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Discussion Starter #1
OK, now that I have your attention, I have a severe problem with my new VN750 with 286 miles on it. I'll try to explain. I started it up for a long ride this morning, (42 degrees) & after a good warmup, I took off. It ran like a Swiss watch for about 25 miles. I came up to my first stop at a four way, & it died. I applied some throttle & took off again. I pulled into a Wesco fuel stop & it died again. I then smelled gas. I restarted & headed out again. I got to my destination, & I had to turn the idle up to keep it running & it didn't want to idle very good. It sat there for about a half hour at my friends home. I started for home & things really went south. At highway speeds at about 50--60 miles per hour, it purrs along great, but now when I come up to a traffic light, it wants to idle at 4000 to 4500 RPM's! Sometimes it will just sit there in neutral racing at 4000 + and then sometimes it will slowly idle down to 1000 rpm's.

I pulled it into the garage this afternoon.....pulled the fuel tank, checked the tank vent, made sure the vent hose in the right ear was not pushed in too far & checked all of the hoses & fittings that I could get to. Everything looked OK.

I took it back out for another spin, & no better. When I shift gears, when I close the throttle, it speeds up between shifts (to 4500 rpm's). I came back home, & when I came into the drive, it wouldn't come back down to under 4500 rpm's! I reached down & turned the throttle stop several turns out & it idled down & quit. I then turned it in until I got a nice 1100 rpm idle, blipped the throttle a few times, & it sat there & idled fine. Now here is the kicker.......I then twisted the throttle up to 6000 & it wouldn't come down past 4200 rpm's. While it was racing at 4200, I checked the throttle stop & it was back against the stop screw. The choke is also closed & has a small amount of free play. The throttle cables also have a bit of free play.

It just started doing this crap today. I know it is under warranty, but I would like to find the problem myself as it is a pain to take it back to my dealer which is 60 miles away.

It also stumbles & misses a bit when taking off when I can get it idled down. It then smoothes out after 2500 RPM's or so.

I know for a fact that it is getting too much fuel at low speed. Why, I don't know. It does blow out a small amount of dark smoke when I grab a handfull of throttle, & the exhaust pipes are blacker than a black cats hiney!

I already had to take this bike back to dealer at 91 miles for a rear trans seal replacement! This is my ninth bike & first KAW, & probably my last.

Sorry this post is so long, but I wanted to give all of the info I could.
Any ideas?

Tcat
 

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Geek
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Both pipes have black smoke ? Check the spark plugs. When mine was brand new I had some problems and the dealer replaced the plugs and all the problems went away.
 

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rnewell said:
Stuck float ?
That's kinda what it sounds like to me.
One old trick is to tap the carb bowls with something like a wooden handle from a small hammer. Don't smack it hard, just tap it a couple times.
Even if that does smooth things out, it wouldn't hurt to have a competent dealer look at it.
With less than 300 miles, I can see that some things may still need tweaked a little. Don't let this dicourage ya from the Vulcan just yet. Some more miles on it will get everything where it needs to be.
 

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Discussion Starter #5
Did that

On my way back home, I stopped at another friends house. He has a 2004 VN750 with about 4500 miles on it. I did ask him for a plastic hammer, & I then started it up......twisted the throttle up high, & it came back down to about 4200 rpms. I then started tapping the carbs one at a time & it just sat there racing at 4200 r's. It didn't change a thing. I had to shut it down at that high rpm. I then restarted it & it idled at 1100 or so. ?????????? It was a real bitc* coming up to a stoplight with the engine racing while waiting forever for the light to change! :mad:

It act's like the carb slide/diaphram unit is hanging up, & the needle is still up out of the tube. I do know for a fact that the round throttle plate is coming all the way back, but not sure if the slide assy with needle is back down or not.

I just went back out & pulled the rubber air boots off of the end of the carbs. I reached in & pushed the slide & needle up & down on both carbs, & there is lots of free play & not binding. Maybe a vacuum problem, holding the slide up after the throttle is closed??????????????
 

