Super Jet 701 not holding compression and I need a spark plug interpretation!

[Skirunner24]

I just picked this ski up a couple weeks ago and this morning was the first time I've had the chance to actually take her out. As you can see it has a b pipe and an ADA head as far as bolt on's go. As soon as I hit the water I knew it was running on one cylinder. The front cylinder is much cooler than the rear. Checked spark and it was strong. Rear cylinder holds at 155 while the front cylinder reaches 155 and drops about 5lbs every 2 seconds. I pulled the head and didn't see anything obvious (maybe someone else will). This is my first SJ after working with kawi's for the past 5 years. So, I'm still trying to get familiar with the motor.

I ran new plugs for this morning's ride and when I checked the front plug it looked like this:

I'm definitely no expert on reading plugs and was hoping someone could help me out here. About a quarter of the plug is dark black. Is this indicative of something in particular?


Obviously I'm losing compression. Is it likely needing a new set of O-rings or something more? Any help would really be appreciated. Thanks guys!

 

[WFO Speedracer]

I would try a new set of Head o-rings first,not many other places it could be leaking compression, how did the water stream coming out of the pisser look?

 

[Skirunner24]

Pisser stream looked strong.I didn't notice any sputtering or air passing through (although I wasn't looking for anything at that point) Is there a good place in particular to get the new orings from? Or just straight from ADA? Edit..Just ordered from mcmaster parts.

Anybody else able to shed some light on the plug coloring?

 

[Skirunner24]

Another thing...this may be a really stupid question, but I looked/searched all over and couldnt find anything. Is there a trick to removing the domes from my ADA head? They seem to be stuck in there pretty good and I don't want to risk marring anything up trying to get them out. Any tricks???

 

[Dmac80sc]

Dumb question but do you have the plugs out of the head? If not then the domes wont come out. On both of my ada heads then just come right out easliy. They might just need a little pry if they have been tighten down alot. Or some jackass used 5200 to hold in the orings.

 

[Skirunner24]

I got them out last night. Ended up using some pb blaster and a socket to knock them through. They were corroded in there pretty good. Anyone else with a reason on the bizarre plug coloring??

 

[Skirunner24]

Took the ski out this am after getting everything back together with the new orings and I'm still having the same problem (I also shimmed the domes). She was holding strong in both cylinders at 185 psi. Ski just bogs and is basically running on only the rear jug. I'm going to tear into the carbs in a bit. If anyone has any other ideas/tests etc.... please throw them at me.

 

[tor*p*do]

front carb may be plugged, internal filter clogged
or needs a new diaphragm
piston wash on the front looks a little lean also

 

[fatboyktm]

Cut you plug wires back and instal new ends on them.

 

[Skirunner24]

Ski has brand new coils with MSD ends. I'm pretty confident I found the problem yesterday. I disassembled the carbs and found some interesting stuff. One carb had a fair amount of sand and debris in it. The fuel pump gasket was also out of its trough and assembled completely pinched. This caused the black flat gasket to rip. I also found the needle/seats to be extremely worn (indentations of around .5mm on one needle). Additionally, the high/low speed screws were also very worn/bent and looked to have been bottomed out a couple times. I've got full rebuild kits on the way. Should clear up the issues. I've got pics of the components I'll upload later.

 

[Honda118]

Post update bro

 

[550headache]

fix the problem?

 

[Skirunner24]

Not exactly. After rebuilding carbs I lost spark. Now chasing that problem.