I'm proud owner of 1984 GPZ750. Bike is in stock, except for the L&W 4-1 exhaust. Stock airfilter also. All jets are stock, main is 110. Bike used to run well, and rev to the red zone with no problem.

The Mikuni BS32SS carburetor had a 1.3-inch bore size, with a standard idle rpm of 1,150, plus or minus 100 rpm. The fuel level measured at 0.2 inch, plus or minus 0.02 inch, and the float height measured 0.88 inch, plus or minus 0.04 inches. The XS650 Garage Carburetor Guide Introduction This manual has been prepared by Grizld1 ( aka Dick Russell, Yamaha 650 Society. OEM Carbs, BS38 (70-79) and BS34.

I had a problem with choke, and removed float bowls, cleaned all circuits. I discovered that float level was WAY high, and returned floats to 18,6mm (factory). Did not mess with mixture on any other adjustment.

Returned carbs on bike. Engine starts perfectly, choke working, but she won't rev over 5000 in any gear. Even in first. Works well until that, and then like it hits rev limiter. Tried to put petcock on prime, nothing. Replaced spark plugs, nothing. Tried to pull the choke, nothing.

Tried to remove airfilter element, even worse! Some people suggest me to put larger main jets.

As i know main jet only affect from 3/4 of throttle to WOT. My problem starts to happen on only one third. Also, if i put WOT, engine dies during driving. Putting throttle to half, returns me to 'rev limiter', and on quarter bike works normally. If not already done, would assure that the ignition timing advancer is properly functioning and not stuck in the idle position. Markovis07 wrote.discovered that float level was WAY high, and returned floats to 18,6mm (factory).( Would also perform the clear tube test on each carb to assure correct fuel levels.

'Float height' measured with carbs on the bench is not a reliable manner to assure correct fuel levels. So long as fuel level is within specs, it doesn't really matter what the measured dry float height happens to be. Good Fortune! My 82 GPZ750 has run all stock jetting and needle settings since it was brand new with a $90 RC Engineering 4-1 pipe I put on it when it was a month old. All Ive done is uncover the mixture plugs and richen them 1/4 turn plus synch them. Still runs perfect and Ive cleaned the carbs several times due to plugged pilots jets. Are you absolutely sure youre measuring to the correct point on the carbs for float height?

Have you tried running it on the manual prime position, perhaps the diaphragm could be going bad in the vacuum petcock? You might have also cut an airbox boot or something removing & reinstalling the carbs. Good luck with it. Hang on a minute.

The bike ran well with the stock jetting. (so leave the jetting alone for now). There was an issue with the choke so you pulled the bowls. While you were in there you fiddled with the float height and set it to ' floats to 18,6mm (factory). ' What the heck kind of float height measurement is that supposed to be??? Trying to set the 'Float Level' is an exercise in futility unless you go back and correctly set the FUEL level using the clear tube method as described in the Kawasaki Service Manual and on this site. You really need to do the clear tube process to CORRECTLY set the height of the FUEL.

Reshebnik po nemeckomu yaziku 6 klass sidorenko palij novaya programma. Otherwise, if the fuel level is too low you can change jets until the cows come home and not solve the problem because the engine cannot run at high rpm if there is not enough fuel in the carb bowls.

Mikuni carburetor operation and tuning Mikuni Motorcycle Carburetor Theory 101 Motorcycle carburetors look very complex, but with a little theory, you can tune your bike for maximum performance. All carburetors work under the basic principle of atmospheric pressure.

Atmospheric pressure is a powerful force which exerts pressure on everything. It varies slightly but is generally considered to be 15 pounds per square inch (PSI). This means that atmospheric pressure is pressing on everything at 15 PSI. By varying the atmospheric pressure inside the engine and carburetor, we can change the pressure and make fuel and air flow.

Atmospheric pressure will force high pressure to low pressure. As the piston on a two stroke engine goes up (or goes down on a four stroke engine), a low pressure is formed inside the crankcase (above the piston on a four stroke). This low pressure also causes a low pressure inside the carburetor. Since the pressure is higher outside the engine and carburetor, air will rush inside the carburetor and engine until the pressure is equalized. The moving air going through the carburetor will pick up fuel and mix with the air. Inside a carburetor is a venturi, fig 1.

The venturi is a restriction inside the carburetor that forces air to speed up to get through. A river that suddenly narrows can be used to illustrate what happens inside a carb.

The water in the river speeds up as it gets near the narrowed shores and will get faster if the river narrows even more. The same thing happens inside the carburetor. The air that is speeding up will cause atmospheric pressure to drop inside the carburetor. The faster the air moves, the lower the pressure inside the carburetor.