engage when applying the clutch lever.

[@TravisTutorial]

+Pieter Moerman Once you get it snug with the regular socket driver, just a tiny bit more force is all it needs. I believe that nut calls for 20ft/pounds which is really not that much. I'm not quite sure what you mean when you say it "snaps" into place... As for the start clutch not working when you pull the lever, there a few possibilities. You might need to tighten the cable itself with the adjusters, or it could be the square that sits inside the clutch cover isn't orientated correctly. It is parallel with the cover at rest and when you pull the lever at the handlebars it moves that square to engage the clutch.

[@lovedeathdisco]

Pieter Moerman just being perfectly honest, i was befuddled for 2hrs and realized i did not put my starter plate back in, like a dummy. but the other comment is accurate.

[@motorcrossandgrasstrack9104]

If you have à kickstart maxi. Do you NEED woodruff key for THE clutch? I took my maxi kickstart engine apart and didn't saw à key.

[@MyMegaJOKER2]

Could you exactly list the parts we need for the rebuild?

[@orangegeoff]

Not a good Idea to whack the crank like that when fitting the main bearings as you could easily knock the crank out of alignment. Put a heavy duty plate between the flywheels and and support one side of the flywheel, the one you are hitting, and suspend the other side in mid air.

[@sleepy962007]

38:04 and 38:41 yeah that made me say "noooo!" out loud haha

[@STEFAN123249]

Thx men

[@danstaszko8039]

Puch motors are the best moped/scooter out their and the e50 motor is high quality they don't make engines like they use to. loved the video i myself work on my 77 free spirit moped :) wish more people had them so i could ride with them. What do you think about kits?

[@SilentIns0mniac]

I've got a 78 free spirit. Great bike.

[@TravisTutorial]

A kit could be great if planned out correctly. The brass bushing on the small end of the bearing has a tendency to melt past 9,000rpm so an aftermarket crank is usually seen as a wise investment. Or, you can choose a low end pipe like a circuit pipe combined with some gearing to keep the rpms down if you want to run the stock crank and OG bearings and seals.

[@danstaszko8039]

could i get away with a 70cc kit and change the sprockets to get good speed and keep the stock crank

[@roberthealy8519]

Dan, or Travis I jjust ordered the 70 kit and crank from treats, you say to avoid replacement of the crank change out the sprockets.... to what size? Free spirit puch moped 1978 E50 TU.

[@roberthealy8519]

Or I'll just bite the bullet ,and replace the crank while it's off since it's on it's way.

[@MrKoningluukvlog]

thankss!!

[@chaddancona1157]

Hey man. Ive got a 78' Pinto2 that started making a vibrating noise coming from the head i believe. Any way i could send a video and you could give me your two cents? My mechanic isnt sure what it is without tearing it apart. id rather get some info before i go that route. Thanks. Chad

[@danenakasone7620]

16:51 stamps and brochures

[@kazz330]

Travis, I can't seem to get my case apart. It seems like there's sealant or yamabond type on it and no matter how hard I hit it with a mallet it won't budge. Any tips?

[@TravisTutorial]

+kazz330 I would make sure you truly have every bolt out of the bottom of it, 5 long, 8 short. On my first one there were two that were hidden under grime and I had the same experience as you...

[@Sieist23Jahrealt]

Hi Travis. I recently bought a puch maxi and spaced when putting gas in it and I only ran it for a few blocks or so when I would hear a high-pitched sound like a wheezing sound short and sharp and then the engine would stop it would start up again and run for a few more blocks and then do the same thing until eventually I just walked back to my garage I just now realize what I had done. How long could one of these run on straight gas before major damage is done? If damage is done, what would be the process for repairing my puch maxi? Thank you for any help

[@atraupalin2686]

Running without oil in the mix means drying out your entire engine ultimately. Bearings, seals and clutch could dry up, as well as your piston and carburetor. ALL your shit essentially. I recommend running your ped with a heavier oil mixture for a full tank at least to help lubricate everything. Depending on how it was behaving before you turned it off, you may want to disassemble and lube as necessary..

[@markotacer895]

Hey man. I have tomos pony express at home. I think its around 1983/84. Where can I get parts for it.

[@antonioshabaka8363]

Hey I have a a3 tomos silver bullet. Im looking to enhance the engine with high a performance carb and head. Mabe like a 70cc. Do you know where I can get some of these parts and what would you recommend? Thanks

[@TravisTutorial]

www.treatland.tv for everything. I'd start with a pipe and filter and go from there, if it still has the Encarwi carb ditch that for a Dellorto 14.12 or bigger first. I've never owned an A3 tomos myself, but you can get a good idea of setups people are running on the tuning spreadsheet. www.mopedarmy.com/wiki/Moped_tuners_spreadsheet www.mopedarmy.com/wiki/Performance_FAQ I'd only recommend making the leap to a kit once you really have a good handle on the bike and are comfortable tuning it www.mopedarmy.com/wiki/Kit_a_Tomos_A3

[@jazzbuckeye]

How big of a vise do you think I'd need to hold that cylinder? There's one I'm looking at that opens to 2-3/4 inches.

