1991 750 project, wont idle

[Richard]

That was not expected as I'm also suspecting the carbs to be the source of your problem...

So after you try to start the engine (without spraying fuel) are the spark plugs wet? We need to be sure some mixture arrives in your cylinders...

Did you check the fuel levels inside the carbs? I also had start issues after I replaced the fuel valves, those aftermarket ones are longer causing the fuel level to become too low.

[Motorcyclelocksmith]

Plugs get a little damp and fuel levels in carbs are good. Hit a wall, so I took it to a friends shop. Will post update as soon as I get new info

[Richard]

a little damp is not good enough, should be soaked after some 30 secs

[Motorcyclelocksmith]

The shop had the bike running for about 30 seconds, until the clutch self destructed, new clutch basket and cover on order.

[Shedman]

Hi, when you say you cleaned the jets with carb cleaner and compressed air, were the jets out of the carbs when you did this? The reason I ask is because carb cleaner hates rubber and makes it swell up, if you have got any carb cleaner on your float valve's rubber tips they could have swollen and stopped the floats from moving.

[Motorcyclelocksmith]

For sure that would be ridiculous to get it on the rubber parts

[Freddy]

Don't worry about rubber parts, worry about yourself. Material Safety Data Sheet for Carburettor cleaner ......

INHALATION OF VAPORS IRRITATES RESPIRATORY TRACT. TYPICAL SYMPTOMS WHEN PERMISIBLE LIMITS ARE EXCEEDED ARE NOSE, THROAT AND LUNG IRRITATION, HEADACHE, DIZZINESS, MUSCLE INCORDINATION, LOSS OF APPETITE AND NAUSEA. CAN HAVE NARCOTIC EFFECTS. EXPOSURE TO HIGHER CONCENTRATIONS CAN CAUSE CENTRAL NERVOUS SYSTEM DEPRESSION, NARCOSIS, UNCONSCIOUSNESS AND EVEN DEATH DEPENDING ON THE CONCENTRATION AND DURATION OF EXPOSURE. http://petraoilco.com/wordpress/wp-cont ... 051711.pdf

No need to use the dangerous shit. Same deal with Brake Cleaner. Just unnecessary potentially dangerous marketing 'solutions' looking for a problem. The mechanical world got on just fine for the first 100 years before these products were 'invented'.

[Motorcyclelocksmith]

So what do you use instead?

[Freddy]

So what do you use instead?

Just blow out all passages and jets with a compressed air gun fitted with a thin nozzle. Then double check the jets are clean by running fishing line through them and scrapping the walls of the jets with it (and then a blast of air again). Neither chemicals or untrasonic cleaners will remove hard buildup inside jets if it is present. It's like cement.

Carburetor cleaner is actually quite ineffective in removing this stuff. So why persist with a potential toxic quite ineffective chemical. Mechanical non damaging cleaning, or complete replacement are the only ways to be certain the jets are truly clean. Just because someone can look through them and see light is a VERY faulty method of determining they are truly clean. About all it tells you is they are not completely blocked. They could be reduced in size 10, 20+% by buildup on the walls.

Unless someone is trying to bring some corroded piece of junk back from the dead, that's all that's needed. Jets being the smallest passages in the carburetor is what will block up.