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  Topic Review (Newest First)
05-17-2010 01:06 PM
Mellow Cant the vacuum line running to the right ear if it is not in correctly make the same kind of issues?
05-14-2010 04:37 PM
AJCruzin Assuming nothing else is wrong (IE spark plugs good, no loose boots etc.) then you probably have the "Kawi midrange stumble" issue. Some, not all, but SOME carb'd Kawi bikes, even in stock form, stumble a bit in the transition from slow jet to main jet. Shimming the needles is about the best way to resolve the problem.
05-11-2010 05:59 PM
wkrizan I believe the air screws affect low and mid range. It seems to me that with a completely stock intake and exhaust system that your issue shouldnt be with a stock needle. Have you check to see if you happen to have a tear in your diaphragm or coaster enricher?

EDIT: 86 above has got a good point there, I'd check that as well, as for a carb sync, build yourself a manometer and give that a shot as well.
05-11-2010 05:54 PM
86blackrigid I am having the same problem and I have a loose spark plug boot and cap. I have new ones on the way... might see if you have something loose down there.
05-11-2010 05:16 PM
nearma12 Everything I stock as far as I know. I have only had the bike for a month or so, so I have not torn into anything yet.

I see the adjustment screws on the side of the carbs, but isn't that only good for low speed? Or am I wrong?

I have worked on lots of carbs from single cylinder bikes before, so I have a pretty good understanding of how they work. Usually they have a pilot jet, main jet, jet needle, and airscrew that can all be changed/adjusted.

As I said before, I only feel the hesitation at 5,000 RPM. I don't feel it above or below that range. So, that leads me to believe that if I change anything I would need to richen the needle position. Main jet seems fine since over 5,000 seems to run good. Pilot seems fine as idle and low RPM performance is good. On my other bikes, the airscrew only effects the lower speed performance.

So, since I am not familiar with the VN750 carbs, I need some advice from someone who is. Could this be a synch problem? If I need to give any more information let me know. Thanks!!
05-10-2010 10:30 PM
wkrizan These carbs do have ajustable pilots yes, one for each carb. If youre running completely stock intake and exhaust and you have lead plugs where your pilot screws are located then you just might have another issue. If you dont have all of the above ie. aftermarket exhaust, earshave, no lead plugs on each of your pilot screws then I'd start messing with them. Need further info to really be of any help.
05-10-2010 09:23 PM
nearma12
Hesitation (Carb Tuning?)

My '92 VN750 is having a problem with hesitation/stumbling around 5,000 RPM. I notice it only in that particular RPM range. It strumbles a lot when cruising at highway speeds, but seems to get better if I choke the carb. I also get some backfiring when I shift gears at that RPM. I don't notice it anywhere else in the RPM range.

So, I am thinking it is running lean. I have already run 1 tank of seafom through, currently working on the second tank.

Should I richen the carb with the screws? Do the carbs have adjustable needles? What should I try first? I was thinking that since it only seems bad at the one point, the needle might help.

Anyone have a suggestion? Thanks

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