[@TravisTutorial]

+jazzbuckeye If you're willing to get a little crafty with how the cylinder sits in it, that might be "okay" but ideally you'd want a larger vise

[@domertopinio5007]

Where can I get a magnum puch frame dimension..Puch is very rare here in the Philippines..

[@nathanwhite5090]

Hi, Travis, great video. I am in the middle of a rebuild and wonder if you could answer something for me. The bearings I got to replace the old are Nachi 6203 sealed bearings, they look a little different than the original where they have a rubber guard around the inside. My question is that when I spin the new bearings they seem to have much more resistance than the old ones which spin much easier. Is this normal with brand new bearings and they just need to be "broken in"? Thanks

[@TravisTutorial]

This is where giving advice over text can be tough, the short answer is "yes", new bearings will be a little more stiff than the old ones, but should definitely spin at least a few turns when you brush them with your hand. If they are all the same, and you have them set down all the way onto where they seat on the crank/main gear, they are probably fine.

[@nathanwhite5090]

Agreed, text is not ideal I wish I could get you a picture. The actual bearing says 6203 NRS C3 (plus the circlip one). I don't have them installed on the shaft just free spinning them on my finger. They really didn't even go one revolution. I actually bought these 4 and the oil seals off a kit on eBay for doing a rebuild. I think its the addition of the rubber guard that had me concerned as it is not the same style of what came out of the engine. I am assuming this is how they come now?

[@TravisTutorial]

Sorry missed this comment! Yes, the "RS" at the end of that bearing number denotes the rubber shield, which you can pry off (there are some KZbin videos out there somewhere that show your how). I've never seen an RS bearing on the inside of any motor I've opened.

[@nikolaierikssonkukkonen9878]

+TravisTutorial please can you tell me where you bought that kick stand!!!!!!!!

[@roberthealy8519]

Double nut trick ?.. I'm in the dark on that one, have to convert a Free spirit 49 to 70cc, Enjoy your work TU.

[@lovedeathdisco]

robert Healy robert Healy you thread one nut on, then another, then you unscrew the second inner nut and the one on the outside stops the one on the inside making it so you're able to unscrew the stud. there is also a very useful stud removal tool at autozone for $12 that can save lots of headaches. the studs are M6-100 106mm 15mm of threading on either side. get the good ones on treats $4 ea. 👍🏼7lb-ft. torque, to my knowledge.

[@harleykontra7955]

Does anyone have a .pdf manual for the motor itself? A link or something would be great, trying to get the boy into rebuilding his fist motor. Any help would be great.

[@brucecowgill7672]

Is a ring compressor needed to install the piston if it doesn't come already in the cylinder? Thanks for the vid

[@TravisTutorial]

Most piston ring compressors won't work for this application because you slide the cylinder over the piston, slightly different than a 4 stroke. It's all about nimble fingers and realizing that you'll probably get pinched a little the first time you do it. A good guide you can follow so you don't forget anything is: www.mopedarmy.com/wiki/Install_a_kit

[@brucecowgill7672]

I will check it out, thanks!

[@codelicious6590]

Are there many similarities in Sachs engines to this Puch engine?

[@gordonsuzuki4001]

We're did you find the rebuild kit at or who did you go through? Any info helps thanks

[@TravisTutorial]

treatland.tv will have the seals and bearings under e50, but if you want to source locally: www.mopedarmy.com/wiki/Bearing_and_Seal_Chart

[@d_libby]

Hey guys, I have an e50 with a 65cc kit on a stock crank with the original brass ring. The bike barely had any miles on the original engine as is and I never rip on it too hard. How likely is that brass ring on the crank to fail and would a roller bearing crank install be worth it? Thanks!

[@TravisTutorial]

A kit on an OG bottom end can last a long time, but you have to take care. You want to keep the RPMs under 9K. I would gear the bike to be running lower RPMs at its top speed, and maybe pair it with a lower revving pipe like a circuit pipe instead of a high revving pipe like a Tecno Boss. Marty's Garage has a super handy gearing calculator (and there are also spreadsheets in the MopedArmy wiki) toolbox.martysgarage.info/

[@d_libby]

+TravisTutorial Thanks for the reply man. It is already geared to a 35t rear sprocket with a tecno sidebleed pipe and real 19mm dellorto :) Thanks again great vid!

