My Kawasaki Vulcan cuts out around 1/4 throttle

[lowell.stutzman]

Hi,

I'm almost ready to take my bike to the shop. A few weeks ago I was driving along about 80mph and it died. I thought it was out of gas, so I switched to reserve. Still nothing. Until I idled it down and started to pull off the road, then it fired and began running. I could drive up to about 1/4 throttle just fine but when I accelerated more than that, it would cut out. Everything I've read and discussed with people says that this is indicative of my main jet being plugged. With that info, I took it all apart and sprayed carb & choke cleaner in everything to clean it out. Put it back together and still the same issues. I decided to get more serious about it, so I took the carb all apart again--every piece--and I soaked and agitated every part in a cleaning solution. I had the main jet out and it is clearly not plugged. You can look right through it. After cleaning everything a second time, I put it back together and it still has the same issue. I'm a little frustrated with it at this point. Is there anything else anyone can think of that might be wrong? I'm almost ready to give up on it.

[Wrider]

It could be an electrical gremlin. Check your spark plugs and possibly replace them. Do you have a voltmeter? If so check the resistance on the coil packs and leads.

[lowell.stutzman]

I don't think it's an electrical issue. I can spray carb/choke cleaner into the intake and it runs at the higher RPMs. I tried that to determine if it was electrical or fuel. Pretty sure it's a fuel issue.

[GS_in_CO]

I see 2 other Vulcan threads in the troubleshooting forum. Generally similar problems.
Might want to read the other threads for ideas.

[BRUMBEAR]

you know I wonder if they have fuel pumps or gravity fed?

[lowell.stutzman]

Gravity fed to the carburetor bowl.

[BRUMBEAR]

stuck slide? jammed butterfly it's in the fuel delivery either way

[lowell.stutzman]

Thanks for the input everyone. All of the things mentioned were the first things that I suspected and looked for. After I took every piece apart the second time and soaked every piece in carburetor cleaner for a week and agitated the parts and cleaned them up really good, I put everything back together, thinking that the problem was for sure fixed. I started it up again, and the problem was still there. That's when I started this thread.

My last resort was to spray Power Foam into the air intake side of the carburetor while it was running. The can instructed to spray it in as fast as you can without stalling the engine. I blasted it in there while at lower idle, and then revved it up quite a bit while still blasting it in there. It ran at the higher RPMs while blasting Power Foam into the intake because it was running off of the Power Foam. After draining the can, it instructed to let the machine sit for a few hours. I let it set for a day, intending to take it into the shop the next day. Well, the next day I hop on it to limp it into the shop, and it ran like a top at high RPMs! I'm pretty convinced that it was just something in the carburetor blocking or plugging something; I'm just amazed that the problem didn't go away right away after I re-assembled it after the second thorough cleaning. It's a mystery!

[BRUMBEAR]

Awesome you got it sorted, the thing is the varnish that forms from bad gas is very difficult to break down it really is, I have found through the years that scraping down everything possible with a razor blade helps a bit as you rebuild crabs. The other thing is good addatives will aid in the breakdown as well enjoy your machine!!!!