Only firing on 2 Cylinders

[Wrecka]

I own a 92 full power Vmax.
Last weekend i fitted a Scorpio bike alarm , run a series of tests after installation one being trying to start the bike with the alarm armed.
When i did this and turned the ignition and kill switch off the starter stayed engaged and by the time i could unhook the battery it was run flat.
Next day i bought a new battery and while taking the old one out i accidently shorted the screw driver across the solenoid , Got the battery change done , put it all back together , wound over fine but was hard to start , when it did it's obviously only firing on 2 cylinders.
Im reasonably sure that i have stuffed something electric but not sure which part , anyone got any suggestions as to where i should look first ?
Thanks
Sean

 

[[email protected]]

First thing I would do is check the fuses and disconnect the alarm for testing purposes.

 

[SpecOps13]

No clues other than those mentioned but welcome to the forum.

 

[one2dmax]

Change the spark plugs just in case.

 

[Wrecka]

Thanks for the welcome.
Tried running the bike without the alarm connected, was one of the first things i tried and that made no difference.
The motor ran perfectly up until the afore mentioned instillation and shorting of the solenoid so i really dont see there being a chance of spark plug failure , im guessing ICU so i will take that out and get someone to check it for me.

 

[Wrecka]

Just finished putting a secondhand control unit ( one that is in a bracket in front of the airbox ) and still no luck , still running on what sounds like 2 cylinders

 

[06VMAXIMUS]

Possible you fried 2 of the coils? I think its possible to test the coils with a voltmeter, and you should also be able to test for power going into each coil as well. Just a thought.

 

[06VMAXIMUS]

I would pull all the plugs and ground them on the engine. Crank engine over and see that you are getting good strong spark to each cylinder. This will help isolate whats good and whats not.

 

[Wrecka]

Thanks mate, will do the check for spark next .

I read a post awhile back ( not sure what sight ) and it said sometimes when the vmax battery gets low it can weld shut a contact that causes the startor to stay engaged , i cant for the life of me find that article or website , but does anyone know what the technical name is for the parts that weld so i can get into them and have a look ?

 

[alorio1]

You could have the back two coil connectors crossed. Switch them around and do a restart, let the engine run for about 20 seconds and feel the header pipes to see which ones are hot/warm and this will tell you which cylinders are firing.

 

[m2trooper]

if by chance it would be the rear two cylinders since you had to remove the two coils to install the battery ,, you may have pulled the spark plug wires out of the coils a bit.. check the connection from the coils to the wires..

 

[Wrecka]

Im over it already , bike mechanic came over yesterday and picked it up

 

[Rand-5107]

Let us know what it was when you find out. Knowledge is power and we all love power.

 

[Wrecka]

Let us know what it was when you find out. Knowledge is power and we all love power.

Will definitely do that , might make someones fault finding that much easier

 

[GREEN light BLITZ]

Must have arced your battery to one of the carb chain circuits...that's GOTTA be the issue.

 

[Wrecka]

Got the bike back today running like a dream , mechanic said he couldnt find any one particular thing that could of caused the problem , he changed the plugs and checked all the connectors , changed the leads and did a full service and now it's running sweet , strange but true.........

 

[Rand-5107]

Thanks a lot for the update. It's to bad he couldn't figure it out either. But at least he was abel to fix what ever it was.

 

[SpecOps13]

I've fixed a lot of problems that defy explanation. That seems to be a strange fact about VMax's... Great that it's running right....

 

[Rusty McNeil]

If synch isn't just right and idle is low it's pretty common to idle on two cylinders. should go away when you crack the throttle tho'

I've fixed the same problem your describing tho, missing at speed, a coiuple of times by replacing the plugs and wires, even tho they all "looked" ok......

 

[SvenDGAF]

if by chance it would be the rear two cylinders since you had to remove the two coils to install the battery ,, you may have pulled the spark plug wires out of the coils a bit.. check the connection from the coils to the wires..

It's gotta be that I reckon. Esp as the mechanic changed the leads, thereby making a new, good, connection at those coils.