Briggs Plastic Cam Gear 

You are so welcome. I love taking stuff apart.

i hate plastic in Motors

You just made my day

You are right. Good point.

I was ready to make this comment & then saw yours. I did not try this (yet) just thought it should work. Did you have a chance to try it out?

Cool Glen.

Thanks a lot. Okie has a good point about the plastic nylon parts actually helping.

Some how I am OK with the nylon gears and other parts of my brain don't like it.

Yes Thanks a lot.

Thanks

Yes i have seen this a few times.

Best of luck. Enjoy the job too.

As you have to open the engine ----just check everything else first. Check the flywheel key first !!!!!! They go before the cam gear.

Yes so dd I but the decompression release was so bent. I could have bent everything back and given it a try though.

Sorry. It is hard to comment on the pressure washer when I am not there

@@BrucesShop I understand. Thanks for always listening to my issues. It’s always good to share with you.

Thanks for the great comment. I remember my first encounter with a plastic cam gear in a Honda and I thought is was so awful but now i am OK with it. It is like stress relief.

Thanks for the kind comment Steve

Thank you Bruce,,you strike me as a person with the heart of a teacher. Thanks for making it easy to do these things..best from all of us

They really must have hit something hard eh!!!

It is a learning process. You are doing great.

Thanks WOW!!!

Right I still think that flywheel key should have sheared but you just never really know what happened.

Can't bend valves on a flathead you can float the valves all day long

If it wasnt made of plastic it probably would not of been a problem. Just got rid of my fathers 40 year old mower and bought one of these plastic mowers, lasted 2 years!

I know righ? I always feel somewhat insulted.. We the buyers, that keep purchasing these throw away mowers, are responsible.. Buy good stuff, kawasaki engines etc.

It already does. Lots of moving plastic parts in an auto engine and they seems to last. I feel both OK and sometimes disappointed with it.

Complete design flaw Bruce points out... That key should have saved the internals. Replacing it should be the only fix necessary!

It was probably 30 or 40 years ago that I heard about an all plastic Ford engine - too lazy to look it up but I found this. blog.caranddriver.com/is-this-the-engine-of-the-future-in-depth-with-matti-holtzberg-and-his-composite-engine-block/ Plastic has its place - in kids toys.

Well there was no pressure release on the rope when it was pulled. When the rope was pulled the entire mower woud move with the rope.

Cool. I don't hesitate on using a non running mower for parts.

Right on. Good for you.

It is more common up here in push mower land. Thanks for the comment Dave

Could be. But with close looking at the key it looks a little crooked in there. If I fix it i will replace the key too.

Well the cam lobes were out at least 20 degrees. i just showed what i found.

Bruce Pender I believe you 100% that the cam timing is off I’m just wondering if it is off because the engine came to a sudden stop or because mounting plastic to metal is just a bad idea and it’s going to happen either way. Keep up the great videos!

Well even the older 6HP mowers have that. I have only changed 1. Have you checked that electric clutch?

You are right but I just fix for myself. I use E replacement Parts to get part numbers.

Yeah, I notice they are just a middle man. I do like their ability to ship fast when they have the parts in stock, however.

I am sorry Goole will work if you type in the model and make of the engine.

That is experience talking. Thanks Robert.

Wow that is weird that even with the air filter assebly is empty it still affects the starting. The age of the Briggs may be an issue. The older ones (pre 1982) need the air filter to be on as the filter bolt closes a hole. But i am guessing you have a newer one. Briggs Classic or quantum. You issue is new t me.

@@BrucesShop The engine itself, like the mower is not to old. Its manufacturing date is: 19/03/2018. Engine model is: 104m02-0010-f1 pretty typical. I starter to tune with this issue... It can potentially be a breather problem. Before engine starts, it has a fresh air to intake, but after some cycles, a dirty, oily air from the engine comes via this breather an reducing oxygen concentration. If the air filter volume is open- the engine can take fresh air, if closed (with filter or without), the circuit is semi-enclosed and this breather tube is inside... It was my guessing only... Otherwise, I have no idea :))) I tried even spray "easy start" - doesn`t work at all. Taking off filter assembly is only the way :)))

What bugs me is that gear should be stronger that the flywheel key. That should shear off first.

@@BrucesShopFWIW, the cam will turn loose without hitting anything. Just a bad design.

Let me know. i am always interested in what others find. Thanks James.

I am going to try and fix this one. I couldn't detect any wobble in the crank. I just used a straight edge though. (old School)

+Bruce Pender ,I have zero doubt that you will make that mower usable again. You have all the skills to bring it back from the dead. Have a great weekend. It will reach 114° in Southern AZ by Monday! SMH

Thanks Dave It is going to 18 Celsius today here in Alberta Canada which is about 65 F.

+Bruce Pender, It sucks to be me. Not really. lol

They all use plastic cam gears now.

