My SJ Won't Go BRAAAAAP Part 2

SJ/XPBri

Just SJBri = no more XP
Location
Northern, NJ
Sorry for trying to pick everyones brain on why my ski has issues. There are no shops anywhere near me that have a clue about a modded ski, otherwise I'd bring it to them. Now for the "No Braap" condition:
Ski ran fine after I installed the analog total loss (I just needed to fatten up the low end)
The ski now will run fine for about 3 minutes, then starts "surging" It accelerates like a bat outta hell, then falls flat on it's face. It's 100% an ignition problem.
I pressure tested the motor, checked the carb, compression, every electrical connection including the plug wires (trimmed them).
I'm hoping that it's the coil, but do not know if these symptoms could even be caused by the coil. I only found 1 shop with the coil in my area, it's going to cost me $120.00 (I know I'm getting robbed) Shoud I look at something else, or buy the coil?
Thanks,
Bri
 

Watty

Random Performance
Location
Australia
Factory yamaha coils are very reliable, and rarely go bad. The fact that it works ok for 3 minutes tells me it's something else. Do you find it does it after the engine reaches a certain operating temperature, or under certain loads?

Something like this is causing intermittent failure. Problems like this are generally heat related, not saying that anything is getting too hot or anything, but something is triggering the fault.
 

SJ/XPBri

Just SJBri = no more XP
Location
Northern, NJ
I agree that it's heat related, the problem is I can't figure what the heat issue could be. The MSD Brain is nowhere near anything hot, the carb is nice and cool (no vapor lock), I can't see the start/stop switch being the cause (I've tested continuity- no shorts before or after the ski warms up). So I'm now running out of things to check. So I've decided to blame the coil.
This truely sucks because I have a week of vacation at the lake starting this weekend. For the love of God- I do not want to ride the sea-doo.
Thanks,
Bri
 

djkorn1

kidkornfilms
Site Supporter
Location
Cleveland Ohio
Pipe coupler leaking? You could be sucking in your own exhaust...That would be the 3 minutes before it ran out of air.

Try running it with the hood off and take a look....
 

SJ/XPBri

Just SJBri = no more XP
Location
Northern, NJ
I forget to mention, the cylinders do get fairly warm to the touch, which suprised me because I'm running dual cooling- 1 circuit for the pipe, the other for the motor. The lake water is around 78 degrees, and outside temp was around 95.
Bri
 

SJ/XPBri

Just SJBri = no more XP
Location
Northern, NJ
djkorn1 said:
Pipe coupler leaking? You could be sucking in your own exhaust...That would be the 3 minutes before it ran out of air.

Try running it with the hood off and take a look....
Unfortunately the coupler is brand new, I also checked it- no leaks :banghead:
Thanks-and keep the ideas coming :biggrin: ,
Bri
 

Matt_E

steals hub caps from cars
Site Supporter
Location
at peace
My old analog total loss used to die intermittenly. Never did figure out what was wrong with it.
 

SJ/XPBri

Just SJBri = no more XP
Location
Northern, NJ
Thanks Guys,
I'll buy the coil tommorow and hopefully all will work as it should. I'll post what happens. If not I'm still looking for a TL brain.
Bri
 
my 94 would work for about 5 mins, and then it would break down like i was running on 1 cylinder, ski would start and idle fine, but every time you went to accerate it would just spit and cough, turned out to be the coil, replaced the coil, and it was fine, haven't had any trouble since.
 

SJ/XPBri

Just SJBri = no more XP
Location
Northern, NJ
Just an update, It was 100% the damn coil. The worst part about it, the coil still OHM's within specification. Put the new coil in, and the ski rips :biggthumpup:
Thanks,
Bri
 
Top Bottom