[@leeverink32]

the torque wrench is over the top i always hand tigthen the bolts

[@SDsailor7]

Will this e50 fit a 1980 Indian (brand) moped? does anyone know?Thank you

[@saidabdala910]

Can i send my 1978 engine in for a rebuilt ?

[@mechanicdave9835]

How do I pull a flywheel off without a flywheel puller

[@marcelmoranc3603]

exelente amigos buen mecanico estoy en chili me llamo cristian moran

[@spctweaks]

Max speed after?

[@Mahdymax]

What’d you torque the spark plug to?

[@TravisTutorial]

Good and tight! :-) If you are counting, around 18ft pounds probably fine: myronsmopeds.com/category/service/torque-specs/

[@mopednyc6338]

Tha GOAAAT

[@henkiehenk8527]

hey travis, youre saying that that puch engine is for a N type puch but that are not the same engines. a N type has a closed clutch thingie ( dont know how to say in english and has a closed elektronic cover. greetz from holland

[@TravisTutorial]

+Henkie henk Hey Henkie, always love to hear from you Europe dudes, definitely some differences with Puchs across the pond. Internal vs external high tension coil, all sorts of stuff! I believe you're thinking of this style e50: www.treatland.tv/USED-puch-e50-engine-old-sealed-unit-p/used-puch-e50-engine.htm ^^^ I have never seen one of those in person, I believe those got phased out in the super early 70s before any were imported to the united states, every e50 I've seen over here on Maxi N bikes or otherwise has had the serviceable clutch cover (and pretty grateful for that haha!)

[@henkiehenk8527]

+TravisTutorial okay, but isnt it an idea to put a kickstarter under it? because than its a puch maxi K which is even rearer.

[@TravisTutorial]

Henkie henk I'm not sure how that would work since the kickstart e50 has a clutch cover of its own: www.treatland.tv/puch-E50-kick-start-clutch-cover-p/e50-kick-start-clutch-cover.htm But, I'll be perfectly honest I know pretty little about European Puch trim levels. Other than horsepower restrictions (intake/exhaust port sizes, different carb internals, etc) most Puch Maxi e50s are about the same over here. All pedals, all serviceable clutch covers, all external high tension coils. Major differences when talking about the top tank Puch Magnum, Magnum X dirt bike, and Manet Korado produced in India, but that's a different story haha

[@lonemeno]

do you use led mixed gas with the oil or oil mix gas?

[@lonemeno]

being how old the motors are and led gas was use back then

[@nikolaierikssonkukkonen9878]

+lonemeno no just 2 stroke mix nothing else

[@ortegaguillermo]

How much the parts cost

[@sevket..]

Usta veyada tamircimisiniz ? Yanlış yaptığınız çok şey var

[@TheShowgirl25]

and the piston u show, well, that piston has been through so much hell and not enuff 2stroke care.

[@frankertsvid3505]

I am from holland Near austria , it is poech or poeg

[@henkiehenk8527]

+FrankertsVid tis poechg

[@lovedeathdisco]

i want the names and addresses of the people who rebuilt an E50 with only 2 screwdrivers! 27:07

[@TimODon87]

check out my newport i just got going

[@notfbi4350]

how old are you? im just wondering because of the voicecracks xD

[@chef9418]

Sorry aber NTN lager werded nd lang hebe😂😂

[@ripemelon393]

It’s a 🐶 not 🤮

[@tpvalley]

pronounced - " P U T S H" not " P U U K"....I think!

[@liltugb0at]

it's not. It's Austrian...

[@jijzer4581]

greath video reminds me of my mopet time tune up and repairings :-) 20 years ago

[@motorcrossandgrasstrack9104]

If you have à kickstart maxi. Do you NEED woodruff key for THE clutch? I took my maxi kickstart engine apart and didn't saw à key.

[@TravisTutorial]

+Motorcross And Grasstrack I wouldn't think so, while I don't own a kickstart e50 the aftermarket clutches for them don't even come with woodruff key slots on the clutch side

[@BK-it6wg]

+TravisTutorial i am getting my maxi e50 in like two days and ive been following your channel and i would just like to thank you for all the knoledge you put on you tube...good luck with the clinton...the buy 2 to make 1 was a great idea.

[@BK-it6wg]

+TravisTutorial also can i use a file instead of a dremming tool.sorry for my english

[@TravisTutorial]

Borut Korosec For case matching? Sure, but it might take along time - best of luck with your Maxi, an e50 is a great place to start!

[@BK-it6wg]

thanks...im kinda thinking of a more custom design...like a 70cc airsal with a 17 carb with some slammed rear shocks ,long seat and some kind of low handlebars etc.