2004 Vulkan Classic 1600 issues

[Mystussnake]

Hey Everyone, Thanks upfront for any help that is provided. I recently (2 m onths) purchased a used 2004 Vulkan Classic 1600 with 27,000 miles on it. Since that time I have put 2000 miles on it (as of yesterday) around 1200 miles it started "acting up" on me. I would like to premise that the gentleman that owned it before me took real good care of it. I spoke to the shop where he mentioned that he had it serviced and they confirmed this. I have it scheduled to go into that shop in 2 weeks (they are back up that far) but I wanted to look at a few things before taking it in. What is occurring is after about 20 minutes or so of riding the bike starts to "stutter" almost as if it is not getting enough gas. It doesn't seem to do this much in high RPMs although occasionally it still does when reved. It does this most at cruising speeds between 40-60 although it does it occasionally at other speeds as well. I checked the spark plugs and although they were "ok" I changed them out for new ones. I also checked the air filter which was somewhat dirty and clogged near the top of the filter. The rest of the filter was clean. It is a reusable K& N filter so I bought a kit, washed it, recharged it and put it back in. My bike ran better but the issue did not go away. It seemed to prolong how long it took to start "acting up" Instead of 15-20 minutes of riding it now takes about 20- 30 minutes before it starts acting up, but that may just be anecdotal. It has never had issues immediately (within the first 10 min). I also checked the battery, connections and all. I have a volt meter that read 12.6 and my bike has never had issues starting. The connections were very clean and the battery is a fairly new Xtreme AGM battery. It appear that the vent covers were slightly bulging but when I took them off nothing appeared to be damaged and the vent covers went right back on. There was a very small amount of leakage (white line of crystalized sulfate) from one of the vent caps but nothing that looked to be a real issue. I looked at the throttle body and although it has a small amount of carbon build up near the valves nothing appears to be too dirty or damaged. I looked over as much as the bike that a could and didn't see any glaring issues but I am extremely new to bikes and automobile mechanics. Im a quick study but only in the basic stages of understanding my bike. I have a power commander 3 that appears to be functioning correctly but how would I know. Any suggestions anyone? Your help is much appreciated.

[pete]

Welcome to the forum from Perth Aus :)

Has the bike any modifications to the engine apart from the Power Commander ?
Once the members have a clearer picture of your bike, they should be able to point you in the right direction.
Cheers, Pete.

[ldhthept]

Clean throttle bodies real good with a tooth brush and Seafoam or other throttle body cleaner. Add Seafoam to full gas tank as well. Then take her out and bounce it off the rev limiter a time or three in first/second gear. That should clean off some of carbon build up. See if that helps if not I would look at fuel pressure/pump as well as coolant/water pump. Good luck.

[MAS Tequila]

Are you sure the engine is stuttering?

Check your clutch spring.

[Mystussnake]

Thanks everyone for replying so quickly. I will try to answer each question to the best of my knowledge. I don't think the bike has any mods other than the power commander. I will clean the throttle body next. I have already ran a can of seafoam through the gas tank but I will brush out the throttle body as well using seafoam. I don't know how to look at the fuel pump that may be more then Im capable of at this point. That goes for the coolant pump as well. I don't have any coolant leaks but that is all I know. Im not sure the engine is stuttering as I don't have any stuttering engines to compare it to. The previous owner and I are going to take a ride this weekend so maybe he will know if it is stuttering or not. Its interesting that you mentioned the clutch spring as I pulled the clutch in today (without shifting gears) while it was "stuttering" and it stopped stuttering for about 15-20 minutes. How do I check my clutch spring? I also forgot to mention that when the bike is acting up it also vibrates much more then normal. When this bike is running right it purrs but when it acts up the muffler sounds deeper (almost a growl) the bike vibrates and sometimes there is backfire when switching gears, just one pop right as Im switching from 1st to scond then from second to third. I have yet to hear it do this from 3rd to 4th or 4th to 5th. My bike does not back fire at all unless it is acting up.

[Mystussnake]

I also wanted to mention that when the bike is acting up it significantly backfires upon deceleration.

[Mystussnake]

Something else I wanted to mention is that normally to shift to neutral I have to pull up the shift lever when in first but sometimes my bike is going into neutral while downshifting. Why is that happening?

[DragonLady58]

Well, its probably a fuel delivery problem, the 1500/1600s are Identical except for the crank stroke....
I would clean the throttle body as told, also, run a couple cans of seafoam thru the system to clean the injectors/pump....and do a baseline tuneup with some iridium plugs. A stutter in the drive train like clutch slip, or a engine miss? Check your clutch spring, as per MAS.

If its still acting up, check your pump pressure and the pump quantity....
Does your bike have a Aftermarket exhaust? Aircleaner? If you have leaking exhaust gaskets, that can cause backfiring, also the red valves in your exhaust system. If you have coasters, a gasket could be leaking....
Wait till your shop fixes your problem, especially if your not familiar with your bike and your not mechanically inclined.
Since you have a power commander, and if there are no other mods, this could be a problem, also.

One of the best things to do to these bikes is to have it desmogged, install coasters, add exhausts, intake,.....your bike will run 75% better, will have more power, will be alot more peppier, better gas mileage and will run cooler....

[Mystussnake]

Thanks a lot Dragonlady, I will do what I am capable of doing unless I find someone else to supervise me. At the very least I can let the shop know what I have learned from here and my personal experience with the bike. I spoke to the previous owner today and he said he never modified it. He bought it in 2010 with about 7,000 miles on it. He has never had to repair the bike, only make sure that preventative maintenance was preformed in a timely fashion. Im thinking the issue has to do with the clutch but I have to reproduce the effect that occurred last night a few times to confirm. When I pulled the clutch in during the issue then let it out, without shifting gears, the issue cleared up for a short time (15-20 min) The issue also seems to be worse under load when I am carrying a passenger. Before it would take the bike a while to have an issue while riding but when I have a passenger it happened within the first five minutes.

[Mystussnake]

The first time the issue occurred it lasted about a week then cleared up for another 2 weeks or so. The issue seems to be somewhat intermittent.

[Guzzi]

Believe it or not, this could be a battery issue. Vulcan 1500/1600 require a strong battery to run the EFI system properly.
Your current battery can be capable of starting the bike easily, but might be going bad. Rough running engines have been fixed with a simple battery replacement.
It happens so frequently that on the Kawasaki Vulcan Delphi forums battery swaps fix everything.

[jesse]

What kind of oil? Automotive oil has friction modifiers, which will affect clutch.

[Mystussnake]

Thanks Guzzi, I may actually swap out the battery this weekend just to try. I thought about that myself although when I rode at night and it was acting up the headlight did not flicker or change brightness so that confused me a bit. It is still an easy try so I probably will. The oil that goes into this bike is synthetic but I don't know the brand. The previous owner always had it serviced instead of doing any of this himself so he know very little about the bike. Thanks again for eveybodys help, you guys are great!

[pete]

If you don't have any intake mods, I would disconnect the Power Commander, adjust idle revs to spec if needed, and go for a ride. If problem persists, then at least it eliminates the fuel unit.
Cheers, Pete.

[Guzzi]

Originally Posted by Mystussnake

Thanks Guzzi, I may actually swap out the battery this weekend just to try. I thought about that myself although when I rode at night and it was acting up the headlight did not flicker or change brightness so that confused me a bit. It is still an easy try so I probably will. The oil that goes into this bike is synthetic but I don't know the brand. The previous owner always had it serviced instead of doing any of this himself so he know very little about the bike. Thanks again for eveybodys help, you guys are great!

Check you connections for corrosion and insure the connections are tight before replacing the battery.