help what size rings??

[crispy480]

G9 What size of ring set do i need there are standard .25mm and .50mm don't know what to buy from 3R cart parts i have a G9???

[tonyton]

You need the ring set to match the piston(s) in your cart. Standard pistons take standard rings, .25 over pistons use .25 over ring set ....
You need to check the top of the piston. If they are not stamped, they are probably standard. A 0.25 stamp indicates the 1st oversize bore etc....
Depending on your reasons for rings, you may be ahead to have it bored to the next size piston and rings. That is more money and will envolve a machine shop but makes the top end like new.

[crispy480]

Wow thankyou so much!! so when i do take it apart will it tell me what size it is then? cause i need to order a new set cause that cart is smoking, and people have said you may need a new ring and piston set. and its not that much money, but your saying if i do go to the .25 or .50mm i will have to get it bored out, do most machine shops do that kind of thing?? thanks again for all the help!!!
Crispy

[tonyton]

You probably need a motorcycle shop or small engine place to bore it to the correct size.
Remove the head and clean the top of the piston with carb cleaner or degreaser. The piston will probably have an arrow pointing toward the exhaust, maybe a couple letters. Look for an 0.25' or other and you will know what you have. It may be standard?
When you know what you need order it and then take it and the cylinder to the shop. It should be bored to 0.003-0.005mm clearance. The mech will understand that. When you get all back we'll help you put it back together/
If the piston has .50 on it, you can try .50 rings, it cannot be bored more. In this case you buy the whole top end kit. This only requires assembly. No machine shop. Let us know...tony

Oh, yamahas can be bored 4 times! .25, .50, .75, 1.00

[smallblock450sl]

Originally Posted by tonyton

You probably need a motorcycle shop or small engine place to bore it to the correct size.
Remove the head and clean the top of the piston with carb cleaner or degreaser. The piston will probably have an arrow pointing toward the exhaust, maybe a couple letters. Look for an 0.25' or other and you will know what you have. It may be standard?
When you know what you need order it and then take it and the cylinder to the shop. It should be bored to 0.003-0.005mm clearance. The mech will understand that. When you get all back we'll help you put it back together/
If the piston has .50 on it, you can try .50 rings, it cannot be bored more. In this case you buy the whole top end kit. This only requires assembly. No machine shop. Let us know...tony

Oh, yamahas can be bored 4 times! .25, .50, .75, 1.00

Tonyton, you always give good advise, I just need to "butt in", 2 cycles can be bored 4 times....4 cycles only 2. .50 is the max for 4 cycles. Crispy, like tony said, take the head off and look for the "stamping" , probably is "std" and wont have any numbers,just an arrow pointing forward to intake. Cross your fingers. If you do the rebuild, there is help here for teardown and "special" tricks for making it alot easier assembly. Good luck Dave