Going to be a long weekend!

[PGHMAN]

Like the title states it's going to be a long weekend. I continue to have bog/limp issue with my 98 rfi after 5 minutes of running on the water. Runs like a champ then the dreaded bog. Here's the history:
Rebuilt motor late last summer - new crank, pistons, injectors, OSD rectifier. Did leak test - no issues. Motor has at the best 1.5 hours on it.
Compression 155 each hole
TPS reset
Replaced fuel pump and both filters last week- tested 59 psi
ohmed all sensors all within spec
trimmed coil wires
I am sure I am missing something above but I have been over this ski many times
So, yesterday I had the opportunity to hook-up with one of the owners of the Candoo....a real stand-up guy. Put the ski in the water ran great for 5 min then the bog. We put the ski on the Candoo and it showed no unusual codes. We concluded possible coil pak or MPEM.
Got home grabbed a few beers and hooked to hose ran rough pulled plugs - were fouled. Replaced plugs ran great. Anyone have a coil pak go bad? If the coil is not producing adequate spark then fouling of the plugs - right? It ohms out in spec.
I am at my whits end with this ski but still have hope

 

[ski-d00]

I've seen several new rectifiers last 10 minutes before they start acting up and doing what yours is doing, especially the aftermarket ones. I would try one from a known good running ski, or get a 4tec one, I've had better luck with those in the DIs and RFIs, just change the connectors.

I don't recall every seeing a weak coil, they seem to work or not work, but are very reliable and very rarely fail.

 

[PGHMAN]

The rectifier is a 4tec unit. I also performed dynamic test 13.7 at mid/high rpm. Pulled rectifier when it's gone into limp mode - no change.

 

[ski-d00]

have you tried another rectifier from a known working ski. the voltage output doesn't really mean it's working properly and pulling it doesn't seem to work very well like it does on the carb skis.

when it bogs, is it firing on both plugs? if you shut it off after it bogs, and restart right away does it go another 5 minutes before bogging? as soon as you change plugs, it always fixes it? or is it just the time to change the plugs fixes it?

 

[PGHMAN]

I have tried another rectifier from a friends ski - same thing....bog. Not sure how to tell if it's firing on both plugs when it bogs? Can you explain? After it bogs then restarts with the bog. I didn't replace the plugs yesterday while at the lake to verify if it would resolve. Did so when I got home, connected to hose started and was running poorly. Put new plugs in ran well.

 

[PGHMAN]

Also, have ran with seat off to eliminate any exhaust issues that I have read about. Pulled rectifier during bog as well.

 

[ski-d00]

an inline ignition tester, http://www.harborfreight.com/90-inline-ignition-spark-checker-69023.html or an inductive timing light works well also because you can tape the trigger pulled and keep it up in your lap while on the water. http://www.harborfreight.com/xenon-timing-light-3343.html

 

[PGHMAN]

Thanks Ski-Doo for the tips! Had not thought about that.