Super Jet Calling all mechanics......i need serious help!!!!!!

[EXPERIMENTAL]

So, I will skip the build story of my boat, that is under "my ski" thread under "$2300 superjet gold" search it if you want the whole story start to finish.
http://www.x-h2o.com/threads/73366-2300-Superjet-Gold&highlight=
this will tell you everything i have on my superjet

Here is my problem..... My boat runs awesome with a new set of plugs (gap is correct, plugs type is correct). After running for a period of time (it varies) my boat will start bogging really bad, like it is loading up with too much fuel, to the point that it is like a plugs get fouled and i am running on only one cylinder.......well that was at the end of last season. We took it out of the water with plans of a complete overhaul


winter comes, we have stripped the boat......

1) we thought it could have been my msd enhancer.....we put my dad's old stock electronics back in mine.......did the same thing

2) replaced spark plug wires and spark plug boots

3) thought it could have been my carbs........sold my old riva pro series 48's and got a new set of black jack 46's from art at jetworks........still did same thing

4) thought it could be my exciter coil (could not be my charge coil because the battery continues to be recharged).....replaced the exciter coil, and because we found some blow by in the front of the crank case, we cracked the bottom of my cases open and replaced the two rear and one front crank seals


one thing that my father and I cannot explain is.....when i come in from a ride (whether or not it went good or bad) I will have this white foamy substance in the inner lips of my carbs. This is under the flame arresters (i use prok flame arresters with blowsion outerwears) what could this be? It has happened with both my riva pro series AND now my black jacks

seriously i have not had a reliable ride in TWO years!!!!!!! (meaning i cannot go farther than 300 feet from the dock because i am afraid of be stranded)

I need some serious help with this or im going to go crazy!!! im about at my wits end with this things (no i will not sell it), i just want to have fun again and the freeride is coming up at Lake ozarks (last year the only remedy i could find was to replace the plugs, i went through 10 pairs of plugs in one day alone)


PLEASE HELP!!!!!!!!!!!!!!!!!!!!!:1zhelp:

 

[TOBY]

take the waterbox out and see if it has a brokin baffle that is flopping around.

 

[EXPERIMENTAL]

how would a broken baffle effect it like that.....??

 

[Matt_E]

The charge coil does not charge the battery, the lighting coil does. The charge coil powers the ignition.
Check your reeds.
You might also have water leaking into the motor.

 

[EXPERIMENTAL]

when we replaced the carbs, the reeds were great, solid pressure and good seals......water could have something to do with it, because of the white film on the carbs? its almost like a watery whip cream substance........so if we replaced the exciter coil it could still be another electrical part failing?

 

[Matt_E]

Yamaha calls the stator coils pulser coil, charging coil, and lighting coil. What color wires came off the coil that you replaced?

 

[waterfreak]

The charge coil does not charge the battery, the lighting coil does. The charge coil powers the ignition.
Check your reeds.
You might also have water leaking into the motor.

I think Matt is right about this one! check your compression. A partially blown head gasket will cause this.
is your cylinder ported? if so maybe somebody went through from the transfer area to the water jacket...I've seen this before !

 

[EXPERIMENTAL]

not sure which coil we replaced (im sure my dad can chime in on this one), but last winter (when the problem first showed up), i believe we replaced the entire gasket system from my protec head.......also replaced the intake maniforld gasket, carb gaskets, and both b-pipe gaskets......

 

[Matt_E]

Did one piston look a lot cleaner than the other?

 

[SXR-FOREVER]

I've had a head pipe gasket do this to me too.

Also the foamy stuff in the carbs is from water and fuel mixing...I chased this on my old ski forever until I realized that one of the bilge hoses had a crack in it and when I turned the bilges on a stream of water spray directly into the flame arrestors. Probably a 1 in a million happening but its something to check.

 

[cookn]

I also agree with water getting in. I had this problem with my copper head gasket. the gasket was new but the head i put on did not have a true enough mating surface. the ski would run great as soon as i put it in the water and the power would die off just as your describing. The plugs would have water drops on them where as if they were fouled they would be black and oily.

 

[Breese08SJ]

It only takes a little bit of moisture to make that white foamy mess you speak of appear on the tops of the carbs. I wouldn't say that is your problem look else where for a water leak, If you have the time I would also pull the stator cover and check that the stator is plate is tight, we had the bolts come loose on a friends ski and we chased intermittent problems for over 4 months. Def check the compression even if it is perfect at least you have a base line for the future if other problems arrise.

 

[EXPERIMENTAL]

haven't checked compression lately (but will do so soon), but when this problem was happening last year we did check compression and it was normal. i believe stator is tight, because we took it off to put on new coil, then torqued it to factory specs.

both pistons look like the same (a little black from oil, not washed, but also not dripping with oil), but the plugs are a different story, one looks like a nice cocoa brown, while the other (im assuming the problem cylinder) is very black, with standing fresh unburned oil on it.

is it possible that each of my cylinders needs its own specific tuning? right now we have both cylinders (high and low carb screws) tuned the same.......

 

[Matt_E]

A standup does not need to have each cylinder tuned separately.
Are your carbs both the same or did you piece them together?

 

[EXPERIMENTAL]

they are brand new black jacks from art at jetworks.......told him what i had on my boat, he jetted them and did the linkage with my manifold and i put them on

 

[Matt_E]

I'd look at water intrusion if it runs fine for the first couple hundred yards and then bogs down.

 

[waterfreak]

the white residue you see at the top of your carbs is just somewhat a mixture of water and fuel from the carbs. It is normal if you have a tendency to ride hard and have water in the hull. You may want to invest in OEM carb flame arrestors .

I still think you should pull your head and inspect the gasket or o-ring (if aftermarket) also see if wash area in the domes are different. This could tell the story as well.
then, take a pic and posted

 

[EXPERIMENTAL]

i will look into possible water intrusion, father said we replaced the lighting coil (also known as the exciter coil)............

in all honesty, this thing has me so stumped, its not like it bogs a certain point in time during the riding it just seems like it will be running fine, them you are burping the throttle to jump some waves or even just riding around (with bilge pump on always, so not really much water sloshing around inside) and then it will just start getting worse, and the its like a light switch, it just bogs completely and im limping it back to the dock

 

[Matt_E]

Is this in saltwater?

 

[EXPERIMENTAL]

fresh water only! never rode in surf, even though it sounds amazing