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Registered Badass
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Discussion Starter #1
The odd part is it runs fine cold. Once she warms up I have all kinds of problems between 2K and 5K RPMs. The hotter the bike the worse it gets. I'm not talking overheating type temperatures. Just normal running temp.. stalls and pops.. tac goes jumping up and down. If I get it over 5K, runs just fine. Below 2K is fine. Idle is smooth.

I'm assuming I've got a mid-range jet clogged but why the change with temp? I can pull over and sit for awhile and it'll run fine again for a bit..

Any ideas?
 

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Search Goddess
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2,002 Posts
Check the hose in the right ear.. If there isn't one there and you still have the stock air filters, it needs to be routed through the little grooves. If there is one there, make sure it isn't bottomed out against the case. Cutting the tip at 45 degree prevents that happening again.
When you are running you need spark, fuel and air. If the air is cut off (also check for the hose being kinked or pinched) the bike will sputter since it is actually gasping for air.
 

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Registered Badass
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102 Posts
Discussion Starter #3
Checked. Air filters are fine as well.
There seemed to be a lot of oil on the carbs. Not sure if that's a clue. How would oil get there? Actually I'm not 100% sure it was even oil. I cleaned up everything and will monitor it.
Bike could use an oil change but if it's leaking I don't want to waste my time/money.
 

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The oil in the filters is there to catch the dirt that comes in. The oil is there on purpose and is not an oil leak or a bad thing. When you clean the air filters you will get to re oil them as well.
If the vent hose is kinked or plugged, it can cause the symptoms you are describing. The change in performance from cold to warm can be caused by the heat causing the hose to expand or elongate and cause the pinch off/plugging of the hose. Follow Dianna's advice and check the hose and let us know so that if the vent hose is the problem, we know it's solved. If not, there are some other avenues you might try such as Sea Foam.
 

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Registered Badass
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Discussion Starter #5
I've been running Seafoam for a couple weeks already. After checking everything else I went to pulled the carbs. The brass pieces that the float pins hold onto had a lot of crud on them. I gave each jet several blasts. Bike seems to be running okay but I have to reset the idle and maybe the air mix screws. This is complicated by the fact my idle adjust bolt snapped a month ago.
I'm sure I'll have it under control soon.
 

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Uber Member
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well i wish ya luck. if you keep having carb trouble, you may wanna get an ebay replacement, although it looks like you have made it into the home strech. one thing that i suggest that doesnt look like you have done is the seafoam soak. its better then the blasts you were giving.

over a weekend or so, drain the bowls, fill with a 100% seafoam, and run for just a few seconds if she will start, if not just crank for a few to get the seafoam pulled into the jets. let it sit over night. this will clear out any and all gunk left over since it sounds like you had quite a bit, since the pins and innards are the last thing to gunk up. afterwards, drain and fill back with gas, and start like normal (may take a few cranks)
 

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and the Adventure Cycle
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The oil in the filters is there to catch the dirt that comes in. The oil is there on purpose and is not an oil leak or a bad thing. When you clean the air filters you will get to re oil them as well.
Just wanted to point out that he mentions oil (?) on the carbs, not the filters.

And, if ya do get things running good and are happy with how the carbs are working, replacing the idle screw is an option.
PN 16021-1112, SCREW-THROTTLE STOP
Ron Ayers has it listed for $51.41,
And Bike Bandit for $61.31.
 

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I really wasn't too clear on where he meant the oil was coming from. One never knows exactly how "new" one is to mechanican. :)
If it's on the carbs, it could be coming from the valve cover gasket leaking a bit or it could be someone did the WD 40 test and just left the mess.
Either way, it sounds as if Bean is well on the way to fixing his ride.
 

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Registered Badass
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Discussion Starter #9
Okay so here's the latest..
As I mentioned, Monday last week, I pulled the carbs and gave them a good cleaning.

