Briggs Plastic Cam Gear-Donor Motor

This shows where and how I got the cam gear for the trashed pick Craftsman Briggs and Stratton 7.25 HP mower.

[@CheezyDee]

My friend's mom gave me an old Craftsman mower with a bent crank. Even though I have like 4 other motors in the shed in various states of repair, I just bolted an old adapter to it and beat it with a 2 lb lump hammer until it looked straight, didn't even damage the seal. I also had to weld some fender washers to the deck because the original holes were tore up from the vibration. Been running that mower for 2 years now, although I'm getting tired of dumping the bag every 2 minutes since the blade is not for mulching.

[@BrucesShop]

Yes that is old school. I just can't sell one but one of my own is like it.

[@rustychrome]

This particular motor is my favorite to work on and never had one lick me till recently. Now I suspect the cam. I just never had one go bad before. Looking forward to making my money back on it.

[@BrucesShop]

They are good motors

[@dfields9511]

great vid, this gives me the confidences to take one I have has suspected with the similar fault. I like to tinker into things as a hobby. Always been that way

[@BrucesShop]

Go for it D

[@fleetwin1]

Cool! I wonder if there is any way of checking plastic gear cam lobe alignment on that plastic camshaft other than checking to see both valves are closed at TDC....If Briggs is gonna use cheap pieces like that cam, the least they can do is make it easy for the tech to inspect for proper alignment visually. Interesting about the plastic crank gear as well...I wonder if that is just used on the cheaper mowers, or if it was a materials change on all similar engines....Hopefully the change was from plastic back to a metal crank gear....

[@BrucesShop]

I wondered that too. There was a super thin thrust washer as well.

[@txsviking]

Pretty interesting the difference in the two engines.

[@BrucesShop]

I thought that too

[@sperrytops]

That was great! I think Coors Light needs to give you some money for marketing for them.

[@BrucesShop]

Thanks Joey. I havn't done endorsements but Coors light would be a good one eh!!!!

[@805ROADKING]

Well done Mate!! You have to be a Plastic Surgeon with that newer crap eh!!☺

[@BrucesShop]

Thanks RK

[@garykolo8650]

Bruce, Please consider a Bio video and tell us about you where you live and how you got into mower repair.

[@BrucesShop]

OK I will

[@garykolo8650]

look.at a KZbin channel by MUSTIE1 he is another incredible mechanic who narrates like you.and just fixes stuff. keep up the incredible work.

[@BrucesShop]

OK I will

[@davish50]

From the donor motor you had a plastic drive gear and plastic cam gear. In the repaired motor you will have a metal drive gear meshed with a plastic cam gear. I wonder if that combination is what caused the original cam gear to fail?

[@BrucesShop]

I don't think so. The original motor has a plastic cam and the metal drive . The replacement number is the same for both. Good thinking though.

[@not2fast4u2c]

That is good it was only a short time before you got a donor engine

[@BrucesShop]

You are right.

[@ZippoVarga]

Heya Bruce! Have you ever attempted to straiten the crank shafts and replace the oil seal? It's actually what reputable repair shops do all the time and there is a way to do it without the expensive jig that you see other channels using. I can't count how many I've straitened and they've never come back for any ill effects from the straitening. Just a thought for a future bent crank that you may try. Cheers my Northern Friend! Excellent donor parts for sure! Zip~

[@BrucesShop]

Yes I have but I am just worn out of junk coming in. I do straighten them the old school way. Everything I do is old school.

[@uhrsker]

Dave Rock of Davidsfarm said there is no good way to straighten a bent output shaft. You cannot get an output shaft 100% true once it's bent.

[@billkrause4585]

Put the hammer to the shaft Bruce and get a couple more years out of it. Hey you got the used part you wanted . Cool!

[@BrucesShop]

I thought so too.

[@thistlefarmer9114]

Dear Dr Pender, hope your patient does well after its timing gear brain surgery. I am looking forward to part two showing its full recovery. Is there any truth to the rumor that you are developing a procedure to do this operation endoscopically via the spark plug hole? If so could I suggest that you call it the Pender for Bender procedure. ;-) -1 down here this morning. No T shirts for us. Regards Dr Prickle

[@BrucesShop]

We will do some research on said item mentioned in the memo. There could be several million dollars need to do the research. Well +30 here today. Western Canada. You are obviously south of the equator.

[@thistlefarmer9114]

In Sydney Australia it is a beautiful day in Crookwell Australia it is bloody cold.

