Kawasaki VN750 Forum banner

Need Help Folks!!!

3K views 35 replies 7 participants last post by  Knifemaker 
#1 ·
I recently relocated my R/R. Also changed to a sealed battery and NGK Iridium plugs.

My bike will not start and I am really getting frustrated. Checked all wires, drained the carb bowls, sprayed carb cleaner up through the port in each carb bowl. I had my carbs rebuilt last year, and since then have been putting 1oz of SeaFoam per gallon of fuel added every other time I fill the tank up. Drove her all summer long, and plan to drive all through the winter (I live in the South so the winters aren't too bad).

I need some suggestions on what to check next... The bike turns over but just doesn't start...

please help me :doh:
 
#5 ·
Dumb question, but would I remove the plug, plug it into the wire, and try cranking?
 
#4 ·
Yup, straight down. It had been in the reserve position for awhile.
 
#6 ·
Yes. Might want to hold the plg with insulated pliers or heavy, dry, gloves like welders use. Ground the plug threads to the case, crank and see if there is spark.
 
#7 ·
With the plug in the plug wire, correct?
 
#9 ·
Will try that tonight...Someone else mentioned removing the petcock and cleaning it and the screen... That was all done about a year ago by me.
 
#11 ·
Checked those before putting them on the other night. All within .03 - .035
 
#12 ·
there are 4 plugs so the gap is not an issue. on the iridium plugs they come pre-gapped so you are not supposed to mess with the gap.

have you tried to mess with the kill switch and possibly by-pass it to make sure that's not the source of your problems?
 
#13 ·
We are talking about the power switch on the throttle handle bar, right? If so, I have had that open before, but not sure how to bypass.
 
#14 · (Edited)
If I understand you correctly...the bike will turn over..the starter is spinning the motor, but it just won't catch?

Are you getting any backfires? Have you tried using some ether-type starting fluid?

If you are sure you are getting a spark...and are sure fuel is flowing to the carbs... the only reason I can think of that the bike is not even trying to catch , even for a moment or two, is that the mixture is just way off somehow.

AFter you try starting the bike...like 10-15 tries, what do the sparkplugs look like?
They should look pretty wet and smell of gas.

Do you have a AGM battery btw?

Are you using the choke to start it?

If you are saying the bike will not even ignite a chamber, even once, and you are possitive you are getting sparks in both jugs...there is something wrong with the air/fuel mix.


So make sure ALL four spark plugs are sparking...as outlined above, pull them one at a time, re-attatch the wire and hold the metal side firmly to the cylnder head with some kind of insulated plier.

A dark garage helps here in seeing the spark, but it should be visible as a bright blue to white flash.

If they seem fine and are producing a good spark, the only thing left is your fuel mixture. Try starting the bike with no choke, with the throttle opened, with it closed, and then try using some starting fluid.

You should get it to turn over , even if just for a moment with the starting fluid.

Most times, if the bike is running lean, you should get at least a backfire. If just too rich, you might have a stuck float, or stuck diaphram.


If your battery is low or undercharged , it might just be too weak of a spark.

If the bike ran fine before, and you have done nothing to it , other than touch the carbs...I would suspect that is where the problem lies. Do make sure that fuel is flowing to the carbs .........

and that is is fresh. You might have water in the tank?
KM
 
#15 ·
If I understand you correctly...the bike will turn over..the starter is spinning the motor, but it just won't catch? That is correct.

Are you getting any backfires? Have you tried using some ether-type starting fluid? It is backfiring like crazy. No, I have not tried starting fluid

If you are sure you are getting a spark...and are sure fuel is flowing to the carbs... the only reason I can think of that the bike is not even trying to catch , even for a moment or two, is that the mixture is just way off somehow. You are talking about the adjustment bolt on each carb that is covered by the lead cover, right?

AFter you try starting the bike...like 10-15 tries, what do the sparkplugs look like?
They should look pretty wet and smell of gas. Have not removed the plugs since installing them Wednesday night

Do you have a AGM battery btw? Yes, brand new

Are you using the choke to start it? Yes, adjusting it from none to full

If you are saying the bike will not even ignite a chamber, even once, and you are possitive you are getting sparks in both jugs...there is something wrong with the air/fuel mix.


So make sure ALL four spark plugs are sparking...as outlined above, pull them one at a time, re-attatch the wire and hold the metal side firmly to the cylnder head with some kind of insulated plier.

A dark garage helps here in seeing the spark, but it should be visible as a bright blue to white flash.

If they seem fine and are producing a good spark, the only thing left is your fuel mixture. Try starting the bike with no choke, with the throttle opened, with it closed, and then try using some starting fluid.

You should get it to turn over , even if just for a moment with the starting fluid.

Most times, if the bike is running lean, by lean that would mean the fuel/air plug(s) are not screwed out enough, right? you should get at least a backfire. If just too rich, you might have a stuck float, or stuck diaphram.


