Choke problem

[Mafiera]

Hi
I have a GS750 1977
Every time I start with choke from cold it only revs to about 2500 only briefly I need to give it some throttle to keep it going
I put my mates carbs on it and it revved up to 4000 which is normal
Carbs have recently been thoroughly cleaned etc
Any Ideas?
thanks

 

[Agemax]

You need to be sure that the choke circuit is perfectly clear. There is a long brass tube at the base of the carb which sits in a long recess in the float bowl itself. This is the choke fuel supply. There are tiny holes in the brass tube which block up and there is a tiny orifice at the bottom of the recess in the float bowl which blocks up as well.

 

[Big T]

Sorry, bit they're not clean. Did you follow the tutorial, or just spray some carb cleaner here and there?
If they were clean, you wouldn't have this issue

 

[zed1015]

As already mentioned.
The problem wouldn't be present if the carbs were properly cleaned.
VM carbs are quite simple in operation so it shouldn't be difficult to ensure all the passages are clear.
Close attention needs to be made to the choke fuel pick-ups and also the pilot circuit.

 

[Guest]

Go to Bikecliffs website for tutorials.

 

[Rich82GS750TZ]

Link to BikeCliffs is n my signature. You want the VM Carburetor Rebuild Guide down along the right margin.

 

[bobtail84]

As already mentioned.
The problem wouldn't be present if the carbs were properly cleaned.
VM carbs are quite simple in operation so it shouldn't be difficult to ensure all the passages are clear.
Close attention needs to be made to the choke fuel pick-ups and also the pilot circuit.

Just to add to the mix I had the choke plunger seals replaced and the difference is night and day, if the carbs are 40 plus years old the seals will be shot. I totally recommend getting the seals replaced as they will leak by and make setting the carbs up more or less impossible.