Sorry folks,Another carb question again.

[Tompasio]

It is about the choke.Engine cold, i pull the chokelever to max,engine starts up with about 3500-4000 rpm.If i try to lower the lever the engine stalls and die.I must mix the lever up and down until the engine get varm.
Then it idles at about 1300 rpm.Is this normal procedure? And i have not been able to get her running good at high revs.Sparks are white after i tried go at high speed.
GSX 750 ES -1983
Main jet:125
Stock airbox
Needle raised 1 step
Marshall 4-1.
There MUST be a solution for those carb problems??????
Or i am planning to ditch her in the lake.

[robtronic]

did you up jet after adding the marshall pipe? you are super lean, it sounds like. If not bigger jets, or clogged jets if so.

Search for the welcome.... Tons of useful info on the basics about these bikes, new o-rings, get used to hearing that, it's like manditory on these, and a vacuum leak keeps people chasing carb problems forever, so it's best to get everything that could be wrong right before changing variables like jet sizes. I just get lost quick, from my experiance with other carbs.

[chef1366]

First I'd make sure the choke jets in the float bowls and the brass choke rod that goes into the float are clean and clear.
Then I'd take out the idle mixture screws to richen the pilot circuit.
Take out the spark plugs and read them. Are they white? Tan? Brown? Black?

[Tompasio]

First I'd make sure the choke jets in the float bowls and the brass choke rod that goes into the float are clean and clear.
Then I'd take out the idle mixture screws to richen the pilot circuit.
Take out the spark plugs and read them. Are they white? Tan? Brown? Black?

Pilot screws 3 turns out

[earlfor]

It is about the choke.Engine cold, i pull the chokelever to max,engine starts up with about 3500-4000 rpm.If i try to lower the lever the engine stalls and die.I must mix the lever up and down until the engine get varm.
Then it idles at about 1300 rpm.Is this normal procedure? And i have not been able to get her running good at high revs.Sparks are white after i tried go at high speed.
GSX 750 ES -1983
Main jet:125
Stock airbox
Needle raised 1 step
Marshall 4-1.
There MUST be a solution for those carb problems??????
Or i am planning to ditch her in the lake.

Having a 4 into 1 exhaust should not significantly lean the mixtures if you are using a stock airbox and air filter element. When the exhaust gas exits the exhaust port, the engine is through with it. A slight decrease in back pressure has little effect on the ability of the engine to draw air on the intake side. That it takes full choke to start the bike and that it will not run without full choke suggests to me that the choke circuit is clogged.
I also think your idle jet passages are clogged. I dont think you have a jetting problem and I dont think the 4 into 1 is resulting in too much air through the engine. Air intake volume is a constant for each revolution of the engine. Volume only increases as a function of engine speed over a given time. I would remove the carbs, disassemble them and soak them overnight in carb cleaner, reassemble with new "O " rings in, and install them on the bike and do a vacuum guage carb synch.

The 83 model does not have induction boot "O" rings, so that is one possible problem you will not have to deal with.

Earl

[cyclefvr2]

the 4:1 will change the backpressure on it ,that will change the idle, mine does that untill its warmed up, i believe motor is wore out, mine's on the least amount of compression that my manual says it will run on!! and needs the carbs synched (mine)
yours is prolly the same
also check the fuel line for starvation! make sure the bowls are filling
if you had the slides out make sure there in right ,and not over tightened (this might cause a air leak),and they will not work propperly, seal the rim if you need to follow the book
check the connection hoses for air leaks, i believe there all rubber glued/ sealed from the factory, if i remember my manual,this is what i did,as well, not a super glue!! lol you just want to seal them