solex carbs -no gas unless choked

[solexcarbs]

I have a Volvo 250 with twin solex carbs 1992 vintage. They will not suck the gas unless you put your fingers into the top of the carbs and in effect choke the inlet. When you remove your fingers the gas stops and the engine stops. Both carbs have been removed and cleaned and found no evidence of anything wrong, When put back together problem persists. Idle and fuel mix screws are set as per manual for this engine-help please!

 

[solexcarbs]

Re: solex carbs -no gas unless choked

I am confused as to why no one has any ideas!!! Am I asking a stupid question or one that no one knows or has any ideas how to solve?

 

[Allbutwet]

Re: solex carbs -no gas unless choked

Hey it sometimes takes a few days. It's a holiday week so allot of guys who would normally be on here are out of town. How is your fuel pressure? When was the last time the fuel filter was changed? And Welcome Aboard.

 

[HalfFish5087]

Re: solex carbs -no gas unless choked

While I do not have firsthand experience, I was trying to assist another iboater with some starting issues with solex carbs. Based on my understanding, the solex carbs have a small channel in the carb that feeds fuel under cold engine conditions. This appears to be done by a temperature controlled vacuum supply that feeds a membrane that should pull a rod to open the channel in the carb. See the manual in the below link. You need to make sure the vacuum lines, temp controlled vacuum switch and membrane.

Boatinfo - Volvo Penta AQ131, AQ151 & AQ171 Engine Service Manual

 

[solexcarbs]

Re: solex carbs -no gas unless choked

While I do not have firsthand experience, I was trying to assist another iboater with some starting issues with solex carbs. Based on my understanding, the solex carbs have a small channel in the carb that feeds fuel under cold engine conditions. This appears to be done by a temperature controlled vacuum supply that feeds a membrane that should pull a rod to open the channel in the carb. See the manual in the below link. You need to make sure the vacuum lines, temp controlled vacuum switch and membrane.

Boatinfo - Volvo Penta AQ131, AQ151 & AQ171 Engine Service Manual

This engine is not equipped with that feature. Very basic no electronics fuel pump mechanically actuated from engine. No cold start features are present.

 

[PiratePast40]

Re: solex carbs -no gas unless choked

Sounds like a rather odd problem. If this is the same as the AQ151, then no, there is no choke. Most of us just give it a few squirts of gas from the throttle and feather it to keep it going until it warms up. The manual provided by HalfFish should be similar to yours.

If there is gas in the float bowls, and the accelerator pumps are working correctly, you should be able to keep the engine running until it warms up. You could try dribbling gas into the carbs to keep it running until warm up so you could then make adjustments to the idle mixture screws.

Sounds like they're set way too lean.