82 650GL breaks up after 5500 RPM

[Old guy]

I'm going through kinda the same thing with my 650. What jets are in your bike now? What did you figure out in the process of getting right?

Do you have an air box lid and filter you're going to be selling?

So basically it was running rich and breaking up?

[mhobryan]

I only checked the mains, and they were the exact same size (can't remember the number, as this was several months ago) as spec for stock. Link for stock spec's are listed on this site. I'm letting the box itself go with the bike - spent an hour getting the Polaris R/R to mount on the bottom; don't feel like undoing my work, and then having to fabricate a new method of mounting it.

I'll have a spare plenum, but you will need both parts.

Yes, in my case it was rich; however, I had been attacking the problem assuming it was lean, as I thought *for sure* it HAD to be lean, as it had a stock main jet.

[tkent02]

Once you get the new Series regulator instlled, the valves adjusted and the cam timing confirmed, you will need to up the main jets a couple sizes and raise the jet needle a bit.

You didn't mention the make of 4-1, a good one like a Kerker will flow a lot more air, and thus require more fuel, some of the crappy ones don't flow much more at all.

[mhobryan]

Once you get the new Series regulator instlled, the valves adjusted and the cam timing confirmed, you will need to up the main jets a couple sizes and raise the jet needle a bit.

You didn't mention the make of 4-1, a good one like a Kerker will flow a lot more air, and thus require more fuel, some of the crappy ones don't flow much more at all.

Assuming this post was for me:

- New regulator installed: check
- valves adjusted: check
- carb sync'ed: check
- restrictive air box removed, pods put back on so carbs breath correctly with jetting did by PO to compensate for pods and pipes: check

She runs great now! I don't know the manufacture of the 4 into 1. Will need to readjust mixture screws, as these were set when I had the airbox on...possibly a carb sync again too.

It's amazing the throttle response on it....would swear it was FI