Yamaha G1 Compression Specs

[djames51]

Hello:

I have a Yamaha G1 Gas golf cart but unfortunately I do not know the year of manufacture. The previous owner welded a new bumper onto the location where the cart identification markings are located.

I just did a compression test (hot engine) and the result was 100 PSI. I don't know if this is a good test result or should I be looking at a top end rebuld.

- Does anyone know what the compression results or average results should be on a Yamaha G1 gas engine?
- Also is there another way of identifying the year of the cart by looking at the engine or the body?
- If I am looking at a engine rebuild, what are the torque settings for the cylinger, head and exhaust pipe?

I can send pictures if it would help to identify the cart

I appreciate any help available.

David
Ontario Canada

[rib33024]

WELCOME----Maybe this will help copy & paste this http://www.tntgolfcar.com/yamparts.php?basemodel=G1A

[GMB74]

When these carts were built, the serial number on the engine matched the chassis serial number. Using the engine number may help you to figure out what you have. Given that these buggies are about 25 years old now, I have found they are often a mishmash of parts from different years, including different engines, so this may or may not help. Fortunately there were few major changes during the G1's lifetime, so most parts interchange even if they are slightly different in appearance.
You can go here to browse parts catalogs from different years. This may help you to narrow down what you have:

http://www.mtsassociates.com/yamaha/cover%20page.pdf

Good compression should be 120-130 PSI with a warm engine, fully charged battery, throttle held wide open, and a clean air filter.
Head nut torque is 18 ft-lbs.

[smallblock450sl]

Originally Posted by djames51

Hello:

I have a Yamaha G1 Gas golf cart but unfortunately I do not know the year of manufacture. The previous owner welded a new bumper onto the location where the cart identification markings are located.

I just did a compression test (hot engine) and the result was 100 PSI. I don't know if this is a good test result or should I be looking at a top end rebuld.

- Does anyone know what the compression results or average results should be on a Yamaha G1 gas engine?
- Also is there another way of identifying the year of the cart by looking at the engine or the body?
- If I am looking at a engine rebuild, what are the torque settings for the cylinger, head and exhaust pipe?

I can send pictures if it would help to identify the cart

I appreciate any help available.

David
Ontario Canada

Yes some pictures of the engine/engine compartment would help identify the cart. 1979 to 1981 (J10 engines) and 1983 and up (J24/J31 should read 120+ and 100 minimum compression at wide open throttle. Only 1982 (J17) the low compression engine , should read 110+ and 90 is the minimum compression. Hope this helps, lets see some pix's. Dave