G1

[crazyjmk]

So a friend brings me this G1 to fix and I owe him a favor. Stated that he left it out last winter and now it won't start. I look at it and by disconnecting the starter realize that the engine is seized or appears so. I note that the oil injection is crimped and it was not getting much oil if any. I pull the cylinder head and soak with JB and note that I can move the piston either direction about a half inch but it will not cycle. I have put as much torque on the pulley bolt as i dare.

I am thinking something with the crank or who knows. Any insight would be very helpful.

Thanks in advance!

 

[crazyjmk]

So I answered my own question...the bearings are gone/frozen. I have the head pulled and the piston off. Have removed the engine from the cart. The fan is pulled and the electric stuff is off. I have the case split about a half inch and it will not budge a bit.

Is there a snap ring or something I am missing. I am worried that I am going to bugger the case if I keep whacking it.

Thanks in advance!
J

 

[djlan99]

When these are locked up they are no fun to take apart since you need to remove the cylinder.

After removing the flywheel and timing plate there six or seven screws to remove.

I use an impact driver to get them loose. That is the only way to get them out.

You will not be able to get them out with a screwdriver.

They are a no. 3 phillips bit.

I use a puller on each case half as needed.

The bearings are pressed on to the crank and also pressed into the case covers.

The bearings almost always stay on the crank.

I heat them up and burn them off with torches.

You will need a press to put this engine back together by first pressing the bearings into the case halves then press the crank into one of the cases then the other.

Remember you must use a liquid gasket for 2 cycle engines NOT RTV!!!!!!

It will turn into jelly. The new version of yamabond no. 4 is junk.

I would use something from a motorcycle shop. I have found a few brands that are just like the old yamabond 4. It was a rubber type liquid gasket and I used it on everything.

After you pres the engine all together install the screws. You can tighten these with a screwdriver or impact driver until you see the liquid gasket sqeeze out.

I have plenty of matching case halves if you break yours.

Also I can not stress this enough. Use only yamaha crankshaft seals and base gaskets.

The after market parts for these engines are junk! Factory parts are not much more and will last youy 10 years.

The bearings are standard: 3206 and 3306 These are not metric and you can get them anywhere.

The piston rings are very special. They are chrome molly and very soft as to not ruin the cylinder.

The head gasket you can use over. They rarely fail. I have replaced one or two head gaskets in over 4000 engines. They come off in one piece 99% of the time.

 

[Nubs]

4000

thats a lot of stuff right there.

 

[djlan99]

I will still be rebuilding these carts when I am blind, deaf and crippled.

Hell, I`m half way there already!

I had rebuilt over 2000 engines by the time I turned 24 years old and I am now 43.

some of them were from quaker state`s bad batches of oil turning into jelly. (They bought a few engines)

I have seen alot of really bad rebuilds.

Some of these engines I have seen a few times (30 year span) and I never forget a cart even if the owner has changed.

Each cart has it`s own personality.