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Discussion Starter · #1 ·
My 2003 runs well but idles unevenly with an objectionable smell of unburned hydrocarbons. The idle speed is within spec and at less than 11,000 mi the bike is still a baby -- no oil burning and no smoke at all. Switched to Iridium plugs with good results. Never had the carbs off but did have a fuel cutout issue last summer that I resolved by taking advice given in this forum and shooting Gumout up into the fuel bowls until they gurgled...Helped a lot. This is a new idle issue though so I don't think the Gumout treatment would work if the jets are not involved.

Any suggestions? Not a big deal but kind of annoying when stopped at traffic signals.
 

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Tried Seafoam? I'd drain the carbs of fuel, replace drain screw, and pour straight Seafoam into both fuel hoses/carbs. Let sit at least 24 hours, drain Seafoam. Add 1/2 can (8 oz.) of Seafoam to a full tank of gas and ride it like you stole it until it is gone. When you can do it safely, wind her up good and let completely off the throttle. Repeat at least six times. If that doesn't fix it, repeat the Seafoam in another tank of gas. If that doesn't fix it, pull and clean carbs.
 

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An strong exhaust smell almost always indicates the engine is running rich, and an uneven idle is also a symptom of that. Pull a plug from both cylinders and see what they look like. You could have a sticking float, or a float needle valve that is not sealing. BTW, I don't recommend spraying Gumout into a motorcycle carburetor. It will damage plastic and rubber parts. I do use it to clean motorcycle carburetors, but only after they have been removed, disassembled, and all the rubber and plastic parts removed. Jerry.
 

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Discussion Starter · #4 ·
Thanks for the suggestions

I will try the seafoam idea -- I did it once but what you are suggesting is way more radical than I did before. BTW I noticed you have a Rebel 250.... if you noticed my handle I paid for the VN750 with a 450 I sold, the only thing is I bought an 87 Rebel 450 -- in excellent shape -- and am hanging on to it until the Smithsonian begs me to donate it to an adoring American public.

I know Gumout can be a problem on rubber -- I didn't let it sit there very long.
 

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I have over 43,000 miles on my '02 VN750, and have never had the carbs off. I have been using Seafoam the way flitecontrol said for some time now, about every 4 months, as preventive maintenance, the avoid having to remove and clean the carbs, a real PITA on the Vulcan 750. I would at least give that a try, buy it sounds like you may have mechanical problems in the carbs, if this happened fairly suddenly. BTW, I also have an '04 Rebel. Great little bikes. Jerry.
 

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I will try the seafoam idea -- I did it once but what you are suggesting is way more radical than I did before. BTW I noticed you have a Rebel 250.... if you noticed my handle I paid for the VN750 with a 450 I sold, the only thing is I bought an 87 Rebel 450 -- in excellent shape -- and am hanging on to it until the Smithsonian begs me to donate it to an adoring American public.

I know Gumout can be a problem on rubber -- I didn't let it sit there very long.
Yah, I'm kinda interested in a CMX450, but not too many around these parts. At least not for sale! Enjoy your stable!
 

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I've never had the carbs off either of my Vulcans. I bought both from guys who rode them often so I have been able to keep them maintained by using seafoam in the gas about once a month. During the winter, when I ride a little less often because of the constant changes in weather, I usually keep a little seafoam in the tank of gas all the time. Knock on wood, I've never had a carb problem with either Vulcan. Other bikes I've owned that I bought and brought back to life were a different story, but after rebuilding and cleaning the carbs, and de-rusting the tanks, I was able to keep the carbs in good shape with nothing but a little seafoam once in a while. As easy as it is to add seafoam, and as much of a pain (I've been told) it is to remove the Vulcan carbs, I can't see why anyone wouldn't use 3 oz of seafoam once a month unless they're in another country and can't get any. Just my .02
 

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Discussion Starter · #8 ·
I'm going to be putting my CMX 450 up for sale as soon as I get the carbs cleaned out. It has been sitting waiting for my wife to get healthy enough to ride it but now that she is better she is not interested.
 

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So how much are you asking?
 

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Discussion Starter · #10 ·
I don't know yet. Probably in the $2500 range. It's in excellent shape -- red, low miles, good rubber, large saddlebags, and most important it has all the documentation -- the original tool kit, original owner's manual, even the original store advertisement. So I think it would be of most interest to a collector, not just someone who needs a transportation bike. I would just hold on to it except that it needs to be ridden because the carbs are real sensitive to stale gas issues. Some said it's the best bike Honda ever made -- hard to argue with that. It's just too cramped for me to ride on extended trips.
 

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Discussion Starter · #11 ·
The one I show on my handle was an '86 which I sold to buy the '87 red one.
 

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sounds like a very nice bike. Know a guy with a '86 Rebel 250 who added Sea Foam to the gas, drained the carbs, fogged the cylinders and left it for 10 years. Put a new battery in it and cranked and ran it with the 10 year old gas! If that isn't a testament to Sea Foam, don't know what would be! He's still riding that bike. I'm sure if you had a place to store it, you could do the same.
 
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