Snowmobile Forum banner

1 - 20 of 33 Posts

·
Registered
Joined
·
27 Posts
Discussion Starter #1
My son was riding to the fish house, and he said the thing just shut off on him. I had noticed in the last couple of days when I rode it that it would partially cut in and out... like from 50% to 100% part. Very subtle, and only for a half-second. And only at low rpms. Wide open, it went like a bat out of... I have tried to start it, it turns over like normal... hard... good compression. It randomly fires.. a little, but won't actually run. I tried drizzling a bit of gas(mix) into the cylinders... normally this is a sure fire start up. Nope. So, I'm thinking because of the suddenness of the stalling, and the non-response to direct fueling, that this would be an electrical problem. Which part? Coil? CDI? is there a more common failure among those? How can I test them?
 

·
Certified Mechanic
Joined
·
56 Posts
Coil is the easiest and cheapest way. Just take the plugs out, keep them in the caps and place the electrode end on the head. Pull it over and watch the plugs. You could have a loose plug wire, a coil is bad, or the stator is crapping out. A dealership should be able to test the stator for you for fairly cheap if you have the sled apart for them. Otherwise you will need to get a repair manual and multimeter to ensure everything is good with that.

A compression test is always a safe bet before spending large sums of money. Each cylinder should be at least 120 psi. If below that the engine may not start or run, or it will every now and then if your lucky. Your scenerio seems to be more electrical to me. Start with the coils and go from there.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #3
OK, so is it possible that when a coil goes bad that there is still some spark? Or is it all or nothing? I tried it again today, and it fires weakly, maybe three or four times.
 

·
Premium Member
Joined
·
5,737 Posts
by pass the tors. i have seen alot of the older exciters have the throttle switch crap out. make sure the throttle cable isnt sticking prior to the test!from there go on through with the testing of the coils, grounds, and the output from the stator.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #8
Update: Got a coil today, when I looked at it, I realized that the one already on the sled is a newer one... bad feeling that it wasn't going to help. Also, one of the mounting bolts refused to come off. Hooked up the "new" coil anyway with the one bolt... same story. Pulled the plugs out, and left them connected to check spark when I pulled it over. Seem to spark as often they should... but spark seemed very small... tiny. Tried drizzling some mix/gas into the cylinders again just to see... no fire. Couple of half-chugs, that's it. Gotta be weak spark. ?

What exactly is tors? Would that inhibit the spark... even at low rpm?

What next?

Getting frustrated...

On a good note... I managed to replace the track on my son's Z440 Cat. First one... the next one will be easier!
 

·
Registered
Joined
·
27 Posts
Discussion Starter #10
Stator? CDI? Would either of these be more likely to result in a weak spark? Both plugs did have spark... seems weird that it wouldn't run at least a little. ??

The stator is responsible for generating the electricity for spark. What does the CDI do? And then, what does the coil do?
 

·
Premium Member
Joined
·
5,737 Posts
the stator produces the juice, the cdi tells it where to go and the coil enhances it for a greater charge. did the new coil come with a new plug wire and boot or did you reuse the old one? stator output can be tested, cdi not.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #12
Well, the "new" coil is one out of a parts sled... supposed to be working. ?? The plug wires look like they are permanently attached.

The coil that's on now has boots on both ends,and look kinda new.

If there IS spark, then is the stator ok?

Do both bolts need to be secure on the coil for it to work? I couldn't get one off, so hooked up the "new" coil with just the one bolt. The bolt with the wire attached is the one I was able to use. It looks like they just fasten to the air box anyway.

Can you test a coil with a meter?
 

·
Premium Member
Joined
·
5,737 Posts
coil can be tested. some of the coils had a ground strap attached to the mounting bolt, must be the wire your referring to. sometimes the wires can get bad on the ends and they will remove from the caps. they are kinda glued/siliconed in. nipping about 1/8" to 1/4" off the wires will create a fresh contact. see if you can see a hitachi or a toyo denso on the coil.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #14
Update:
Got the sled in the garage. Spark is blue on both plugs. Still will not fire, even on gas drizzled in cylinders. Found a questionable orange wire between coil and CDI... redid... no help.

Redid spark plug boot connectors... nothing.

Observations:
Wire harness coming from stator has the 4-plug plus two separate wires... brown goes to handlebar area, and a cream wire is not connected to anything. I don't see any wires in the area, I'm assuming that is has been like that.

There is no handlebar kill switch on this machine.

There is no headlight action when I pull it over... at all.

Lost.
 

·
Registered
Joined
·
27 Posts
Discussion Starter #15
Sooooo, if there is spark, fuel, and compression, but no fire... could it be that the spark is out of time? Is it the CDI that controls that?
 

·
Registered
Joined
·
75 Posts
it might be flooded i thought i was having a weak spark problem and turned out just to be flooded there should be crank drain plugs usually under the exhaust area if fuel comes pouring out this may be your problem
 

·
Registered
Joined
·
315 Posts
tors=throttle over ride sytem
has to do with controling the engine rpms ,
yes it will make your machine have no spark ( did mine) unhook the wires to
the carbs and hook the, not carb, side of the wires together !! and try it ??
if i remember right they are black and black/yellow tracer . the opposite side, wires of the carbs, is the wires you need to hook together , just to be clear !
 

·
Registered
Joined
·
27 Posts
Discussion Starter #19
it might be flooded i thought i was having a weak spark problem and turned out just to be flooded there should be crank drain plugs usually under the exhaust area if fuel comes pouring out this may be your problem
This thing shut down going wot across the lake... I don't think it's a fuel issue... I don't know... :dunno:
 

·
Registered
Joined
·
27 Posts
Discussion Starter #20
tors=throttle over ride sytem
has to do with controling the engine rpms ,
yes it will make your machine have no spark ( did mine) unhook the wires to
the carbs and hook the, not carb, side of the wires together !! and try it ??
if i remember right they are black and black/yellow tracer . the opposite side, wires of the carbs, is the wires you need to hook together , just to be clear !

I will look for those. Although, I DO have spark. :confused:
 
1 - 20 of 33 Posts
Top