I rebuilt mine and have run into a lot of tuning issues after putting them back on the bike. Bike sounds like it either can’t supply enough fuel, or supplies too much fuel. Should I adjust valves, cam chain, and ignition timing? The carbs probably hadn’t been cleaned/rebuilt in over a year.
Plenty of places will tell you about the float level adjustment for the CB200 (Australia) but none will say what the level of fluid actually is in the bowl. Reason I am asking is, I have a recently re-built engine that simply is wayyyy to rich on the idle. Cold start is instant with full choke, once running choke is reduced to 1/2, after a short warm up period (approx a further minute) engine is running smooth but then starts to misfire and bog down to finally quit. If I pick up the revs prior to this, it will rev but with the same misfire until it clears the rich mixture from the idle. Release throttle back down to idle, engine again misfires and eventually quits. If I turn off the fuel cock after the initial full opening of the choke, (engine still cold really) the engine runs smooth as until it runs out of go juice. Fuel is everyday run-of-the-mill pump fuel here in Aus ....i.e. unleaded..........no E10 is used what-so-ever. Last week I did add completely fresh fuel...no difference...added some Penrite Octane booster to the fuel...no difference. Plugs are heavy sooted black as midnight. I have chased this problem all over and can only come to the conclusion that it is wayyy to rich for idle. My intention is to run engine and find difference between recommended float level and the point at which it runs smoothly and set the level in the bowl at this. To do this I will fit tubes to the drain plugs in the bottom of both bowls with the open ends above bowl height, mark the present fluid level which was set with the 21mm method, then turn off the fuel cock and run the engine until it lowers the bowl fluid level to give a smooth idle, then mark this height on the outer bowl. Measure difference and adjust the floats to suit this lower level. Floats are currently set to 21mm from (without gasket) carby base, jets are #38 pilot and #85 main, timing spot on, ignition voltage to coil when running 11.9v, plugs standard NGK B8ES ...even tried B6ES. Main slides are set to markings on the slide adjuster screw, idle air screw is adjusted to between 1 and 1.5 turns out from all way in. Slides are correctly installed, main needle is standard size on centre notch. Inherited this bike from my Dad and fitted new rings to newly honed bore, compression check and is fine, all new seals and gaskets, valves checked and are fine, tappets adjusted to 2 thou at correct crank position on each cylinder, new timing and starter chains, valve timing checked and rechecked, new points and ignition timing checked and re-checked. Coils ( fitted as well as spares) checked and tested fine, all result the same.
Is the discharge nozzle supposed to be a tight fit? I replaced mine with the one out of the CMC carb kit and it's loose. it goes in all the way but I can turn the carb over and it just falls out.
👈 didn't put the bowl gasket in square. Old bike/Old eyes
My carb runs lean no matter how i tune it, i already rebuilt it, any ideas why?
I rebuilt mine and have run into a lot of tuning issues after putting them back on the bike. Bike sounds like it either can’t supply enough fuel, or supplies too much fuel.
Should I adjust valves, cam chain, and ignition timing? The carbs probably hadn’t been cleaned/rebuilt in over a year.
Plenty of places will tell you about the float level adjustment for the CB200 (Australia) but none will say what the level of fluid actually is in the bowl.
Reason I am asking is, I have a recently re-built engine that simply is wayyyy to rich on the idle.
Cold start is instant with full choke, once running choke is reduced to 1/2, after a short warm up period (approx a further minute) engine is running smooth but then starts to misfire and bog down to finally quit.
If I pick up the revs prior to this, it will rev but with the same misfire until it clears the rich mixture from the idle.
Release throttle back down to idle, engine again misfires and eventually quits.
If I turn off the fuel cock after the initial full opening of the choke, (engine still cold really) the engine runs smooth as until it runs out of go juice.
Fuel is everyday run-of-the-mill pump fuel here in Aus ....i.e. unleaded..........no E10 is used what-so-ever. Last week I did add completely fresh fuel...no difference...added some Penrite Octane booster to the fuel...no difference.
Plugs are heavy sooted black as midnight.
I have chased this problem all over and can only come to the conclusion that it is wayyy to rich for idle.
My intention is to run engine and find difference between recommended float level and the point at which it runs smoothly and set the level in the bowl at this.
To do this I will fit tubes to the drain plugs in the bottom of both bowls with the open ends above bowl height, mark the present fluid level which was set with the 21mm method, then turn off the fuel cock and run the engine until it lowers the bowl fluid level to give a smooth idle, then mark this height on the outer bowl. Measure difference and adjust the floats to suit this lower level.
Floats are currently set to 21mm from (without gasket) carby base, jets are #38 pilot and #85 main, timing spot on, ignition voltage to coil when running 11.9v, plugs standard NGK B8ES ...even tried B6ES. Main slides are set to markings on the slide adjuster screw, idle air screw is adjusted to between 1 and 1.5 turns out from all way in. Slides are correctly installed, main needle is standard size on centre notch.
Inherited this bike from my Dad and fitted new rings to newly honed bore, compression check and is fine, all new seals and gaskets, valves checked and are fine, tappets adjusted to 2 thou at correct crank position on each cylinder, new timing and starter chains, valve timing checked and rechecked, new points and ignition timing checked and re-checked. Coils ( fitted as well as spares) checked and tested fine, all result the same.
Is the discharge nozzle supposed to be a tight fit? I replaced mine with the one out of the CMC carb kit and it's loose. it goes in all the way but I can turn the carb over and it just falls out.
Awesome carb build vlog
Thanks
Great video, not a lot of footage of the innards of these old keihin carbs it’s much appreciated.
Why not remake it on one video. And you can edit out all the mistakes. Haha