High revs

[twistednuts]

Went out this morn for what i thought was a short ride, so didnt get any petrol. Ended up tagging along with 3 dudes on big motos, couple of ktms and an aprilia. Really had to thrash the poor crm to keep up.

The revs kept feelin like they were sticking on, as ive mentioned before. Stopped at a roundabout an it started revvin up high on its own. The revs were goin up an down. Then cut out an went on reserve. Im assumin it was suckin loads of air in as the fuel rsn out to make it rev high. So im double assumin the same thing is happening when ridin at high revs. Its not the cable stickin on. Ive done the wd40 trick an theres no obvious air leaks. Would a tiny air leak on carb seals cause such a thing, its really wierd

[knackeredMk1]

You are running lean - Classic symptoms. Go up one size on the main jet. If it continues go up another.

[twistednuts]

Wll do squire. Gonna totally attack carb with bigger mains an pilot, an may push the boat out with new seals.

Cant understand why it should run lean when everythin is standard? Could it be an age/worn situation?

Would raisin the needle a notch help until the new gubbins arrive?

[knackeredMk1]

Raising the needle would help a little.

[fallenmikethebike]

A generous dose of filter oil on the filter helps to not only keep out the crud, which is good, it also slightly enriches the mixture
Doesn't need to be swimming in oil, just the usual application.
Mike

[twistednuts]

Tis well soaked mike. Ive even left the baffle thing in the air box. Air screw is very slightly less than One an a quarter turns. Would an half blocked pilot jet make it lean?

Anyway, its probably a collection of small issues so i'll treat the carb to new stuff.

[twistednuts]

One thing i did notice is someone has drilled a few holes in the air box under the ecu. But i thought the actual ecu would almost seal em up. I'll cover them woth duck tape an all

[fallenmikethebike]

You are running lean - Classic symptoms. Go up one size on the main jet. If it continues go up another.

+1, There are so many areas in a two stroke that can allow unwanted air into the combustion system.
Case jointing faces, reed valve assembly faces,base gasket, crank seals.
Cleaning the pilot jet is often ineffectual, so best replaced.
My MK3 runs rich on standard jets, so I have had to lean it of on the needle clip by 2 notches, and its still just slightly rich.
Mike