AT MY WITS END!!!!

Hello everyone,

I have 2 BS 34's on my 82 CSR 750 Twin. The problem I'm having is this. I pulled the carbs a couple of days ago to change the slide needles to ones that have adjustable grooves on them. of course I took them apart to make sure that everthing was clean inside and such. I do it every so often (rusty gas tank) . Anyway, everything seemed normal, put the cabs back on today, and turned the fuel on so they would fill up and gas started pouring out of the vent tube that is supposed to only empty gas if the bike is turned over. Took them back off, checked the float levels. everything was right. Put them back on and same issue. pouring gas out of vent tube.

Any idea? Because I don't and this is just reinforcing why I hate carbs.

Eric
82 csr 750

How did you check the floats and why did you take the carbs apart to change the needles? They can be done while on the bike. If you have rust problems with the tank install an in line filter. There are two reasons the float needle will leak gas.
1. Dirt in gas which clogs the needle and does not allow it to seal.
2. Float level is set to low.

Check the float needle it could be getting stuck, tap the float bowls and maybe the vibration will loosen them up, do you have a gas filter ? Needle and seat might need to be cleaned. Hope this helps.

The reason I took them apart was because the filter I use on the aftermarket petcock I use came off and got rust in the carb. I installed an inline filter today as a backup. Anyway, so some issue with the float needle will cause the gas to pour out of the vent tube then?

Yes, and do a clear tube test to set your floats.

Do the carbs at hand have overflow circuits, and if so, is gasoline also escaping from the overflow hoses?

Good Fortune!

and before u are ready to reinstall the carbs....bench test then first....run gas through them to make sure you have no problems.
it sucks when u install and gas is all over the engine or worst inside the engine.

toyotakzrider wrote: Hello everyone,

pouring gas out of vent tube.

Almost always caused by dirty, worn or misadjusted needle/floats.

Or could be a pinhole in the float causing the float to fill up with gas, which can cause an overflow problem

Alright, so I got the overflowing problem solved. the float on the left hand side was WAY off, and I didn't even touch it. Bit it's fixed now. I appreciate it.

The problem that is still happening and the reason why I changed the slide needles is that on part throttle, cruising it's stumbling really really bad. Sounds like it's breaking up. that's the only way I can describe it. At small throttle imput it's fine and at WOT it's fine. but it's that middle throttle point at say 50ish mph cruising it's just horrible stumbling. I had read somewhere that with the bigger jets I put in it (50 pilot, 120 main) that the slide needle needed to be leaned out. Well I ordered needles that had adjustments on them and leaned it out and it's worse than it was.

HELP!!!!

Does your bike have the stock air box and filter on it? Ed

I have the stock air box with an upgraded foam filter, the exhaust has as well been opened up on it, the reason why I put larger jets in it to begin with