Engine problems...need help - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 21 (permalink) Old 11-25-2006, 06:00 PM Thread Starter
 
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Engine problems...need help

I am currently trying to revive a 94 750 that has been parked for 4 years. So far, flushed cooling system, changed oil and filter, cleaned air filters, spark plugs and caps, new westco battery. All plugs are sparking, compression is very good.

Existing problems are: possible problem with the choke cable mentioned by previous owner, fuel valve on bottom of tank flows even with no suction on it. small radiator hose leak...

Main problem...engine starts, idle well at 1200/1500 rpm, although the rpms seem to rise and fall every few seconds (another one to sort out). It runs like this for about 5 to 7 minutes and then dies out. After this, it will start, but will only run for about 5 seconds. During both of these runs, I have to leave the choke all the way down, and if i try to give it any gas, it dies. I plan on rebuilding the fuel valve and have a new choke cable on order. Any other ideas would be appreciated. Do I need to mess with the mixture any? thanks in advance for any help.

Travis
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post #2 of 21 (permalink) Old 11-25-2006, 06:33 PM
 
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add seafoam...sitting for that long I am sure that the fuel has gunked up in those carbs..you might want to fill the bowls with it and leave it sit and clean for a while then drain and try again...but definetely add it to the tank also
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post #3 of 21 (permalink) Old 11-25-2006, 06:35 PM
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If it has been sitting for 4 years have you cleaned the carbs? Sounds like a fuel issue.
How is the inside of the tank looking? Might be rust or junk in the takn.
Have you tried Seafoam? It is a wonderful gas cleaner and stabiliser. Don't use Stable.
You may be picking up junk off the bottom of the boals or floats sticking/ getting plugged.
I would try draining the carbs into a container and see what you get out of them.

Chad Falstad "Hawk"
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post #4 of 21 (permalink) Old 11-26-2006, 05:47 PM
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I agree with both of the above. Drain the float bowls and see what comes out. I'd also squirt some Seafoam in the bowls and let it soak overnight at least and treat the gas in the tank. If any gas was left in the tank over the last 4 years, chances are the tank is rusty and the fuel has gone bad. Mine sat for 4 years as well and the gad smelled bad when I got the tank open again. It was also very rusted. I'd at least pull the tank and drain the gas out and fill with fresh. However, it the tank has major rust, flakes will still get into the fuel and wreak havoc with your engine.

Jim W
93 VN 750 "Ursula"
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post #5 of 21 (permalink) Old 11-26-2006, 06:01 PM Thread Starter
 
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carbs have been taken off and cleaned, tank has been flushed. No rust in the tank..filled with fresh gas and very strong seafoam mix for several days (off the bike) and drained, refilled with fresh gas and correct seafoam mix. I also discovered during one run a little exhaust smoke coming from front header..must be a small leak there too. Will adjusting the mixture possibly help with this, if so, what is reccomended? I also noticed what seems to be a noise coming from the right side (while on the bike), possible chain noise. Oh boy, what did i get myself into....
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post #6 of 21 (permalink) Old 11-26-2006, 06:57 PM
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Make sure the vent hose that goes into the back of the right air filter isn't plugged. Snip the hose on an angle so it doesn't bottom out in the filter housing.

Ron from Jersey
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post #7 of 21 (permalink) Old 11-26-2006, 08:54 PM
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Quote:
Originally Posted by tdhallum
I also discovered during one run a little exhaust smoke coming from front header..must be a small leak there too. Will adjusting the mixture possibly help with this, if so, what is reccomended? I also noticed what seems to be a noise coming from the right side (while on the bike), possible chain noise. Oh boy, what did i get myself into....
As for the exhaust leak, that could cause it to not run quite right. Might just be loose bolts, but could be bad gasket. I believe alot of people here have used Harley exhaust crush gaskets with best results.
The chain noise, if it sounds alot like the rattling of a spray paint can, it's most likely the ACCT (auto cam chain tensioner)
There's a post HERE for doing the 'Grambo Trick' to quiet them down. Usually that's just a band-aid fix though and the spings probably need replaced.
In which case, check out THIS post about replacing those.
Which are available HERE.
And last, but not least, TOC manunfaturing ACCT rebuild instruction, HERE.


AKA: Tim & 'The Adventure Cycle' VROC #24567, NEVROC, SteelCity VROC


"When life throws you curves,
Aim for the apex."

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post #8 of 21 (permalink) Old 11-26-2006, 10:39 PM
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Also might want to check for vacuum leak. Make sure you are not sucking gas into the vac hose on the fuel petcock. Take a propane torch cylinder and just crack the valve until a little propane is flowing (unlit). Move the torch tip around the carb bases and each vacuum line. If you have a leak the RPM's will increase noticeably. On a bike you have to take extra care not to pull the propane in through air cleaners and get a false indication. If you don't have propane use WD-40 with the little spray wand it will give the same indications. DO NOT use MAPP gas. If you have a propane torch with a screw off mixing tip put a little fuel line on it and you can localize the leak area better. When I "wrenched" for a livin this was the quickest way to find a leak on a car.

Rckmtn
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post #9 of 21 (permalink) Old 11-27-2006, 10:43 AM Thread Starter
 
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rckmtn, i have a feeling fuel is coming in through the vacuum line on the petcock, a rebuild is in order. I'll pick up some new crush gaskets (hopefully along with a set of V&H's !!). I'll also have to check out the cam tensioner chain. hyperbuzzin, thanks for the tips. I planned on this being a wintertime project, but was hoping I wouldn't have to open up the engine.....we'll see how it goes. I'll keep everyone posted of the progress and try to get some pictures up....
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post #10 of 21 (permalink) Old 11-27-2006, 11:17 AM
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I used the HD crush gaskets - they're pretty decent, and not prohibitively expensive. Buy a couple of pair while you're at it, though - always good to have an extra set on hand.

Also, after the seafoam treatment, were you still getting a change in the rpms at idle? A couple of us were reporting variable rpms, but were able to clear it up with a carb sync. That can be a cheap fix, too (see this link http://www.powerchutes.com/manometer.asp).

C
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