2002 TXT Low Compression

[posner]

Just picked up a tricked out 02 TXT to use as a pit vehicle for motocross racing. The older guy I bought it from said he had taken the cart to the local service center and had the valves adjusted and the whole thing gone through before selling it. He said he was told the compression was low, but that he was advised to simply run it until he was ready to rebuild it.

The cart runs fantastic on flat and slight hills but came to a stop about half way up a 19% grade with myself and our 9 year old on it. The cart is immaculate, and the motor is no exception. The belt looks brand new, filters clean, etc. My question is, what should I replace? Rings, Pistons/Rings, gaskets, all of it? I dont care if the cart is the fastest around I just want it to run properly. Thanks in advance.

Posner

[mikesmotortoys]

Low compression will do that for sure. So will worn out clutches and belts. You should get a compression guage and test it yourself.

[mgp1974]

what would be ideal compression ?

[mikesmotortoys]

145 in minimum. 160 is a good average to have, but with proper valve adjustments, I've seen them in the 185 to 190 range...

[mgp1974]

thank you

[posner]

I have a compression guage...will verify compression this evening. If it is indeed low like the guy had mentioned, what would make the most sense to replace? Thanks

[mikesmotortoys]

Originally Posted by posner

I have a compression guage...will verify compression this evening. If it is indeed low like the guy had mentioned, what would make the most sense to replace? Thanks

Replace the motor - or send it out for a total rebuild. Where are you located?

[posner]

replace the entire motor? sounds a bit drastic and expensive for low compression. Its not simply a piston/ring or gasket issue? The local service center said he would replace the top end for 800-1000$. I could just buy another motor for an extra 1000 so why bother?

Furthermore, I have been working on 2 stroke and 4 stroke motorcycles for several years and the parts look fairly cheap. Is this something I should not attempt myself? The motor looks fairly simple to me.

[mikesmotortoys]

Originally Posted by posner

replace the entire motor? sounds a bit drastic and expensive for low compression. Its not simply a piston/ring or gasket issue? The local service center said he would replace the top end for 800-1000$. I could just buy another motor for an extra 1000 so why bother?

Furthermore, I have been working on 2 stroke and 4 stroke motorcycles for several years and the parts look fairly cheap. Is this something I should not attempt myself? The motor looks fairly simple to me.

How do you think a low compression motor is fixed? There are many factors involved in rebuilding one. You are the one asking questions here and I am taking time to try to help. Yes, we REPLACE bad motors with new ones. What you chose to do is your option. Without having it in my shop and me personally lok at it, how can I (or anyone else here) give you a diagnostic report?

[posner]

Ok thanks for your help. I will take it to my local shop and get it fixed. I didnt mean to sound unappreciative or rude, I was just asking questions. I am a doctor, I have patients all day long asking me to diagnose problems for them without being seen so I understand it is difficult to say for sure what is wrong. However, I can usually come up with one or two likely scenarios with some input from a patient. Not all headaches are life threatening brain tumors. In my business, when I hear the sound of hooves I think of horses before Zebras. I just thought you might have a likely scenario that I could investigate before taking drastic measures like pulling the motor out and shipping it someplace.