No spark on total loss

[Waternut]

Ok so this morning the engine was getting spark just fine and before that was getting good spark all summer as far as we can tell. We've been struggling with carb tuning issues though.

However, this morning the spark got to be virtually non existent. It will typically spark once when you hit the starter button and that's it...sometimes not even once. If I pull the total loss wires apart and touch them together it will spark great over and over. If I loosen the flywheel and spin it by hand it will spark great over and over. However, when it's all buttoned up and the starter is going, the spark is very random and usually only the first time it turns over.

We've even tried a different and pablo says he ran an extra ground from the head to the starter ground strap. The total loss is connected straight to the battery on both positive and negative.

The only things I can still think of that could be wrong are the coil and the starter. Maybe the starter is drawing too much current and the battery can't support a spark too...or the coil is toast.

 

[Pablo]

Ok so this morning the engine was getting spark just fine and before that was getting good spark all summer as far as we can tell. We've been struggling with carb tuning issues though.

However, this morning the spark got to be virtually non existent. It will typically spark once when you hit the starter button and that's it...sometimes not even once. If I pull the total loss wires apart and touch them together it will spark great over and over. If I loosen the flywheel and spin it by hand it will spark great over and over. However, when it's all buttoned up and the starter is going, the spark is very random and usually only the first time it turns over.

We've even tried a different and pablo says he ran an extra ground from the head to the starter ground strap. The total loss is connected straight to the battery on both positive and negative.

The only things I can still think of that could be wrong are the coil and the starter. Maybe the starter is drawing too much current and the battery can't support a spark too...or the coil is toast.

We tried 3 different coils (all used) and each gave us virtually the same response. An initial spark and then with each subsequent revolution there was no spark at all. Waternut hit the nail on the head with turning the engine over by hand, via the flywheel, we were able to generate a constant spark with each revolution. We pulled the flywheel to check the airgap and got a measurement of .60 with a micrometer. I had lots of grease on the pickup and flywheel from doing a sloppy job greasing the bendix. Does anyone know if grease buildup will inhibit any of the electromagnetic signal from flywheel to pickup? After gettng that good response when turning engine over by hand I assumed all was well. We torqued flywheel back on put it all together and had nothing. We went from a regular spark to poor spark to no spark and consitantly nothing with 3 different coils. Any suggestions???

 

[norcal ex]

that is usually the sign of a bad ground....

 

[SUPERTUNE]

Make sure you draw a line across the ring gear and the flywheel and make sure you don't have a ring gear slipping when cranking it over.

 

[Waternut]

Make sure you draw a line across the ring gear and the flywheel and make sure you don't have a ring gear slipping when cranking it over.

Never would've thought of that as a possibility but I know the pistons are moving up and down because I can feel them pushing air up as I ground the spark plugs on the head looking for a spark.

 

[bllewis394]

i know im a nub here but i had a similar prob with a stock square once. the fuse was my problem. it was pretty corroded inside the glass and would lose it's conductivity when heated. i no longer run a fuse and i don't know if you do either but it's something to check out i suppose.

 

[Waternut]

Well I'll dig into the main battery cables tomorrow and see if that's the problem after I fix my ski. I remember reading that when a starter is on it's last legs, it will draw so much current that the coil doesn't have enough juice to produce a spark. Is that true? I doubt I'd be able to measure the voltage going into the coil with a digital voltmeter.

We have two batteries but I'm a little scared to try for fearing of frying the brain...anyway, what if we hooked the total loss components to one battery and the starter to the other battery? Would that work?