1988 G1 - rebuilding top end - need advice

[PaulL]

Hi there,

I just picked up a 1988 or 1989 G1 gas golf cart yesterday.
I gave it a tune up - changed plugs, filters, replaced the gas ...
It is very slow to start (gets worse when it gets hot), and will smoke quite bit once hot (blue). It also loses power once hot.

I suspected the smoke was not from oil in the muffler when I noticed the power loss.

I did a compression test ... only 90 to 95 psi.

I pulled the cylinder off, and there is a lot of obvious blowby;



So, obviously, I need at least new rings.

I don't want to dump a lot of money into this cart, so I'm wondering how to determine how much I need to do ...
rings? - yes
top and bottom cylinder gasket - yes
new piston?
needle bearing - probably not
hone cylinder?
bore cylinder?

What is the correct way to rebuild the top end? ... are there certain things that should always be replaced, or should I measure the cylinder and piston, etc.

I'm tempted to just sand the piston clean, replace the rings, and see how it works after that & how much compression it has.

Thanks for the help!

[Herbb2u]

You can hone the cylinder and put in new rings- that probley will solve your compression problem, But usually the seals at each end of the crankshaft need to be replaced too.you can rebuild you engine for about $250.00. I just rebuilt mine and that is what it cost me. But It all depends how much you want to spend and how long you plan on keeping the cart.

[PaulL]

Did yours look as bad as mine?
I guess it might not really be that bad for 20 years old ... but 90 psi is pretty low!

I'm thinking of getting this ebay kit;
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=7215946388

Has piston, rings, and crank seals.

How do you replace the crank seals ... can it be done externally to the lower end?

I think I'll also shell out the bucks for a new muffler ... mine is rattling with junk inside, and I don't think it will ever burn clean.

[Herbb2u]

I got my parts from mountain top golf cars inc. It's called a yamaha top end kit G-1 1978-88. you get everything including a new cylinder. Best way to go I think and the price is right. But you will have to split the crankcase to install the bearings. I did it in 4 hours. I bought a service manual for my cart. best 60.00 dollars I ever spent! I looked at the kit you mentioned- The price is okay but doesn't include bearings.but you may not need them if there is not any up and down play on the crankshaft. good luck. Herbb2U

[Herbb2u]

No My Engine was in good shape, the bearings just went bad and wiped out my coils under the magneto. yours looks worse. Thats why I would change the top cylinder. mine had 100 PSI. moutain top golf carts web site is www.golfcarcatalog.com. good luck HerbB2u

[Herbb2u]

Seals can be replaced externally- but the hardest part is getting the primary sheve off on the clutch side of the motor- need a special puller. the magneto side is easy a standard puller will take it off. but mark everything so it goes back the same way it came off. (coils under magneto control timing) HerbB2u

[PaulL]

I rebuilt the top end, but still had hard starting problems.
I replaced the muffler, and got rid of the smoke.
I replaced the crank seals, and now it works great!

Amazing that a slight leak in the crankcase can cause that much trouble.

[ntonar]

Originally Posted by Herbb2u

Seals can be replaced externally- but the hardest part is getting the primary sheve off on the clutch side of the motor- need a special puller. the magneto side is easy a standard puller will take it off. but mark everything so it goes back the same way it came off. (coils under magneto control timing) HerbB2u

Were do you get this special tool? Is there a way around using the tool?

[PaulL]

I got mine from the 'other' buggy site;
http://tinyurl.com/6btae7

It looks like a small bolt in the pic, but it's actually about 8 or 10 inches long and made of hardened steel.
I've heard folks have hammered the clutch off, but I don't think I could have done it that way.