Bruce Pender Oh, fair enough. I guess the plastic lobes are somehow “bonded” to the steel shaft, and only come undone when the blade hits a solid object of some kind.

​@@2003cinman Exactly

Bruce Pender I wonder how realistic it would be to drill a small hole through the plastic area between the two cams, through the steel cam and out the other side, then insert a tiny split pin. Maybe it’d prevent such a cam-slip happening again?

@@2003cinman I thought about it.

You are welcome. This is why I got onto You Tube. :-)

Very cool! Best of luck

I think the steek ones don't have the decompression release. They are also very old. like you i have note even seen one. Sorry

Well did you find the issue ?

@@BrucesShop nope.. just picked up another engine for it.. still tryna figure it out though.. I was thinking of putting a fuel filter on it to see if it makes a difference

I have never heard of Greyhound

I am sorry I can't help you.

The majority of them are great. I blame the hard flywheel keys on the Briggs.

I wouldn't but i am 66 years old. LOL

I bet it did. Shearing that blade adaptor must have put some stress on that crank eh!!

You know how they work by the name of your company.

absolutely I do but I never get bored with engineering and tbh not many film a engine in this way. Good stuff Bruce.

They all use plastic.

Cool, thanks

The gear is not keyed. The lobes are not keyed as far as I know. Most manufacturers use plastic cam gears, Honda too.

I just don't understand how they think the lobes and gear will stay properly oriented without being keyed in place somehow....Now, everytime an engine has a strange running issue that can not be easily resolved, the technician will be wondering if the cam gear/lobes are out of position....Oh well, I am probably over thinking all this, as usual....

Yes. You have to be a good scrounger to work on small engines.

Yes it hit something bad.

No don't. All newer engines of that size have a compression release on the exhaust valve. It is internal to the engine. So at very low RPM yo will always read a low compression. I would just make sure the oil is good level and start it up. Don't "fill "the cylinder with oil. Is the motor new?

Thanks Cain

@@BrucesShop welcome Bruce

One just came in that is a year older and has another really bent crank. It is a self propel and is throwing belts. I will use the cam gear from that. Thanks a lot though Bob. Ebay.ca here is a killer on the shipping in Canada but I do use it. You are so right about it not being worth the fix, I have a couple of motors around here in limbo.

Well a couple of years ago when the economy was great they were a throw away item. Now that money is tight more are getting fixed.

OK

What is you valve lash? at Top Dead Centre on the compression stroke.

Please how do I get to no the valve lash,can you send me a video via Facebook or whatsapp

Well it was already broken so you can't break it by taking a look.

@@BrucesShop Great super instructive video sir (from a fellow Canuck, though dislocated). My camshaft on a 15 year old like engine had snapped in two pieces- it came 1 cutting after sitting idle for 3 years, and the self-propel v-belt wedged between the pulley and bottom of sump case. Thanks to your step by step guidance and commentary I mustered up the confidence to pull the engine apart and somehow get it all put back together again. Started up on first pull (well, once I remembered to gas it up).

@@mikeip3191 I wouldn't buy a self propelled, it is just more things to go wrong

I opened my briggs/stratton and I don't see anything that looks out of place but it still doesn't start NO SPARK is the problem the key is not sheared and I don;t see anything else at the moment ANY IDEAS WOULD BE APPRECIATED!!! Thanks

Yes. do the lobs line up with the notch on the wheel?

Used parts are the key to my little operation. In western Canada it takes 2 weeks to get something from amazon. Folks don't realise it but i am a 9 hour drive north of Helena Montana.

My question was prompted by your narration where you say 'I just cleaned up my yard and got rid of my old motors'. Did I misunderstand? I save stuff, maybe obsessively, because my stuff is so old and I figure evolving technology may be able to revitalize damaged components when a replacement is unobtainable. My oldest mower was purchased in 1957 as a share between my father and a neighbor.

Ah yes. I have a shed with a lot of parts but i do tend to recycle the motors that are toast. The ones that have some hope i get running. I have for example 2 Honda boxes, 2 Briggs boxes etc. I am doing good on the reusable parts. Thanks for the great input.

Good morning.

On these the tappets contact right onto the valves. Is the exi overhead valves. This one is a flathead.

Probably. It is easier to look back on a process.

There are lots. Just google Briggs and Stratton Engine parts. The bags are supplied by the seller. For example Craftsman or Yard Machines.

Well you are right. It opens the exhaust valve at low RPM

At 7:02 in the video is the marks for this one.

3.5hp briggs lawn mower

@@ovenox5375 Can I ask a dumb question Has someone changed the flywheel to one with no fins , like a solid cast iron one?

