2001 gasgas 250 xc makes a new sounds

[acmetrapper62]

I have a 2001 gas gas 250 xc/ ec model it has 300 low hours on it makin a werid ticking or clacking or some type of sound I never hear before idkk if it the top end needs done or my power valves need cleaned or adjusted. U can notice it at low speeds and idle my air filter was real dirty like bad I changed it and I have this problem there was no dirt in the intake I'm running low octane gas and it suposed to run high octane gas idk if my bearings are bad . I change tranny fluid offen I'm using rotella t6 synthetic oil . Idk I have a race in 2 weeks what should do my self before I take it to someone

 

[Jakobi]

Trying to catch a fish? *nibble nibble*

At 300 low hours I think its pretty clear whats needed.. That's assuming everything is stock. If its already had a few pistons and a bottom end, then perhaps it could be the PV, or pipe mounts, etc.

What you do yourself will depend on your mechanical ability and the time you have to spend working on it.

Quick and nasty test for mains bearings, remove the stator cover, grab the flywheel and see if it has any play up and down. Other than that I'd be looking at pulling the cylinder to visually inspect for damage, and then measuring things up. Generally these 250's like a piston and rings every 100hrs (or less if ridden hard). If the same pistons been in for 300hrs bore is very likely worn as well.

 

[acmetrapper62]

I'm pretty sure it's stock it like a rattle sound do u think my reads are bad u think I runs fine it runs like I bought it It was always woods rode not riden hard never used for motocross could I do a comprsetion test what good compression number I'm pretty sure it's comin from the engine

 

[djroggen]

Pulling the top end off is a small task. Maybe 3 hrs to pull and replace parts and rebuild. Reeds would likely be a problem with starting before they would rattle.

 

[desertgasser300]

300hrs on an original piston and rings is not low. If I were you, I would pull the cylinder off and inspect for wear and if all good with the cylinder put a fresh piston, ring, and gaskets in it.

 

[gassergrant]

Low octain feul make my bike sound like the piston is trying to get out the block lol, it's power valve clatter, piston slap or detienation from low octain feul

:/)

 

[Jakobi]

300hrs is about 3 pistons worth, and time for a bottom end. Thats with a pretty standard trail warriors maintenance schedule. You're rattle could be one of many things from big end to little end, mains or piston slap. You won't know until you pull down and start looking. I know one thing though, ignoring it probably won't lead to a happy outcome (for you or the engine).

 

[acmetrapper62]

I just put 93 octane gas in it idles better and less piston slap but that chadder is still there but I thing it coming head pipe inside that area i don't know it has less than 300 hrs and it has the orgigal brakes and sprockets I'm thinking around 100 hr or less does gasgas are know for power valve chadder or ticking the bike is not hard to start it has a power valve over sized expansion chamber on it idk if it the o rings in the head pipe because it starting to ooze out exh?ust fluid idk what it is