Kawi Vulcan 500 won't roll off idle without dying

Gus1300

Gus1300

Joined
Apr 5, 2007
Messages
548
Location
Haymarket VA
Bike
04 1300A
Have to do some work on my son's bike; it has sat for awhile and we drained the gas yesterday (it sat w/ ethanol fuel in it...yes, I know, shouldn't have let it do that, but we're where we are...) but before doing so, started it up again and it still doesn't want to roll off the idle stop without dying. I assume it's a carb jet problem, but don't have a sonic cleaner and haven't ever had one apart before to know what to look for aside from taking the bottom bowl off to see if the float moves freely on the main jet (I assume it does since it started and ran long enough to feed) and whether there's any grunge in the bowl itself. Plan to use carb cleaner but haven't sprayed any into the engine before starting disassembly to see if that would help. Figure that would have been more of a bandaid to the symptom than a healing action anyway, and I want to see what the carbs are all about for my own education in case we run into more issues down the road now that he'll hopefully be riding it more.

Plan to mark the throttle adjustment and any needle valves (turns in to seat then write down to reset upon reassembly, if taken apart) but what else is there to look for as a problem/general maintenance on a carb'd engine? Been only working on my ST, so this is a learning curve for both of us!

Plan to change all the fluids as well, so shouldn't be any issues there once we get it running solid again.

Thanks in advance!
 
Sounds exactly like clogged pilot (idle and small-throttle) jets. If you can get the revs up with careful choke application, then it runs strong, that's definitely the pilot jets. The most you can do from the outside is to drain the tank and carbs, add some Seafoam and fresh gas, making a stronger-than-normal concentration, get it into the carbs, and let it soak for a day or two. You may have to drain the carbs once or twice more.

You should have a good shop manual.
 
Try using some Star-Tron . You'll probably have to clean the carbs though. You don't need a sonic cleaner. Be careful spraying carb cleaning it will ruin the rubber parts in the carbs. I use very fine wire or torch tip cleaners to clean the holes in the pilot jets and the others.

www.vulcanforums.com

How-To: Disassembling the Carburetor on the EN500

Here is my step-by-step how-to on disassembling a Vulcan 500 Kiehn Carburetor. Organization is key. Keep track of all the small parts and remember where they came from. NOTE: This carb is off of a 2000 EN500C. Your carb may differ. TOOLS: 1. Needle-nose pliers 2. 8mm open or box end wrench 3...
www.vulcanforums.com www.vulcanforums.com
 
Last edited:
Adding some of this to your fuel is also great for cleaning out carbs. Not as good as a dissable & clean, but still good.

SeaFoam Motor Treatment.

1591789412684.png
 
Clean the carbs. use a small tip cleaner to scrub em good. If its plugged your probably too late for sea foam. jmo
 
Thanks for the info! Yes, I agree, should have used Sta-bil or Sea Foam or something of that sort. Past that point now though. Got them off and apart...greenish tint to the bottoms of the bowls, one float pretty well covered (primary?) but the other was fairly clean. Threw the jets in some carb cleaner and gave them a good scrub with a toothbrush (didn't want to use anything more harsh) and they cleaned up ok but not great. Prob will try running them with some SeaFoam while waiting to find a rebuild kit if I can get it to run good enough once back together.

I don't know which way this part (16017 below) goes back in though, with the more closed end toward the tip of the needle or the more open end? 1591823403520.png1591823508698.png
It looks based on the parts diagram that it goes back in the center/(main?) hole, but I would swear they both came out of the offset hole, which I believe is the idle jet?

Still pretty steep learning curve on the carbs! And yes, Larry, I should have a parts/service manual for the man cub's Kawi, but he bought it, I didn't. I have one for the ST...we're going down a different path here! Difficult enough getting him off the computer/video games to show any interest in helping to get it running again so we can go riding. But that's for another thread.
 
Last edited:
On my Kawasaki ZR7S the smaller diameter end goes up into the carb body and the larger diameter end goes down to the holder (13901)

As for which hole it came out of if should be the one you can look thru and see up into the carb opening.

When you insert 16017 it should protrude slightly up into the carb.


IMG_5435.JPGIMG_6329.JPGIMG_5439.JPG
IMG_5430.JPGIMG_5431.JPG
 
For cleaning all you need is a can of carb. cleaner. Youtube is your friend for tutorials. Once all rubber is removed, blast out all orifices and channels. they all go somewhere, make sure the blast comes out. Don't shoot carb cleaner in your eyes, it will hurt.

Since you're apart, I'd consider re jetting. Check on any Vulcan specific forums for what works.

All bikes are jetted too lean due to EPA regs. this causes extended warm ups with the choke on, low power, hot running, and blue pipes at the head.
 
Thanks guys! We may rejet at some point, right now just want to get him back up and running so he can refam and we can ride this summer now that he's home again. He'll either be interested enough to continue working on the bike or won't but either way it'll be running vs stationary.

will check out the links nonetheless. Appreciate the help!
 
Check the petcock to verify it's flowing enough gas to get past idle.
 
drtyrrel said:
Try using some Star-Tron . You'll probably have to clean the carbs though.
Click to expand...
I use Star-Tron on my carbureted 1980 CB900 Custom - however, it is not a cleaner, but rather it's an Ethanol neutralizer.
As said in the post above, the best way to clean carbs on the bike is to put half a can of Seafoam in the tank and go out and "ride it like you stole it".
That can work miracles, but obviously only applies if you can keep it running. Otherwise, the carbs have to be disassembled & cleaned.

After you have the carbs cleaned:
Carry some Star-Tron with you, and add some AT EVERY FILL-UP. You will never have carb issues again.
I've been doing that on my CB900, for the past 10 years, and carbs are fine.
Ethanol is your enemy....
 
Thanks for the input above, the couple of rebuild links were very helpful, figured out that the small barrel parts went in with the 'closed' end down and the upper end sticking up in the carb body. Put everything together after 'making' a hole all the way through the pilot jets again with the smallest torch cleaner wire I could find, and at the same time hoping I didn't screw them up too badly to function properly.

Tried starting yesterday with just enough fuel to fill the bowls and had no luck so put everything back together, including the tank, put some gas in it and tried the prime position just for grins. Started up, ran, accelerated past idle without any problems. Plan to get a battery for it when my son is ready to ride again, but in the meantime will drain the gas back out if it stays in longer than a week or so. All the small edge holes in the jets and emulsifier (?) were clear, and I didn't remove the capped jets that were factory set.

Still learning about this bike, but for now it looks like it will run enough for him to show interest again, or not.
 
New AGM battery installed and a test run to the church parking lot and back tonight after putting some air in the front tire and all sounds and feels well. Hopefully we'll get some riding in before the season sets this year. He has to go to CA this weekend for annual drill so it'll be another couple weeks before I can get him on it for any length of time.

'Factory set" also means I didn't have new plugs to replace the old ones, so let it be...for now.
 
  • Like
Reactions: Obo
Glad your getting it fixed up. There is another decent forum, of course not as grand as ST Owners, but a Kawasaki Vulcan Forum search should get you there. Helpful folks with good knowledge for that flavor of ride.
 
You must log in or register to reply here.
Back
Top Bottom