If your battery is low or undercharged , it might just be too weak of a spark. I have the bike on a Battery Tender and the light was green when I tried cranking last night.

If the bike ran fine before, and you have done nothing to it , other than touch the carbs...I would suspect that is where the problem lies. Do make sure that fuel is flowing to the carbs .........

and that is is fresh. You might have water in the tank? I coastered and relocated the r/r a couple of weekends ago. It was running fine then. It really wasn't until the other morning when I went to leave the house that I noticed it was barely trying to crank her. That afternoon I had to have someone jump me off. Was that a mistake to use a car to jump me off?
KM
Please see my responses in bold
 
#16 · (Edited)
Was that a mistake to use a car to jump me off?

If it was running at the time, maybe. Cars charge at a much higher amperage than bikes do, so it is possible to damage a bikes electrical components hooking it up to a running car.

However, you made is sound as though after being jumped started by the car the bike ran fine....so seems like your battery is not charging?

If the bike is back firing, you are not getting enough gas ..the mix is lean.
The screw under the led seal thing makes fine adjustments to the idle circuit , and likely is not the reason your bike will not start. As the "choke" is really a fuel enrichment circuit and should allow the bike to start if lean. My thinking is you have a clog in the idle jet(s), or for some reason the carb is being starved for gas.

You might simply have a stuck float...that is why I suggested checking to see if fuel is flowing to the carb. To do this, open the drain bolts on the float bowls until they stop dripping fuel out. Leave them open and crank the bike. If they start pouring gas out...your fine. If they don't, you have a stuck needle valve.

It is possible of course, that your battery might be bad. There have been reports of new AGM batteries shorting out after just a few weeks of use.

I would try charging the battery and then taking is somewhere to have them test it. I would also suggest to try starting the bike with the choke full on, or with half throttle...or both.

Pick up some starting fluid so at least we can eliminate the spark plugs.

KM
 
#17 ·
Could I simply check the voltage on the battery using a multi-meter?

Dumb question, but where would I spray the starter fluid?
 
#18 ·
You want to not just check the voltage , which you can with a tester, but you want to do a "load test" on the battery, which can be done at most Auto parts shops.


I would either spray right into each airbox opening..(kinda tricky to get at) or pull a spark plug from each jug , spray into the cylnder, replace the plugs and then try to start.

You can only check your charging system on the bike after you get it to run of course.

KM
 
#19 · (Edited)
Thanks for your help... You went above and beyond explaining to me. Hopefully this is not a carb problem again...
 
#20 ·
Just out of curiosity sake. If one of the floats is stuck, that would involved removing the carbs, right? I know if the idle jets are clogged that would definitely mean they would have to come out....

And by jugs you mean take one plug out of each of the V's, right?
 
#21 ·
There is a general check list for problems starting a vehicle.

Other than specific issues related to the particular model..like kill switches, sidestand-clutch cutoff circuits...etc...the list of things to check is pretty short:

1. Fuel. Does the vehicle have fuel...is it getting to the carb/fuel injector?

2. Spark. Are the spark plugs providing a good spark when the starter is
pushed?

3. Intake. Is the air intake somehow blocked or altered?


You go through each one and solve them if any issues. Right now , without a report on your plugs, the first two are still open. Eliminate one and you at least have a direction to proceed in.

KM
 
#22 ·
I put coasters on and put the cork-like plug in the line that lead from the air switch to the air box. I also put the little plug that came with the kit on the right side carb vacuum line where the small line from the air switch was previously.

I also failed to mention that last night I removed both air filters and tried to crank, thinking that it was not getting enough air through those...
 
#28 ·
I plugged the big hose coming from the air switch, then removed the small line from the air switch and put the other plug over the vacuum port on the right carb (as you are sitting on the bike) right beside the air/fuel mixture screw,.
 
#30 ·
Would someone be willing to take a couple of close up pictures of the battery box and all the wires that connect to it? I'm pretty positive I hooked everything back up correctly, but I did notice the ground wire coming from the engine that mounts on the right side of the battery box was loose. Speaking of that side, what is the purpose of the other bolt on the right side of the box? Nothing seems to connect to it...
 
#36 ·
Would someone be willing to take a couple of close up pictures of the battery box and all the wires that connect to it? I'm pretty positive I hooked everything back up correctly, but I did notice the ground wire coming from the engine that mounts on the right side of the battery box was loose. Speaking of that side, what is the purpose of the other bolt on the right side of the box? Nothing seems to connect to it...
My guess is that was your problem all along. The motor is rubber mounted, so the engine ground wire really needs to be secure otherwise you would get aweak , intermitant, or just no spark at all.


KM
 
#35 ·
That is the one I was talking about. There is another bolt beside it that doesn't seem to serve a purpose.

Okay, update... Just for the heck of it, this morning I went out and tried to crank the bike.. It cranked right up... I let it run for about 10 minutes with no issues... Left it off the charger and will try to crank it after awhile...
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top