Still rough at small throttle openings

[sailorman1617]

Adjusted valves, new plugs, sync'ed carbs (helped some), airbox sealed, no vacuum leaks I can detect. Better but still stumbles at very small throttle openings, like just off idle starting off and including 5th gear up to about 50, then cleans up as the throttle is opened a bit. Runs great otherwise.

I'm assuming I need to replace the O-rings and install a stage 1 Dynajet kit. Had to install a Supertrapp 4 into 1 many years ago when the stockers rusted out. Bike ran terrible until I removed one disc, but still lean. The bike was always cold blooded, even when new; I think '82 was the first year they sealed the air adjust screw.? Takes forever to warm up, pops at idle and trailing throttle, which I'd guess is on the idle circuit regardless of rpm (throttle closed that is).

Any other ideas? Really wish I'd visited here BEFORE I'd rebuilt the carbs

 

[tkent02]

A DynaJet kit has nothing to do with off idle performance. Which technique did you use to set your mixture screws?

Tending to the O rings is always a good idea.

 

[Guest]

Any other ideas? Really wish I'd visited here BEFORE I'd rebuilt the carbs

Try opening the mixture screws 1/2 a turn. While you are at it, confirm they are all set the same in the first place.


Mark

 

[sailorman1617]

mixture screws set at the factory and sealed over. Can't adjust. I believe the stage 1 kit replaces it, supplying a drill bit to 'unseal' it.

 

[jsandidge]

You don't need a kit to do that.

 

[tkent02]

mixture screws set at the factory and sealed over. Can't adjust. I believe the stage 1 kit replaces it, supplying a drill bit to 'unseal' it.

No, it needs to be adjusted, and it needs to be removed so you can properly clean the carburetors and replace the O rings on the screws. The other O rings in the carbs are certainly wasted by now too. Any appropriate sized drill bit will do, then a dry wall screw, just screw it in the hole and pull the plug out. The screw is also factory sealed with paint, that needs to be removed too. It's all in the tutorial...... You have seen the carburetor cleaning tutorial, right?

 

[robertbarr]

Intake o-rings are an investment in your own sanity.

 

[Big T]

Any other ideas? Really wish I'd visited here BEFORE I'd rebuilt the carbs

Yup, because now you need to take those carbs off again and do it correctly.

Check the CV carb cleaning tutorial, do everything in there and I believe you'll find a huge improvement

When you rebuilt them did you use kits? Did you save any original parts?

 

[sailorman1617]

Thanks for the replies. To answer:

As I mentioned, I had not seen this website nor Basscliff's carb cleaning tutorial. But having seen that since, the only thing I really missed were the O rings. The jets were replaced with new OEM Suzuki rebuild kits, after cleaning all passages (I use old guitar strings). Not having any instructions, I did NOT separate the carbs, so the O rings on the fuel tubes were not replaced. And yes, I did save the original jets.

The stage 1 kit is to get rid of the lean condition after replacing the pipes. The bike was lean when the pipes were replaced, probably 20 years ago, that's not a new condition.

I'll probably take care of the sealed air mixture screws when I take care of the O rings and the jet kit. Until then, at least it's running again and other than the mentioned roughness, still a pleasure to ride.