Once I had the idle set the bike ran great. I was very happy because I had planned on riding to Vegas that weekend. The following couple days I found and fixed a problem with a throttle cable. Didn't do any long/hard riding (just my commute to work, about 7 miles each way), but as far as I could tell she was running fine.

Thursday I changed the oil and replaced the oil filter. Unknowingly at the time I had overfilled the oil.

Friday I start having the same problems again on the way to out meeting place before heading out to Vegas. Bike ran fine above 5K RPMs. Considering it'd be freeway riding the whole trip, and I already had everything booked/paid for.. I continued with the trip.

Everything went as expected. As long as I kept the RPMs above 5K and below 7K (which is were she prefers to run anyway), it was fine. Other then being cold at the end the ride was quite nice until I actually got there and had to deal with traffic lights and such.
Along the way I discovered I had overfilled the oil. My parking lot at home is slanted so the bike is not level which adds some guess work to things like oil changes.
This would explain the oil in and around the carbs I mentioned earlier (although some of that may indeed have been from a WD-40 job :)

So I drained the oil down to Low on the sight glass. Dumped some generic carb "treatment" in the tank (couldn't find SeaFoam anywhere in Vegas). I might have been in my head but there seemed to be some improvement but the bike was still having the same problems. Sunday I road home and noticed I could get above 7K RPMs (I never had the chance to safely test the limit). I kept it around 80mph and got home fine. I then dumped half a can of SeaFoam in the tank.

I've since made one round trip to work and the problems are the same. Fortunately I bought a dry-cell battery (as recommended here) which has made starting the bike as easy as pressing the button, so stalling at lights isn't so nerve wracking when it happens.

Sorry this post is so long. I thought if I wrote it all out someone might pick up on a clue. I believe the oil change had something to do with it. This originally started after a day of maintenance, which included an oil change but also a bunch of other stuff which confused the situation (did too much stuff at once, big no no). I'm quite sure I had overfilled that time as well.
However, with the oil now at Low, and having traveled 300 miles I would have thought any oil left in the carbs would have worked it's way out by now.
Would oil in the carbs even be a problem to begin with? Perhaps it's something completely different that I'm missing..
 

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Registered Badass
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Discussion Starter #10
Sorry to double post. I just realized my fuel lines to my carbs to the petcock are backwards. The rear carb's line should go to th front connection on tghe petcock etc. Does this really matter at all? The manual says this is to keep the hoses from flexing or something to that effect. I've already cut mine down so that they're okay as they are. I'm just not sure if it'd effect anything like that.

I've never synced my carbs and have had them off three times. So now I'm looking into that as a possible issue.. Much reading to do..
 

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It shouldn't really matter which hose goes to which carb, as long as the vacuum hose i connected properly.

As far as the bike struggling between 2 and 5K, it could be the ignitor box failing. I've had a couple of bikes do the same thing in the past and it turned out to be a faulty ignitor.
 

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Registered Badass
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Discussion Starter #12
hmm I'll take a look. I've replaced it once in the past already although it was with a used part. Maybe I can try the original one if I've still got it. I think it's actually good still (problem turned out to be something else).

I had also replaced my spark wires. I'll check their connections to the coils.

Everything electrical seems okay really but it wouldn't hurt to give everything a look over just to rule those things out.
 

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Discussion Starter #13
Today I was trying to get at the rear coil and thought, "this would be easier if I removed the battery." So off went the seat and what did I find? Both power wires had lose connections! Like I said, I had replaced the battery not long ago with a dry cell. It seems I didn't tighten those terminals down enough. Sadly, I tightened one so much the terminal itself started to bend! Not enough to really harm it but I was shocked that the metal was so soft. This is a Yusa btw.

This gave an amazing improvement. The bike hauls ass again! However, on the way back from my test ride with the engine nice an hot, the problems started again around 4K during hard acceleration.. Not nearly as bad. But enough to squelch my celebration. There must be something else still.

And a quick question: If I've coastered, can I remove the rear vacuum hose and plug that fitting on the carb? Many of the hoses on this bike have seen better days. I'd like to eliminate the use of any of them if possible.
 

