Running Problem

[silvergasgas]

I have a problem with my gas gas txt 300 04,

It was very noisy and poppy when i got it so i repacked my two silencers, It was a lot better it revs up fine and smooth but it pops going back down.

The bike was not taking care of very well when i got it so i am just wondering where i should start from

Cheers

[jse]

I have a problem with my gas gas txt 300 04,

It was very noisy and poppy when i got it so i repacked my two silencers, It was a lot better it revs up fine and smooth but it pops going back down.

The bike was not taking care of very well when i got it so i am just wondering where i should start from

Cheers

I'm assuming that you're asking two questions: (1) what's the possible cause of the popping on off-throttle and (2) what should you look at in order to make sure it's not going to break something in the future.

The first question seems to be an off-throttle lean condition, which may be a jetting problem, and if you are near sea level, here's a ballpark jetting map to start with (each engine is different, so this is only a guide and you'll want to check float level also):

MAIN: 118 (115 OK, NOTHING SMALLER!)

PILOT: 36 (38 OK)

NEEDLE: D36 (3rd, or 2nd CLIP POSITION DOWN FROM TOP)

FUEL SCREW: 3.5 TURNS OUT

The other thing I'd check is for is an air leak, usually in the manifold area, the most common cause is overtightening the manifold, causing the area between the capscrews to bow out. I like to use sealer between the holes where the screws go when installing the gaskets and especially the manifold. Sometimes soapy water sprayed on the various areas when the engine is running will bubble up at the air leak site. With the manifold off, it's a good time to check the reeds for breakage or "bowing" (not laying flat on the sealing area of the cage). In a tight spot, you can sometimes reverse the reeds (turn them over to get them to seal better) to get you through an event, but that is usually only a temporary fix as a "stress riser" was created where the reed was secured to the reedblock, usually resulting in failure in a short time.

The second question's answer is: when buying a used bike, if you want to avoid future problems, don't assume anything has been properly taken care of. You'll want to repack all the bearings, especially the suspension, steering and wheel bearings. I'd get out the owner's manual and renew all the fluids you can. You want to get a baseline for future maintenance and the only way to do that is to make sure everything is in good shape to start with.

Jon

[gasgas]

As Jon said, check the carb settings right away. Never assume that something is by the book and check everything that you feel you savely can do.

Offcourse not everybody is "bike maintenance capable", but try to become one. It will save yr day, one day.