Carb issue.... I think.

[mrpink]

Went for a cruise this evening. Bike started fine, like always. About 10 miles out I noticed that the RPM's were hanging around 3k, then would slowly drop back down to idle speed (I have my idle set at about 1500). I also noticed a bit more backfiring than normal on decel. No noticeable loss in power.

Not wanting to get stranded I turned toward home, but was still pretty far out. I noticed it seemed to get worse (hanging longer and longer). I got back into town and noticed a rough idle, not fouled plug rough, just not as smooth as usual. Seemed like it was wanting to stall so I nursed it home keeping the RPM's up off idle.

When I got home, it did stall out on me. Started right back up but with the same issues. Some black smoke out of the pipes, seemed to be more on the right, but that could just have been my imagination.

I had planned on rebuilding my carbs over the winter so I have all the parts I need for that, I am just wondering if there is anything else I should be looking for. Head gasket maybe?

FYI- I just replaced the throttle cable a week ago with one from 650 Central so I can eliminate that as a suspect.

Thanks

edit: its a 1983 Heritage Special with stock carbs....


p!nK

 

[littlebill31]

Sounds like an air leak. Running way too lean. Check around the carb boots for leaks and the mix screw.

 

[mrpink]

Whats the best way to check for air leaks? I have always just used a can of brake cleaner and spray around the suspected areas listening for a jump in rpms.

 

[weekendrider]

A low battery with the electronic ignition can cause poor proformance.

 

[littlebill31]

Yes, check the battery.
I use propane, DO NOT LITE IT, around the carbs to check. Some of those cleaners, such as starting fluid can damage the rubber parts.

 

[xjwmx]

I've used carb cleaner to find air leaks successfully. The rpms will go down when you hit a leak. As a side benefit, you get clean carbs