1993 GTX - Cranks but no start - Help!

[Mark 67]

A friend borrowed my 1993 GTX 580 (bought recently) but failed to replace drain plug, as a result hull filled with water and engine quit. Upon investigation the plug wires were cracked/frayed and suspect that water contacted plug wires (where cracked) and disabled the electrical system. While water injestion was possible/suspected we are not 100% convinced that this actually occured (inside of airbox was dry upon inspection).

On shore the machine cranked but would not start.
Our diagnosis revealed that there was no spark at end of plug wires but there was spark coming into the coil. Therefore we replaced the coil/plug wire set - engine still cranks but will not start. Battery was replaced with new one as cranking eventually drained the old battery and spark plugs are new. A mechanic (primarily snowmobile) checked the stator for spark (checks out ok) and confirmed that all grounds are ok. All fuses checked out ok.

Any one have an idea as to what could be causing this 'no spark' condition? Could it be the module (MPEM) and how can we confirm this (not cheap to replace so don't want to replace it if not needed). I noticed in other messages that if one were to disconnect and re-connect wire on flywheel cover (?) this might affect the no-spark condition - is this worth a try?

Will really appreciate anyone thoughts or suggestions on what we should do to diagnoze and solve this problem.

[Bryan Glynn]

Remove the plugs from the head, put them in the boots, lay them on the head and crank it over - do they spark?

Did you remove the plugs and crank it over to see if you had water ingestion, or just look in the airbox?

[Mark 67]

Brian, there is still no spark at the end of the spark plugs.

We did pull the plugs and look in the cylinders - we turned the machine on its side and cranked the engine with the plugs out and there was a small amount of fluid (smelled like fuel) that was pumped out of the cylinders, but cannot definitively rule out the presence of water (know how destructive this could be re: crank bearings, etc.). As engine would not run we could not flush engine as we always do after use.

[Bryan Glynn]

If the coils are new, the plugs are good, the wires are good and the stator checked out, then the CDI is probably the culprit.

If you didn't have a small geiser of water, but just a small mist (probably fuel, you're right) then I wouldn't suspect water ingestion.

[Mark 67]

Thanks Brian. Forgive my ignorance but is the CDI the same as the module (MPEM) or are these actually different? Is there any way (i.e. tests) to definitively isolate the CDI as the cause?

[Bryan Glynn]

On that particular model, yes they are the same unit. www.epowersports.com has the low price: Part# 278000070 $217.78

I would first go through and check each wire for a good connection, but no, there is no way to effectively test the unit.

[Mark 7]

Hi Bryan,

Finally got hold of a CDI unit part#278000070 - but I have one more question. The CDI unti on the doo now is #278000262, dated 92/12/11. Before I install the replacement CDI (non-returnable once box is opened) I want to try to be sure that the replacement CDI is the correct one and I'm concerned that it isn't right given the different part numbers.

Can you shed any light on this? Is it ok to install the new CDI and will it work even though the part numbers are different?

Thanks again in advance.

[Bryan Glynn]

That's fine - 070 supplemented the old number.

[Mark 7]

Thanks Bryan.

Two last (hopefully) questions. Would you know whether the new CDI unit comes with the 5 or 6 wires (including connecters) to connect to the rest of the electrical box?

Do I need to put any coating on the connectors when installing the new CDI (the existing wire connections look to be which looked to be covered with clear plastic sheathing) when I connect the wires to the other wires in the electrical box?

Thanks

[Bryan Glynn]

6, and the plastic doesn't seem to help with protection much - they still corrode and need to be periodically cleaned anyway.