[@uhrsker]

Makes me wish I has air tools. How many deck mounting bolts I have snapped the heads of of by trying to muscle bolts out of the deck.

[@uhrsker]

I usually don't try drilling out studs from the block. No electricity in my garage.

[@knighthawk86855]

Very good, glad you found a good donor.

[@BrucesShop]

Transplant surgery.

[@jerryf2426]

PA Lawn Guy. Bruce do you have a skunk definition between a motor versus engine. Thought I had it down but can't prove it.

[@BrucesShop]

Well i guess they are different but sometimes i call them the same thing. Is that what you mean?

[@jerryf2426]

I thought I had a lot of these things figured out but the older (70) I get the more I realize the less I know I do.

[@SteveRobReviews]

Nicely done. Like the shirt too :)

[@BrucesShop]

I thought of you when I wore it.

[@robertyearian227]

Bruce can you tell me or show me a pic where the timing mark is on a plastic crank gear

[@robertyearian227]

The plastic gear that's on the donar motor the small plastic one on crank you got it right there

[@BrucesShop]

There is a small dot on the gear if you look all the way around. Look close.

[@dennispratt3344]

Hello from the UK looking for some advice please! i have a briggs 3.5hp lawnmower wont start done everything possible plug .coil ,valves.keyway , have 80lbs compression, know leakdown ,good spark dead mans lead on & off,clean carb new diaphragms, wont fire with easystart, carb on carb off, new plug just get a small puff back through the intake port camshaft is okay & timing any ideas please or is it ready for the tip thanks great videos

[@BrucesShop]

Well if you have seen the camshaft on the cam gear i don't know what to say.

[@dennispratt3344]

@@BrucesShop ITS RATHER BAFFLING !

[@dennispratt3344]

@@BrucesShop Hi Bruce could you put me onto anyone with great knowledge of small engines with this problem ?? thanks

[@haledmondson2756]

If the 1/4 inch hose can't feed enough air get a air pig at the job end. It will build up a reserve capacity.....Hal

[@BrucesShop]

It was enough. Good idea. What I did was I have an outlet on the compressor upstream of the regulator and I move the reel to that. It seemed to help a lot. I like the idea of a tank or "pig" at the "field end". Thanks

[@SouthpawDavey]

hoe the patient make a full recovery ;-) Great that you found a donor.

[@BrucesShop]

Only time will tell :-)

[@tombruce6398]

Good vid bruce

[@BrucesShop]

thanks

[@Smalltechguy]

Looks like someone over in Canada likes cutting wet grass too....

[@rogeroconnor5182]

great shirt,good thing for donor engines!!!!

[@BrucesShop]

The joke is I bought that shirt and they gave me a case of beer.

[@Smalltechguy]

yeah, you've got quite a few good parts for spares.

[@BrucesShop]

Thanks Paul

[@Smalltechguy]

So it's been 5 years since I watched your video. I am in a pickle on another small engine. I have looked at your marks on your engine and notice that the piston is not at TDC. The recoil was ripping out of my hands even though I knew the timing was correct. I had removed the engine again and left it apart on the bench until I figure something out.@@BrucesShop

[@lmalino695]

Most likely I would have stayed with the original (metal) drive gear which goes against my rearing, which is the plastic gears were meshed together and should be kept together because, being used, there would be additional friction and wear for the unmatched ones to mesh.

[@BrucesShop]

They were both plastic but the first one was black. Sorry if I missed something.

[@jasskunk]

So should we call you Dr. Pender? Keep up the good work!

[@raymondcampbell2346]

Skunk 101 I've been calling him Inspector Gadget. lol

[@BrucesShop]

Za opation vas a zucsess

[@WV591]

i must be the only person in the world that rusty bolts break when taking off. so ez on you tube and no problem.

[@conner5611]

No I've snapped a lot it pisses me off lol

[@johnwojsiat9924]

Alright!, I have the same shirt.

[@BrucesShop]

There are a few around

[@treenopie]

What do you do with the bad gas?

[@mikespain8655]

Dispose of old oil and gas in a regulated site, such as my burn pile.

[@johnclarke6647]

Why did you not remove the oil, first? That way the old gas would wash out the oil from your drain pan. There is nothing worse than an oily drain pan.

[@BrucesShop]

You are tough.

[@philfalz01]

what do you do with your old bad gas

[@BrucesShop]

I use some and take it to the city toxic round up too

[@GlynRobinson]

Good morning, eh. Do you take your bad gas to the same place as your bad oil? Lol

[@BrucesShop]

The city has a toxic round up once in a while