97xp, still problems HELP!!!

[pasha]

Here is the story:
1997 XP.
Some of you may read my previous post where the engine was glow plugging, ran too high and no carburetor adjustments helped. I discovered that the plug that covered the balance shaft was missing due to broken snap ring. When I stripped the engine for that repair I also noticed that one piston has seized. I rebuilt the motor and the carburetors. Reinstalled everything back in the hull, aligned the engine and before I did that I even flushed the gas tank, replaced all fuel lines and the fuel filter. When I started it up, the engine still ran rough on idle and still had some backfiring issues. However it no longer would run away and would always start up and stop with a push of a button. I assumed couple of different reasons for it to run crappy, such as the carburetors. With no further delay I took off the set of carbs of my other 97XP (which runs perfectly) and dropped them on this ski. It started to run a bit better (a little better adjusted carbs) but still ran not as good as the other one. I did a quick clean of the original carbs and put them on my other 97XP (that ran great) and it continued to run great too. So carbs were not the issue. I bought a timing light and performed the timing test which I “think” revealed that the timing is retarded by around 2 or 3 degrees. I believe that my theory is correct and this timing was off originally which caused previous set of problems. Retarded ignition caused un-burned fuel to be sent to the exhaust pipe, where it would burn up eventually. Thus blowing the rubber hose, the one that is between the exhaust pipe and the pipe that goes to the water box. Overheating and etc.. What do you think? Could this could this?

[stevepaulus]

I was told there is a tolerance of 5 degrees, but i would imagine if the timing is not perfect your performance will not be perfect.....just my opinion.

[pasha]

well kind of weard for me...
carbs came of perfectly working ski...
compressin is 145mag/150pto. correct spark plugs, correct gap.
and on other hand. MPEM programmer allows you to change ignition only 3degree 1 way and 4 other. so I guess it metter.
anyone from SBT can help me?

[ October 10, 2003, 09:51 AM: Message edited by: pasha ]

[stevepaulus]

Dude...if the carbs are right and no problems in the fuel system, it's your timing? Did you put the magneto cup in the right place, if the timiing is retarted on the RV of course you will not see peak performance. And when you say FLUSHED, WHAT DO YOU MEAN? Did you mop the tank out? Or did you force air through the whole fuel system?

[pasha]

Dude,

I have removed tank out flush it with water, let dry for 2 days, while this **** is stinks as hell and my wife was ready to kick me out from the house.... than put old sock on the stick and wipe out everything inside...
replaced every single fuel hose.... including vents. Replaced fuel filter, rebuld carbs...
I don't know what else can I do... lap dance on the hood??? ? [img]/graemlins/winkanim.gif[/img]

[ October 10, 2003, 10:15 PM: Message edited by: pasha ]

[stevepaulus]

Then the only thing that i can suggest is to pull the carbs off and check them over again.

Did you flush the fuel system before or after you rebuilt the carbs, maybe some debris somehow got back in them.

Other than that i don't know what else to tell you, maybe someone else can help.

[Bill O'Neal]

5 degree tolerance? No way! not on the ignition timing, only on the RV timing. Information like that is dangerious!

When you say "runs crappy", exactly what does it do wrong?

Not accellerate? Not reach max rpms? Backfire? Stalls at speed?

[pasha]

Bill,

Thanks for your replay...
anyway here is my problems...

It looks like RV been in wrong position ~10deegree.... during this time it was backfiring and running like **** ...
now RV position has been corrected and it is not longer backfiring, however now it runs away and I can't get stable idle speed.
I have pulled sparc plugs and it looks to me that PTO cylender it running lean and Magneto is rich....
Both carbs set the same and been moved from working boat with good motor.

-p

[dank]

Then the pto cylinder may have an air leak from the rear crank seal, base gasket, head gasket, intake? If the carbs are right and the rear cylinder is running lean enough to run away then it is a big leak. Block the intake and exhaust and pressure check the engine.

[Bill O'Neal]

I agree. Sounds like you have an air leak.

[stevepaulus]

Bill and anyone who is wondering,

I was referring to the RV timing, guess i was not clear enough..sorry

[stevepaulus]

I just re-read the originall post..my bad, i didn't catch the part about the ignition timing.

But, how can you screw up the ignition timing on a 97 XP.you line one of the triggers with the hole on the flywheel, so how can it be retarded only a couple degrees? It's either right on or not even close. What am i missing here?

Sorry for the dumb question, been a rough week.

[pasha]

steve,

if crank been replaced it could be different by 1-2 degree.

-p

[stevepaulus]

Pasha, i know the RV timing can very 5 degrees, but on the magneto(ignition timing) it either lines up or it don't. There are to triggers on the magneto cup, line the edge with the hole on the flywheel. So, the ignition timing is either correct, or not at all

[Bill O'Neal]

Steve,
You are wrong about that. Although it would seem to be impossible to get the timing off, it isn't. Changing cranks or flywheels can make a difference in timing, and you are totally eliminating the advance or retard that can be attributted to electronic drag in the MPEM and pickup. If the timing were always perfect by just bolting the mechanical parts together correctly, we wouldn't need the programmers and the timing lights, and the correction factors that we use to get them right on the money as far as initial timing goes. Sea Doo would not have the need to stamp a correction factor number onto the cases.

A retarded motor will perform poorly and never meet the expectations of the owner. An overly advanced motor will detonate the pistons out of it eventually.