Damn…I think I just seized my G1 Yammy

[AGELE55]

I think my 81 G1 just ate it. Today I thought I heard a very low volume squeal while driving. I’m still using the original oil pump, so I said to myself… “Self, you need to premix some gas and run it for a while to make sure you’re not hearing a death squeal”.
I mixed up a batch of 100:1 and ran it down the road with th oil pump still connected to slosh the gas around a bit and get the lines cleared of pure gas. Bad plan. I made it just past a the neighbors before it made a sudden stop.

Hmmm…. Now if I grab hold of the crank pulley and try to rotate the motor…no joy. I fear Miss Daisy ain’t driving any more.

[CP241]

Bummer.

Exactly why any 2smoke I’ve ever had the first thing I do is bypass and disable the oil injection. They work great… until they don’t.

It should be saveable though. Tear it down. Find out what’s broken and give Don plowman a call. I think he’s got more parts for these old things than anyone else would.

[SteveCSC]

Don't look at it like a 'bad' thing, look at it as the opportunity to build something bigger/faster/more. Heck thats how I sell it to the wife...

[Leon willis]

Lucky plowman’s sells all the stuff you need to rebuild it but when you reassembled it make shore to put the pistons in the right direction that’s what killed my Harley

[mikeasis]

Originally Posted by AGELE55

I think my 81 G1 just ate it. Today I thought I heard a very low volume squeal while driving. I’m still using the original oil pump, so I said to myself… “Self, you need to premix some gas and run it for a while to make sure you’re not hearing a death squeal”.
I mixed up a batch of 100:1 and ran it down the road with th oil pump still connected to slosh the gas around a bit and get the lines cleared of pure gas. Bad plan. I made it just past a the neighbors before it made a sudden stop.

Hmmm…. Now if I grab hold of the crank pulley and try to rotate the motor…no joy. I fear Miss Daisy ain’t driving any more.

i do hope you fix the old battle axe. great little machines

[AGELE55]

Yes..she shall live again! All it takes is time and money...

[AGELE55]

Update on Ms Daisy:
I’ve removed the engine and begun disassembly. I was expecting to find the top end seized, but surprisingly, the piston and cylinder wall look pretty good. The cylinder lifted up and off with no issues. I did find some metal flakes inside the combustion chamber laying around on top of the piston. No clue yet where they came from.
After removing the clutch /pulley/ flywheels.. etc.. the lower end is seized TIGHT. I played hell splitting the case as it did NOT want to come apart. So naturally I figured the RH flywheel side bearing was seized. Nope. After much persuasion with a my DIY case splitter, (which by the way uses 1/4” steel crossmember) and constant thumping with a rubber mallet, it finally surrendered and came apart. The case splitter steel crossmember actually bowed from the tension. The RH bearing spins freely….hmmm?
So now, it is still seized TIGHT with only the LH bearing holding the crank in place.
Today, I’ll attempt to get it apart without destroying the case.

[AGELE55]

Originally Posted by CP241

Bummer.

Exactly why any 2smoke I’ve ever had the first thing I do is bypass and disable the oil injection. They work great… until they don’t.

It should be saveable though. Tear it down. Find out what’s broken and give Don plowman a call. I think he’s got more parts for these old things than anyone else would.

Maybe you can educate me a bit on the whole 2 stroke oiling process. Yes, I know I pushed my luck too far depending on a 40 year old oil pump, but it now appears my lower clutch side bearing is seized. Wouldn’t a lack of oil cause scoring and cylinder damage before a bearing seizes?
I’m trying to make sure I get this right before I goober up another rebuild. I rebuilt this engine in December of 2020 and drive it daily around the property as my utility vehicle. I say “rebuilt”, actually, I replaced the two lower bearings and seals along with new piston rings. It’s been running great until I noticed the low volume high pitched squeal. Shortly thereafter, it did the sudden seizure.
So did I lose lubrication or simply crap a Chinese bearing?

[augiedoggy]

I still use the oil injection on both my g1s.. ones a 79 and the other is like an 81 I believe.. I've seen many threads where people bypass them and premix and it does burn a lot more oil that way. It also tends to fill the mufflers full of soot and then many either replace them or BBQ then in a fire to try and clean them out.. pick your poison I guess. If you drive the xart for extended periods of time if read it help keep the oil from plugging the muffler as the muffler gets hot enough to burn some of it out. But then that's smoke and stink you will be also dealing with. I have a place at a new campground and no 2 cycles are allowed because of this. Hence my new electric cart.

[Cartmaster]

My guess would be a bad bearing. If the rest of the engine shows no sign of wear or damage, but my guess is as good as yours!