Picked up these carbs on ebay...

[kkesler]

And I am worried now. Guy said they were recently rebuilt and had a stage 3 dynojet kit installed. Got them in the mail, opened the box, and man, they looked GOOD. Nice and shiny. So, pulled my stockers and popped them on the 450 and...nothing. Won't crank. Getting fuel but no start. Tried a shot of starting fluid and the bike cranked but won't stay running. Choke, no choke, makes no difference. Bike runs fine when I put my old carbs back on.

The instructions for the dynojet kit said that their kit doesn't effect the idle circuits.

I pulled the bowls and the carbs look as clean inside as out. Floats are close to the right height, needles look good, etc.. In other words, I can't find anything wrong. But I have a grungy old set of carbs that work and a nice shiny set that don't.

Where to look now?

Thanks,
Kurt Kesler
'82 GS850L
'81 GS450S

[shaftzuki]

Kurt - sounds to me like the idle circuits have never been taken care of ... It's a fairly simple process to "dress carbs up", they may look great but they aren't truly clean. Do you know where the idle circuit needles are located on those carbs?? Should be on top of the butterfly cylinder that mates with the intake boots on the head ... look for either a tin plug or you might be able to see the slotted head for the needle. Your going to have to remove them and make sure the passage is clean and that the o-ring, flat washer and spring are in good shape and located where they should be ... 8)

[kkesler]

Will do. The plugs have been removed so I will pull those and take a look tonight.

Kurt

[Anonymous]

just fixed up my brothers carbs. looked great too, dropped bowls, shot all out with carb cleaner, and no starting either.
I bench stripped them and WOW the jets were clogged with some brown gunk.

The best way is to pull one wire off a standard wire brush and use it to clean out all the small holes in all the intakes and jets of those pesty Mikuni CV jobbers. Blast the carb cleaner through every hole untill you see it come out some other hole..

The bike fired up first try.. after I slapped my brother for not priming first.
Stimpy

[shaftzuki]

just goes to show you ... 8)