New Piston Rings?

[mrose916]

How would I know if I need new piston rings in my mid 90's G9? It smokes when it runs. Would it need to bored as well? I'm new to the cart world and don't know much about engines. Thank you

[jeff70]

If it smokes while running your oil ring is probably gone, so Ya new piston ring set, (should come with the oil ring) you wont know if it needs bored until you have it apart, On my G2 I was able to just hone the cylinder and install new rings.

[Field6565]

Yes, smoking is a good sign. I would do a compression test.

[mrose916]

I was gonna pick up a compression tester this weekend. How would I know if it needs to be bored? I guess I should just order standard rings? Is it a job I could do myself? I have plenty mechanical ability just not much knowledge on motors. Thanks guys

[raydhd]

I would not order anything unless you have owned from new.It could have oversized rings and piston already.Tear it down and see what you have, after the compression test of course.

[mrose916]

I just bought it last month for $150. The person I got it from definitely had some mental deficiencies. When I got it home I opened the engine compartment to see oil all over everything. On the dipstick the oil was probably close to 2" above the max mark and the air box also had a few inches of oil in it. I drained all the oil out and cleaned everything up. Put in 1 qt of 10w30 and dont see much in the way of leaks but definitely have white smoke out of the exhaust and the engine compartment is extraordinarily hot after running for a few minutes. How would I tell if it has been bored once it is ripped down?

[mrose916]

What should the compression be? If it less than the spec then new rings are needed?

[raydhd]

Minimum is 140 psi.But if you tear down the condition of the cylinder,piston and measurements are all items that need to be considered.Not to mention rod bearing and crankshaft itself.I would really suggest getting the yamaha service manual that is money well spent for any yamaha owner planning any sort of self service work.

[mrose916]

I did buy that on ebay. It is on a cd, thanks for the info

[SkipBo00]

If the oil was that over full and in the air box it probably has the muffler loaded up and is still smoking..... You need to run it a quite a bit and get the muffler heat up good and see if it lets up.. May not need to be torn down.... Oil overfilling on these cause some bad smoke issues..