[AngelaB.]

Why would my sons 1987 honda fourtrax 250x not have any compression at all? Im praying it doesn't need a motor. I think he ran it out of oil.

 

[AngelaB.]

When I checked it, it was barely touching the stick and very thin.

 

[shadetree]

no compression at all ?, tells me the rings on piston are bad ?, posb a valve bent/stuck open ? would be my guesses .

 

[shadetree]

and if he did run it without oil ?, very well could have ruined the cylinder and piston !.

 

[AngelaB.]

Shadetree how bad will it be to fix it if the rod and piston is bent?

 

[AngelaB.]

Piston and cylinder sorry.

 

[SamUK]

A top end build here in the U.K. is usually a few hundred pounds, that usually converts to a few hundred dollars. This is a ball park figure of course but it gives you some idea at least.

 

[AngelaB.]

thank you very much so i just need to pull the top end and see how bad it is and go from there. Can these parts be ordered off partzilla?

 

[SamUK]

I’d like to say yes but I’m unsure if all parts are available from them. It may be a case of sourcing parts from a few suppliers. @shadetree will be better versed than me for sourcing parts for your model. I’m sure he’ll be back online soon enough.

 

[fishfiles]

very thin oil could have been from the carb overflowing and leaking fuel into the engine , then the diluted oil didn't do a good job of lubricating ----------- oil at the bottom of the stick isn't a good thing , but shouldn't have caused a failure , the timing chain could also cause low or no compression , a 87 engine with no compression I would think needs a rebuild , which would include jug work or replacing the jug , timing chain , the head worked , and hope that the connecting rod and crank are ok

 

[Goober]

Easiest thing to do is pull the valve covers and see if one of the valves stays open when you slowly cycle the engine. That’s how I found the stuck valve on my ‘87. Cost me $400 parts and labor .

 

[shadetree]

I highly doubt partzilla will have the parts you need for your trx250x ?, as most parts for these old models are discontinued today !. your best bet would be to give psn ( power sports nation ) a call, and see if they have any used parts for your model ?.