Bruce Pender Nope, they look good and very clean. Engine was overheating before and after I cleaned carb and changed diaphram. I changed oil, and after 30min of working(it had to cool off many times between) it got very black. I am not sure at all what else I can do. Maybe its sucking air from somewhere to run lean? And its very very weird, it sounds normal but it gets really hot after just 10seconds of use and my friend has pretty much the same mower and it doesnt get hot nearly as much. In those 30minutes, I know that first 1 minute engine runs okay.ish, but whet its gets super hot it starts popping from time to time. Thanks for reply

Thanks a lot hunter

Shipping. We use Ebay.ca not Ebay.com

Goos luck

good luck oops

just finish reassembly today !!!!!!!!!!!!!!!! tomorrow try to start welded the scored piston , filed the skirt then painted skirt with dry graphite spray lube , then baked in oven 250c for 1/2 hr, aluminum transfer on cylinder cleaned with muriatic acid , then flapper wheel , then honed with red scotch brite pad, crank and rod ok Rings ok ( reused ), reused plastic Cam shaft

I think they all use them now.

Did you try a different cam gear? Just wondering. Something is still off.

@@BrucesShop good question. I saw you pointed out the exhaust lobe is lined up with that feature on the gear. I'll have to take another look.

Great.

Right I have one but does it have the compression release. The one I have has no little spring?? Great comment I will look again.

just use google. Briggs sumo gasket

franco annoni At least 40 years, Briggs has been using plastic cams and gears.

Thanks Walt yes they have been around a long time.

@@waltschannel7465 Sorry to necro-post but I used to work on this junk in the mid / late 80's for a living. The 9 cubic inch and 11 cubic inch were not plastic in the 80's (3.5 and 4 hp verticals). The 5 hp back then was a 13 cubic inch monster and had a cousin 10 cubic inch vertical beast 4 hp "big block". They were commercial quality engines and were also not plastic. I do remember seeing a 3.5 hp (9 cubic inch) with a plastic cam but it was 90's vintage. I've seen this plastic cam failure in several 12 cubic inch motors though, rated anywhere from 4 to 6.75 hp. Several of them were on pressure washers, they didn't "hit" anything. The earliest one I have is a 1992 based on the "Code" numbers (first two are year of manufacture). The 12 cube stuff is easy to tell visually even without the cowling model numbers because they have a centrifugal governor arm sticking out of the block. Most of the older junk from the 80's back to probably sometime in the 50's had an air vane governor and a diaphragm "mixing valve" instead of a real carburetor. This cam failure makes me sick - 50 bucks for an engine that's worth 40 bucks when it's running. I'm seriously considering one of the comments made earlier, time it and pin it with a roll pin. I'm guessing the cam's shaft is hardened though, probably not worth the effort. I thought by now maybe the Chinese would have ripped off the design and cast up some iron cams, but no such luck. It's a pity to throw out blocks with bores and every other aspect in really good condition because some jack wagon accountant in charge at Briggs wanted to save 1.00 on the cam.

Thanks so much.

Right. They all do.

Well most id not all small engines have plastic cam gears now. It drives me crazy. Even the old Briggs quantums as seen in ths video use a plastic cam gears as do Honda's

@@BrucesShop Almost everyone, not all, has entered the business of planned obsolescence, they know that it is counterproductive to lose trust in a brand, but since they are now so big and can easily create new brands... You have to think very well before and know choosing what to buy and what not to buy, consumers stopped putting pressure on the brands, personally I contact until I find a manager, in general they give me some solution, because it is about talking and reasoning face to face.

Sears is now gone i Canada

yeah most of them are shut down here also

I have a wooden bench, so I frilled a hole in mine to have the engines stand up

Good idea. I finally cobbled up a table stand. It is primitive though.

I think that I may try another cam as well. I have a donor motor from the replacement sump. I will check the cam to see if it has moved thus creating the recoil snap back action. I don't like black and blue fingers.@@BrucesShop

The replacement was plastic too if that is what you are asking. The link to the new part is yes plastic.

@@BrucesShop Thanks was just wondering if you can get a metal one for a degoverned engine

@@Graham_lee I wouldn't de govern a vertical shaft engine since the oil slinger is also the gov gear but a 5hp briggs metal cam should fit

Yes Honda clones are an option. They have improved. That is 105 Canadian about 80 U.S.

It is still a lot of money-

yes

Like Okie says it is like a fuse but the flywheel key should take the stress.

I am familiar with the predator Thanks.

Thanks. This was a popular video.

Clockwise looking from the top

@@BrucesShop thank you , I couldn't remember because I think of that only when I have a problem to solve; but I suppose when you pull the starter it turns it clockwise now that I think of it.

You are watching a lot. Thanks.

Yes you do but they are pretty solid.

I know

If I could find a motor old enough maybe. The plastic cams have been around a looooooong time.

i am shocked the fly wheel key isnt sheared

You are right

I just don't have room for that. Thanks anyway.

They all do it now Honda, Briggs and on.

My favourite colour Plaid Canadian spelling.

Thank you Walter.

Thanks so much Lucas

OK We don't have Harbor Freight in Canada. Princess Auto is our go to store.

Well this motor wouldn't have survived this. Funny the flywheel key was intact eh!!!

I know