FX-1 I seem to have buggered it all up...

My ski has been running fantastic since I put it together and started riding this spring, but I ran into some troubles a few weeks ago and I cannot figure it out. It started with what seemed like the plugs fouling about once a day, then it started losing power, then turned into a complete basket case. I pulled the motor and found the ground cable going to the starter had broken (the ONE cable I had reused from another ski). I fixed it thinking that was for sure the problem, but it still ran like crap. Rough idle, felt about like a stock 701 power-wise, just didn't sound right. It also ran away a few times on the trailer so I did a leak down test and found the rear fuel pump was missing a rubber seal between the clear plastic diaphragm and outer plate. Crank seal didn't leak at all. Back in the water today and it still feels weak as hell with a rough idle, but no longer runs away. So far I've had the carbs completely apart with no issues other than that missing seal (pop is 29-30 with new needle/seats), compression is a bit low 155 rear/160 front but it might be my old gauge. Reeds are good, cylinders and pistons look great. My carb settings are exactly the same as they were this spring. Is it possible the broken ground damaged my CDI or something? Spark appears to be fine...


Setup:

Xscream 840cc 6mm 62T/61X
44mm BJ carbs set up per Arts instructions (his jetting seemed dead on)
ATP Epic
Bpipe
 

swapmeet

Brotastic
Location
Arlington TX
With your mention about the ground, I might suspect the CDI. Or maybe you have a poor ground connection in general, causing the rough running.

The running away thing doesn't add up tho. Perhaps you have two separate issues. That could be a in a few places, intake, carb bodies, etc.
 

JetManiac

Stoked
Site Supporter
Vendor Account
Location
orlando
Have you checked the quality of your spark? Tried cutting back spark plug wires and installing new boots and terminals yet?
 
No, I have not cut the wires back yet. However, I did use a brand new JSS coil at the start of the season and I ride freshwater. I am always careful to clean and apply dielectric grease to all connections when I am putting electrical components together. The broken ground cable looked great on both ends; the broken section was hidden by the factory shrinkwrap. I'm thinking about trying to put my buddies 48mm full specs on to see if the carbs are the problem or not. They are jetted for a PHP 898 with a PFP, but I think they might be close enough to work.
 
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