Kawasaki VN750 Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
Hi... Took a ride this morning and on my way home. I initially noticed a loss in power at 50MPH or so. It cleared up fairly quickly... or so I thought.

I came to a stop sign and when I was starting off from a stop, I was only running (barely) on one cylinder as long as I kept the revs up. Every once in a while, the other cylinder would fire and then quit.

I was close to home and made it there - at least I didn't get stranded. As soon as I stopped, the engine quit and I was unable to restart it - so I wasn't able to figure out which one was giving me the trouble.

After about 5 mins or so, I was able to restart and both cylinders are firing and the engine sounds fine. I didn't take it back out just in case..

Any folks out there have any idea where I should start looking?

Thanks in Advance,,

Bryan
 

·
Uber Member
Joined
·
1,280 Posts
how old is the bike? my first guess would be spark plug wires. check continuity, and verify a strong spark to the front and rear cyl. also check the plugs to see what condition they are in. next on the list would be carb related. there is also a small possiability it could be the charging system, but that is an easy check.
 

·
Registered
Joined
·
699 Posts
If I had to guess I would say it sounds like it could be a coil....not sure if theres a test for that other than checking spark.........anybody know?
 

·
HAWK
Joined
·
2,576 Posts
Also could be a fuel problem, how much is in the tank and have you used Seafoam? That is what my bike does when it starts to run out of gas, one cylender quits first ususlly the front.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #5
Thanks Guys.. The fuel gauge was showing 1/4 left and I thought it was fuel too and when it first happened, I switched to reserve with no luck.
The bike is a '93 - my first gut feel was a coil or plug wires. I'll check there first.

Thanks for the input

Bryan
 

·
Geek
Joined
·
872 Posts
Start it up in the dark, you will be able to see if any of the plug wires are arcing.
 

·
Registered
Joined
·
699 Posts
thats how I found mine....started it up at 4:15 am to go to work.
I had a GS750 with a bad coil..it would fire weak then sometimes good...the bike would actually launch forward on me when it did fire, was a trip riding thru town in traffic lol
 

·
Once Banned
Joined
·
2,125 Posts
If you can figure out which cylinder it is, you can physically swap the coils and see if it is a coil going out. Although it could be a plug wire, we have two per cylinder, so the cylinder wouldn't give out entirely. I think. If swapping the coils doesn't fix the problem, then that leaves the plug wires and the IC igniter. This is assuming that the carbs are ok. Run some seafoam through it if you haven't already. Let it sit overnight with the fuel/seafoam mixture in the carbs.
 

·
and the Adventure Cycle
Joined
·
6,141 Posts
I've had something very similar to what you describe happen to me several times.
It'd happen once during a ride. I'd let it sit for a minute or two, then it'd fire up and run fine and wouldn't happen again for the remainder of a couple hundred mile ride.



Several folks here recommended opening the gas cap after it quit like that and listen for the sound of pressure releasing from the tank. Only problem is, it hasn't done it since I heard of that !?

Wish I could be of more help to ya, 'cause I know how frustrating it is when this happens. :doh:
Only thing I can say for sure, when my Vulcan did it, it always started after letting it sit a little while. :motorcycl

If ya do figure out what's causing your's to do it, please be sure to let us know.:smiley_th
 

·
Registered
Joined
·
227 Posts
A maintenance free battery fixed most of my bikes misfiring.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #12
Finally...

Well, Finally got all of the issues corrected and finally nailed down what the issue was.. Long Story...

Well, I decided to do a mini rebuild over the late winter early spring. Thanks to Cegodsey, I identified that I had a bad front coil.. No biggie since I was planning to correct some of the other issues during the winter.

BTW..This forum was an absolute godsend with all of the tips and history contained here. :notworthy
From replacing Spark Plug Tube Orings, HD Exhaust crush gasket for aftermarket pipes, part numbers for Spark Plug caps and Iridiums, Spline Lube.. this place has a wealth of information.

Anyway, bought new coils all around too and when I started up the bike.. everything was awesome (except the brain farts with things like.. not tightening up coolant hoses). Then... no more than five minutes later.. back to firing on the one cylinder :confused:

So, after testing pick up coils, connections and quite a bit of cussing etc.. today I tried cegodsey's trick again with the old rear coil.. and viola!!!... I had a blowed up brand new coil... Installed the old coil and off I went :motorcycl

I hope I can contribute to the forum with my new found experience...

Now it's time for a Cigar and a Beer :beerchug:
 

·
Registered
Joined
·
415 Posts
Let her warm up. See if it is heat related, if so I would think Coil or IC Igniter as previously suggested. Again if you can figure out which Jugis giving you the trouble switch the coils see if it follows the coil. Of course this all assumes you have someone to follow you with a trailer or pickup truck just in case!
 
1 - 13 of 13 Posts
Top