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have you checked to make sure throttle cables are not sticking? maybe the dealer forgot to lube them. there has to be something up with the throttle linkage, cause it needs the added air to get to 4200 rpms, it cant do that on a closed throttle. On the otherhand, the way our carbs work, all the throttle does is release pressure, so as you said it could be vacume related, since that is what actually opens the throttle.
 

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Once Banned
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Having not had the carbs out, I've gotta ask - you mean to say that the throttle doesn't open the butterflies?
 

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Discussion Starter #8
Thanks for the replies

Hi guys.......The best way I can explain this problem is.....when the bike idles at the proper speed, at 1100 rpm's, the metal carb stop bracket is all the way back & touching the idle stop screw. Also when the bike is running at the high idle speed (4200 or so) it is ALSO back against the idle stop screw. Either way, the metal bracket is touching the stop screw.

The way the carbs work.......is it possible that one or both of the carb butterflies is sticking open even if the bracket is all the way back & touching the stop screw? I thought that the buttereflies were tied to the metal bracket that touches the idle stop screw?

One more note.....when the bike decides to idle back up to the high rpm's....when it does this crap, it IS running very smooth at that high idle, like both carbs have a problem, not just one. ???????

As one of you guys stated above, when it idles fast, it does have to get it's air from somewhere, but as I stated above, the bracket is all the way back touching the stop screw at 1100 or 4500 rpm's! Again, dosen't that mean that the butterflies have to be closed also when the bracket is touching the stop screw????? Hmmmmm

Thanks for your great replies. I am getting very frustrated with this new bike, but I do want to fix it. Our riding time will be coming to an end soon here in Michigan, & I don't want to put it away broke!

Please keep any ideas coming so I can fix it & not have to haul it back to the dealer again.

Tcat
 

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Search Goddess
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Based on past experiences from others with new bikes.. let me pass this along to you..

It is not uncommon for bits of a gel like substance to show up in the carbs on a brand new bike. Doesn't happen to all, but I have heard of at least a half dozen or so new bikes where they did take it back to the dealer and they pulled crud out of the carb. It's part of break-in cleaning process getting all the loose gaskets pieces etc out of the system.

My suggestion.. Let the dealer to the tedious carb work under warranty.
 

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cegodsey said:
Having not had the carbs out, I've gotta ask - you mean to say that the throttle doesn't open the butterflies?
.....nope, first, we have slides, not butterflies....second, the diaphram opens the slide from the vacume of the engine, and all the throttle does is release the pressure to close. that is how all CV carbs work. This is done to keep the right amount of air at all rpms and altitudes.

i would follow dianna's advice, let the dealer do it... its still under its break in.
 

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Once Banned
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I'm gonna have to pull a carb to check this out. No! Wait! After the tensioner debacle, it would be best that I buy an old carb and take it apart.
 

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Discussion Starter #12 (Edited)
Big update on problem!

Well boys & girls.........I'm not going to get into whether we have only butterflies or slides.............but we do have both! The throttle cables are connected to both carb butterflies (throttle plates etc......call em what you want) & the slides are vacuum controlled, with tapered needle. We also have fixed high speed jets & low speed (pilot) jets. We also have...............Hmmmm, I wasn't going to get into that...........

UPDATE: Last night, after my horrible Sunday ride as stated earlier, I pulled the bike into the shop. I poured about five oz. of "Seafoam" into the tank along with six oz. of "Polaris" carbon clean. (similar product). I took the bike back out for a five mile ride. It still ran terrible with high idle & bad fuel smell coming out of the pipes. (black smoke also). That was last night. Tonight after work, I poured another eight oz of Seafoam into the tank, (no smart comments) filled it up with 92 octane, & started it up. It spit & sputtered a bit & then started to straighten out. It is cold here, so I let it idle for about 5 or 6 minutes before taking off. I had only gone a mile or two before I knew something had changed for the good. I just got back a few minutes ago after a 77 mile ride! The bike runs like a fine tuned Lamborgini. Idle is at 1100, no more high idle, no more fuel smell, no more black smoke, no bad stumble or sputter when taking off, no quitting............just a fine tuned & running bike! I simply can't believe it! The only thing I did was to put Seafoam & carbon clean in the fuel. ?????????????

