running too rich with 'drilled' jets-adjust slide needle?

philby

finally back online guys... got the 650 back after a big makeover here in the philippines. but the wombat who did it up cut my pipes too short. when he got it running he noticed the carbys were 'running on', so he decided it was running too lean, so he drilled out my jets. now it runs far too rich, you can actually see black smoke coming out the exhaust, and fouls the plugs soooo badly!

well the problem WASNT the jets, it was the bracket he built to hold the carbs on (thus angleing the carbs) and making them suck air! (since then ive got them at the right angle and its running good. since im stuck here with no new jets and wont be back in oz till jann08, how can i remedy this?

does moving the slide needle up or down (the circlip piece?), make it any leaner??? thanks guys, any help greatly appreciated!

xsjohn

What year is your bike.....

John

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

Yes, lowering the needle (raising the clip) will lean it out. This is mostly a midrange adjustment but will have some effect on the upper part of the idle circuit and the lower part of the main circuit.

philby

thanks guys.. the bikes a 1978 model (going by the rear pegs)... the engine and frame #'s match and are 447-904448 . i have been told its a canadian model, but i wouldnt know. also the only 'suitable' plugs i can find here are NGK b8es... do you think these are ok to run and wont damage the motor? (its certainly NOT running lean!).... thanks again....

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

The 8s you're running are one step colder than stock and not the projected tip style. Stock plug is the BP7ES. The "P" stands for projected tip. They shouldn't hurt anything but won't burn as clean or light colored. Over time, you may get more carbon build-up in your heads. Obviously, they're not the best for overly rich jetting, either.

What Happened to 650rider.com?

Yamaha xs650