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Today I was trying to get at the rear coil and thought, "this would be easier if I removed the battery." So off went the seat and what did I find? Both power wires had lose connections! Like I said, I had replaced the battery not long ago with a dry cell. It seems I didn't tighten those terminals down enough. Sadly, I tightened one so much the terminal itself started to bend! Not enough to really harm it but I was shocked that the metal was so soft. This is a Yusa btw.

This gave an amazing improvement. The bike hauls ass again! However, on the way back from my test ride with the engine nice an hot, the problems started again around 4K during hard acceleration.. Not nearly as bad. But enough to squelch my celebration. There must be something else still.

And a quick question: If I've coastered, can I remove the rear vacuum hose and plug that fitting on the carb? Many of the hoses on this bike have seen better days. I'd like to eliminate the use of any of them if possible.
If you have coastered, you can remove all the hoses and the valve behind the airbox. Need to cap the vacuum port on the right carb (that line gets removed) and plug the air hose into the airbox that fed the valve you just removed.

Any questions, let us know.

Sounds like you are hitting a lean condition. Is the exhaust stock?

Jon
 

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Registered Badass
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Discussion Starter #15
Thanks for the info.
I haven't messed with the exhaust but it seem to have some kinda CA model pipes. Not sure if that effects anything but I'm sure the bike is tuned to work with them.
I believe I have an electrical problem at this point. I've found I can reproduce the problem by leaning the bike left. It acts just how it did when the battery wires were loose. May have to do with the handlebars turning and pulling the engine cutoff wire. I need to experiment more.
I'm not ruling out a carb issue though. Maybe the leaning effects one of the floats..
 

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Discussion Starter #16
Just a quick update.
I went through all the connections I could think of.. Plus to/from Igniter box, regulator, the 3 wires for the alternator, battery terminals again (they were still snug).

The bike had been running great 95% of the time. There was one time when I had rode for about an hour and still had the choke on a bit. I killed it and after awhile the problem started again and continued till I got home (even after choking again). I'm not sure if the choke actually had something to do with it or not. That was before the electrical work and I've yet to see the problem again.

Yesterday I finally plugged the vacuum connection on the right carb. WOW what a difference that made! The bike has much more power and in fact idles too high (at 3100rpm). The hose going to that connection was old and cracked. No doubt other hoses were as well. I'm glad to have the whole mess removed now. Thanks for the help on that.

Anyway, it seems I have this licked. Although I wouldn't be surprised if this problem pops up again (just cause it seems i can't get rid of it). I don't know what else to check if it does.
Oh and the bike no longer has problems when I lean it left/right. So maybe it is 100% finally...
 

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and the Adventure Cycle
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Best of luck with the bike Bean. Sounds like ya have the problem fixed.
Hope all goes well with everything from now on for ya.
 

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If it starts acting funny again, play with the carb breather hose while cruising down an unbusy street. I experienced that my bike wouldn't run right if the hose was in the airbox or facing backwards, but if I faced it forwards outside of the airbox, the bike ran perfect. Kinda weird I know, but it worked for me.
 

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Discussion Starter #19
Well, ten days later and she's still running like a beast! Amazing what it can do now. I'm in love with this bike all over again! I was ready to sell it, now I want to keep it at least another year. If only she looked as good as she runs.. old '94 is showing her age. Still, I can't think of a better way to commute. Getting up for work is much easier knowing I get to ride there :)
 

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Well, ten days later and she's still running like a beast! Amazing what it can do now. I'm in love with this bike all over again! I was ready to sell it, now I want to keep it at least another year. If only she looked as good as she runs.. old '94 is showing her age. Still, I can't think of a better way to commute. Getting up for work is much easier knowing I get to ride there :)
I know what you mean. My '93 runs great, but the engine sure could shine a lot more. Thats really my only sore spot, if there was just a way to get back that shiny engine look....

Jon
 
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