How do I know if my carbs have gone bad?

[PiratePast40]

I rebuilt the Solex carbs on my older Volvo AQ130 earlier this year. At the end of the season, I was having problems with cold start and some stumbling on acceleration. First guess is that the floats are sticking, bowls are draining down, the valves are shot, or the accelerator pumps aren't doing their jobs. I've pulled the carbs and plan on doing a complete rebuild with the Volvo kits this time.

I see comments about "the carb is junk" or it's bad but not sure what to look for to make that determination. It's not like it's flashing gang signs or flipping me off - so how do I tell if it's gone bad?

 

[ChrisCraftJohnny]

Re: How do I know if my carbs have gone bad?

A carb that was cared for well. And not used for a commercial craft, should almost last forever with proper rebuilds. Butterfly valves and such will only be worn out if previous owners butchered the carbs.

Almost any carb can be rebuilt. And it's short money. Rebuild 'em. You will be happy you did.

Take your time. Slowly, slowly, slowly. If it takes 2 weeks, it takes 2 weeks.
Be in a good "I feel like doing this mode" when you work on the carbs.

Johnny

 

[ChrisCraftJohnny]

Re: How do I know if my carbs have gone bad?

BTW,

Always go with OE rebuild kits. If it's a Merc, get a Merc kit. Volvo, Etc.

 

[JustJason]

Re: How do I know if my carbs have gone bad?

The only 2 ways I know of to make that dertimination is to first spray some foaming oil on both sides of the linkages on the throttle plate to see if the throttle shaft seals are bad and sucking in the oil. And by taking it apart and looking at it. If its pitted to hell on the inside or if the glazing is gone in spots then chances are the carb is going to leak internally no matter what you do to it.

 

[PiratePast40]

Re: How do I know if my carbs have gone bad?

Thanks for the suggestions - guess I never would have known to look for pitting or missing areas of the glazing.

 

[cr2k]

Re: How do I know if my carbs have gone bad?

Accelerator pumps are a common item to go bad on boats. They do not stay "wet" with gas as we take our boats out of the water for days or weeks between uses or even not use them when they are docked.
Or water in the fuel system causes corrosion and the accelerator pump seems to collect this.

The pump material shrinks, drys up and then wears more when dried out.

This makes the boat stumble or die on acceleration.

The funny thing is the Solex kits are expensive but only have a few parts in them.