MSD TL problem...

[jeckert]

I think this is TL related. I have a TL system that I bought new about 1 year ago. There is about 20-25 hrs on it so far and I am having some issues. The ski starts out reving up all the way w/ no problems and then looses RPMS or breaks up. The problem is intermittent (it seems fine for 10 secs and the next 10 it breaks up). Last summer there were no problems, and I replaced one of the triggers yesterday. It's difficult to diagnose because it's an intermittent problem and I'm hoping that I will not have to continue to throw parts at it!


Any ideas?

Thanks for your help!!!
Joe

 

[Matt_E]

What's your air gap between trigger and flywheel?

 

[jeckert]

not sure...do you think that they might be to far away? and at higher revs it's missing the signal?

thanks

 

[Watty]

Make sure everything is earthed properly....

 

[Waternut]

If it's missing more at high rpms then your gap is too large...

To clarify: By earthing everything he means connect everything to the negative size of the battery...not ground it like I originally thought.

 

[Matt_E]

not sure...do you think that they might be to far away? and at higher revs it's missing the signal?

thanks

Who installed the TL? The gap should have been set through proper shimming of the triggers at installation time.
If that wasn't done then, it must be done now.

 

[Matt_E]

If it's missing more at high rpms then your gap is too large...

To clarify: By earthing everything he means connect everything to the negative size of the battery...not ground it like I originally thought.

Same thing on a ski.
Negative = ground.

 

[crammit442]

Sounds simple, but change plugs if you haven't.

 

[jeckert]

Thanks for the input guys!

I changed the plugs the other day and it still happens and the shimming checked out ok. Actually, the other day when we replaced one of the triggers we held the trigger right up on the magnet and it fired fine then we tried it again it did not fire at all...kind of weird.

The neg. on the battery is extended out to the mounting plate and everything is connected to this ground except for the coils which are connected to the flywheel cover.

I am going to try another battery just to rule out the possibility of the battery.

 

[Waternut]

Thanks for the input guys!

I changed the plugs the other day and it still happens and the shimming checked out ok. Actually, the other day when we replaced one of the triggers we held the trigger right up on the magnet and it fired fine then we tried it again it did not fire at all...kind of weird.

If you don't run the pickup over the trigger fast enough, it won't spark. Not a problem for a running engine but an issue if doing it by hand.

The neg. on the battery is extended out to the mounting plate and everything is connected to this ground except for the coils which are connected to the flywheel cover.

This is why I said mount it to the battery. I ran my TL negative wire to the grounding strap on the starter which is directly hooked up to the negative side of the battery. I fried one coil doing this and when I hooked up the new coil it would only run for 3-4 minutes and crap out and exhibit the same problems I had with the bad coil. Moved the negative wire straight to the battery...all problems were gone.

 

[D-Roc]

i am curious to how there can be any difference to grounding to the motor or grounding to the battery? i also have a main ground from battery to the starter, a ground from the head to a main ground point on the mounting plate and have the coils grounded to the intake manifold. i ohmed the grounding points and always got the same number. do you guys recommend to ground to the battery directly because of the possibility of bad connections/high resistance wires over time that can cause bad ground and more problems?

 

[Waternut]

I don't really know what my deal was...it would seem to be the same since it's connected through the same huge negative battery cable. Maybe I just jogged some wire or something...who knows.

 

[Project Ski]

Sounds like a coil or wire problem to me

 

[D-Roc]

jeckert, my buddies msd is doing pretty much the same shiat. we even switched to channels 2 and 3 and would get spark while testing then put everything back and we fired the ski a couple times but the next day when we went to ride, it was giving intermediate spark again. He baked it for a full day in a "hotbox" and we are going to bench test it this weekend again.

 

[Matt_E]

If you don't run the pickup over the trigger fast enough, it won't spark. Not a problem for a running engine but an issue if doing it by hand.

It doesn't take much. You can move the trigger by the magnet by hand without exerting yourself and see it spark.

This is why I said mount it to the battery. I ran my TL negative wire to the grounding strap on the starter which is directly hooked up to the negative side of the battery. I fried one coil doing this and when I hooked up the new coil it would only run for 3-4 minutes and crap out and exhibit the same problems I had with the bad coil. Moved the negative wire straight to the battery...all problems were gone.

That tells me your grounding between engine and battery is bad.
In a properly grounded motor, engine ground = battery negative.
However, you should always ground the TL to the battery. You're eliminating one mode of failure that way.

i am curious to how there can be any difference to grounding to the motor or grounding to the battery?

There is no difference at all, electrically.

 

[jeckert]

This is why I said mount it to the battery. I ran my TL negative wire to the grounding strap on the starter which is directly hooked up to the negative side of the battery. I fried one coil doing this and when I hooked up the new coil it would only run for 3-4 minutes and crap out and exhibit the same problems I had with the bad coil. Moved the negative wire straight to the battery...all problems were gone.

How long were you able to run the TL with the bad ground before this problem first popped up? I ran 30 gals of gas through my ski before this first happened. I am confused how the TL could run fine for 30 gal of gas w/out a problem and then the possibly the ground being bad. Shouldn't it of had problems from the get go?

I'm surprised how much of a diff the ground location can make. I ran the coil ground to the battery and same thing occurred, but lost 20 mins. I made spark only for 5 mins. this time, rather than 25 or 30mins in the previous 2 rides. However, I have not had a chance to run the ground from the TL to the battery (the cable is to short)...guess I need to do that.

 

[Waternut]

I ran my ski for about 4-5 hours before it crapped the bed and I fried my coil. My guess is it takes some time to completely destroy the coil. I honestly can't imagine that the grounding wire between the engine and battery is that bad or the starter would act funny. Then again, I don't see how rerouting a small 14 ga. wire from the TL ground through a 18 inch length of 6 ga. wire could cause a problem either but it certainly did.

I'll have to look into change my grounding wire soon.

 

[D-Roc]

did you happen to try a different set of plug wires? perhaps a buddy has a set you could swap just to try?

 

[Lakeman]

How old is your battery? A week battery could cause this problem. old spark plugs is anther item to check. If it ran fine last year and now you have issues then your gap on on your pick ups would have been an issue last year don't you think. Unless the screws have vibrated loose and the gap has changed, then I would think you shouldn't spend to much time looking at that issue. Check all your wires for loose connection. Check all your ground wires. I had my system wire by John at Jet ski solutions and he had me run a ground wire from the coils to the eninge cases. Does your system have this ground wire? If not install it.
Dale