Again, the tank & carbs sat for over 24 hours with the above two solvents in them, & tonight with the added 8 oz of Seafoam..........YIPPIE! The bike has not run this good since the day I brought it home. If you go back & look at one of my first posts under transmission/rear end forum, I also mentioned that my bike had quit several times while coming into my drive. It always restarted, but kept quitting & wouldn't idle. This has been going on since it was new.

Tonight I went back down to my buddies house. He called me last night after I got home & told me that when I left his drive, both pipes were belching black smoke. He called me tonight after I got home, & said tonight when I left, it looked & sounded sweet.

I ain't, & I mean ain't........going to say my carb problems are solved, but I think that Dianna is right & the Seafoam & carbon clean additives dissolved something in the carbs & or float bowl. I really think that there was something under the needle & seat assy & the Seafoam ate it! I have never used Seafoam before, but if my baby keeps running like it did tonight, it won't be the last time I use it. :pepper:

Also tonight, I drained the float bowl......restarted the bike....again drained the float bowl & found nothing in the cup.

Thanks everyone.......yes even Cegodsey.......for all of the ideas. I'm keeping my finnnnners crossed..............:motorcycl

Tcat
 

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Regular use of seafoam in the tanl will prevent any other crud build-up too. about 3-4 ounces a couple of times a month..

Glad it got cleaned out for you!
 

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cegodsey said:
I'm gonna have to pull a carb to check this out. No! Wait! After the tensioner debacle, it would be best that I buy an old carb and take it apart.

make it easy on yourself... just take off the carb boot at the carb and you can see the slide there.....
 

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SeaFoam does it again
 

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Hizzo3 said:
make it easy on yourself... just take off the carb boot at the carb and you can see the slide there.....
Or you can just study this diagram:



Tcat, your bike was acting like my KZ1000 (also CV carbs) did a while back when I (can't believe I'm admitting this) left all four main jets loose and they fell into the bottom of the bowls. Bike ran like crap--no worse than crap. Idle was all over the place and the gas smell was strong. Of course gas was pouring out the overflow too as I guess one of the jets or more was keeping the floats from closing off. I came into this thread late so you sound like you already figured out your problems. But as I read through it, I kept thinking something was lodged in your carbs keeping a float open. Glad you got it!

Seafoam is coming up around here alot! It's like tuneup in a can. Awesome stuff. I try to keep track and add 3-4 oz every 1000 miles or so, or every month or when ever I think about it and don't remember doing it lately.
 

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Discussion Starter #18
Still purring like a newborn kitten

Hi everybody.........Tonight after work, I bundled up for the cold weather & took her out again. She is running sweet. (so far). I put about 25 miles on tonight & everything is perfect. To repeat myself, the only thing that I did to get it running great & to put Seafoam .........& a good bunch of it........let it sit over night & now it runs like it should. It is still hard for me to believe that putting that stuff in the tank corrected my problem. You folks have no idea what I was going through with that stupid thing last Sunday. I was ready to push it into our gravel pit behind the barn or run it off a cliff into Lake Michigan which is only a half mile away! (No Cegodsey, not with me on it) Geeeeze O' Pete.............

Like Fergy stated above, there is a lot of "Seafoam" stories here & I guess that it is indeed "Magic"! It still blows my mind though..........If this had not happened to me as it did, after reading some of your Seafoam stories, I would have thought that you guys were a few French fries short of a McDucks Happy meal!

Maybe some of you are....One of you does comes to my feeble mind & it starts with "C" & ends with "Y".............but I am not saying who........

Tcat
 

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Once Banned
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ccspinner? No, that ends in an "r". Um, Carguy80 (eighty)? Choppbobby? Chilly?
 

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Tcat1000 said:
If this had not happened to me as it did, after reading some of your Seafoam stories, I would have thought that you guys were a few French fries short of a McDucks Happy meal!

Maybe some of you are....One of you does comes to my feeble mind & it starts with "C" & ends with "Y".............but I am not saying who........

Tcat
I think he will fit in here nicely !:huddle:
 
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