87 Venture 2 cylinders not fireing

[Greg Nance]

I have an 87 Venture. The left 2 cylinders will not fire unless I restrict the airflow to the carbs. When I restrict the air a little, both cylinders start to fire. I was told that the carb slide might be at fault as the bike was sitting for a year or so. Is this correct?

[99silver]

Pull the side covers off the carbs and check the slides and the diaphrams.

Hold the diaphrams up to the light and check for holes.

Spray it out w/ carb cleaner and run some Seafoam thru the bugger.

[frankd]

That depends....if they don't fire at idle, but come to life when you restrict the airflow, it sounds like there is a plugged idle passage. If the carbs weren't drained when it was stored the gasoline in the bowls would have evaporated, leaving deposits. These deposits would plug the carb jets and passages, restricting the fuel flow and leaning the mixture.

 

I'm being kind by using the word "deposits". My brother had my old XS-750 which he let sit with fuel in the carb bowls. I pulled the carbs and found that the carb bowls were lined with a green crud. Tidy bowl toliet cleaner will disolve most of the crud.

 

 

 

Frank D.

[MiCarl]

That depends....if they don't fire at idle, but come to life when you restrict the airflow, it sounds like there is a plugged idle passage. If the carbs weren't drained when it was stored the gasoline in the bowls would have evaporated, leaving deposits. These deposits would plug the carb jets and passages, restricting the fuel flow and leaning the mixture.

 

I'm being kind by using the word "deposits". My brother had my old XS-750 which he let sit with fuel in the carb bowls. I pulled the carbs and found that the carb bowls were lined with a green crud. Tidy bowl toliet cleaner will disolve most of the crud.

 

 

 

Frank D.

 

I agree.

 

You'll save a lot of grief if you just go ahead and pull them off for a thorough cleaning and inspection.

[Yammer Dan]

Surest way if they are that bad is to pull and clean them but a strong Sea-Foam soak could save you trouble of pulling them. Do you know how to do that?