One Cylinder Woes?? (Did the shop try and rip me off?) - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 10 (permalink) Old 04-01-2008, 04:01 PM Thread Starter
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One Cylinder Woes?? (Did the shop try and rip me off?)


I brought my bike out from winter storage about a week and a half ago. I followed the winter storage tips in the Vulcan Verses before storing the bike for winter and it started up fairly easily. I brought it into the bike shop because I wanted a few items done to get the bike in tip top shape for the season. I usually can (and do) most minor preventative maintenance myself, but I wanted to have the shop take a look at the rear spline to ensure that it is lubed. Anyway, a day or so after I dropped it off, the shop called to say that the bike is only running on one cylinder and that they likely will have to pull the carbs to clean them (about $300).

Needless to say, I was surprised to hear this because it was running fine when she woke up from winter (I rode for about a week before dropping it off). I told the shop this and they said that something could have been dislodged during my drive in-and that when they drained the carbs, a decent amount of debris came out. The said that they checked all electrical connections and plugs/etc., but that the problem lies in the carbs, or the one carb. They also said that after getting the bike up to speed, or after it has warmed up, the other cylinder seems to operate fine. I went to the shop today to ride the bike to see what the "problem" is/was. It seemed to run fine and I did not notice any major problems. Obviously, I told them to hold off on the carbs. I figure that I will run a few tanks of gas through the bike (with a healthy dose of Seafoam) to see if there is any difference.

With all that said, I guess I'm wondering the best way to determine if the bike is running on only one cylinder. I would think that it would be fairly obvious if it was, but since I'm a fairly new owner (about a year) I wanted to reach out to the group. Since day one on the bike, it has run great (in my mind). Since there is no major difference in how it runs now vs. how it was running all last spring and summer, I find it highly improbable that I was riding for 6 months on only one cylinder. A bit of background on the bike: '02, 3300 miles, degoated, iridium's, and Big Crank MF Batt.

Also, I sensed that the shop might have been trying to pull one over on's a Kaw/Honda shop, so you would think that they have a clue. The also said that the best way to store a bike for winter is to use Stabil in the tank and drain the carbs, but that differs from the Vulcan Verses storage logic. They also said that it is a major bitch to remove the carbs. I'm not above taking a look in there myself to see what is going on, but I don't want to get in over my head.

What do you think? Do you think it is a good idea to forgo the "carb service?" What can I do to determine if it is running on one vs two? Would keeping a close eye on my gas mileage for the next few tanks be a good idea?

This whole situation makes me really want to do everything myself in the future...even if they are not trying to rip me off!

Thanks in advance all!
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post #2 of 10 (permalink) Old 04-01-2008, 05:35 PM
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How did they define "not running"? Mine was running, but the rear cyl wasn't **firing**, because there was too much gas in the chamber.

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post #3 of 10 (permalink) Old 04-01-2008, 05:59 PM
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If it's running fine, no need to have em pull the carbs.

That said, it IS a major bitch to pull the carbs. Most bikes could benefit from a carb cleaning, especially something 6 years old.

Just because a shop is a kaw shop doesn't mean they know anything - many/ most of em don't. If the bike was running on one cylinder - you'd definitely know it. When I bought my bike (woke from winter nap - not properly stored) it was running on one cylinder and it was quite obvious. Bike ran like crap, had no power whatsoever (topped out at about 45), etc.

I can't see the bike so I can't say for sure that it's running how it should (I can barely do that when I'm on the bike ;-)) But trust your gut.

Might not be a bad idea to follow the clymers instructions on draining the carb bowls so that ya can see how dirty it is in there. Probably wouldn't be a bad idea to run a healthy dose of seafoam through too...

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post #4 of 10 (permalink) Old 04-01-2008, 06:15 PM Thread Starter
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Thanks for the prelim thoughts...

In terms of the "not running" issue, I guess I needed to explain that they stated that it was not firing...all the time. The cylinder would only fire after warmed up or running over 35 mph or so. The tech also said that there are two intake holes into the carbs, one small one and one larger one. The fuel flows into the small hole at low speed and into the larger one at higher speed (I'm not sure if this is true). Again, according to the tech, the smaller hole gets clogged more frequently...and that is what is *supposedly* happening here.

Again, the bike runs no different than it did pre winter nap. I had it up to 70 just over a week ago. I think that I am going to follow your advice Curtis and not have the carbs pulled at this point. I'll see how she runs during the next few tank fulls and I'll hit it with a health mix of Seafoam.

I'm sure everyone would agree that we would rather be riding than be "taken for a ride." I've always been a highly suspicious person and I just wanted to run my thoughts by everyone to see if my doubts were warranted!
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post #5 of 10 (permalink) Old 04-01-2008, 06:47 PM
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You could pull the plugs and see what they look like and compare the front with the aft. Also if you have a spark plug checker, one that lights up as the plug fires will help. You usually just hold the divice on the wire and it will tell you if it is firing all the time. Sea foam at this time is the cheapes way to go until you know for sure you do have clogged carbs. LOL

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post #6 of 10 (permalink) Old 04-02-2008, 07:02 AM
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Curtis is right, if you were firing on only one cylinder - even part of the time - you'd definitely know it. 3000 rpm or 25-30 mph would be about the limit. Go with the Seafoam and a fresh tank of gas and see if that helps (although, since you aren't noticing a problem, could be hard to tell); if you experience problems going forward, shout out - for $300, it'd be worth having the Forum walk you through a carb pull and cleaning.

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post #7 of 10 (permalink) Old 04-02-2008, 05:45 PM
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Your mech is correct in how he described the internal jets in the carbs. However, as has been said, if it was only running on one cylinder, you would know it unless it's always run on one cylinder since you've owned it, which I doubt. On one cylinder, it staggers to 45-50 and even with full throttle, won't go much faster. I had the high speed jet come loose in the rear carb not too long ago and once over 2500 RPM, the rear cylinder would crap out.
Yeah, you'd definitely know if it was running on one. For experimentation purposes, you could disconnect both plugs from one cylinder to show you what a single cylinder Vulcan runs like.

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post #8 of 10 (permalink) Old 04-09-2008, 11:36 AM
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As has been said, I would run Seafoam through it. The max dosage that I would recommend is 1/2 can of Seafoam and fill it up with fresh gas. Also, you can get some carb cleaner, and while the bike is running spray it into the mouth of the carb and into all the holes you see in there. Crack the throttle and spray it into where the butterfly opens. Just be sure not to spray it into the carb while the bike is off. Bad things can happen.

Ask the shop which cylinder is not firing. Then, with the bike completely cooled down, unplug those two plug wires and fire her up. See if she runs different than before. You will definitely notice the difference if it starts at all.

Like weh44 said, pull the plugs and compare them front and back. If it is not firing at any point, you should see some nasty black stuff on the ones that are not firing.

Good luck and keep us updated.
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post #9 of 10 (permalink) Old 04-09-2008, 02:22 PM Thread Starter
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Thanks for all of your ideas! I've since got it back from the shop and it has been running like a champ. (I decided not to let them touch the carbs). I just got back from 75+ mph on the highway. I put in about 1/4 can of Seafoam in there just for good measure. At this point, I'm going with the if it ain't broke don't fix it mantra.

Last edited by dmhnole; 04-09-2008 at 02:23 PM. Reason: spelling
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post #10 of 10 (permalink) Old 04-09-2008, 06:48 PM
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Originally Posted by dmhnole View Post
I just got back from 75+ mph on the highway.
You're running on both cylinders then for sure.

IF it starts to run badly, carefully touch both pipes and see if they are both hot, if not, you'll know which cylinder to concentrate on.


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