I bought a 96 challenger that hadn't run for a year. The rotary valve was seized but the engine looked good so I had it broken down, cleaned, and put back together. The boat ran fine for an hour then the o ring on the cylinder head split dumping water into the rear chamber. A new o ring fixed it for another hour untill that one went, and there was water in the chamber again. I replaced it and it ran fine for 1 minute until at full throttle i was only getting 3000 rpms. Pulled the plug, no water. Cleaned and replaced it, 1 minute of running perfect then the same thing happened. The boat was loosing the rear cylinder after a minute of running fine, no matter how many plugs I changed. Aftrer three days of sitting, it started right up so I took it to the water. For the past three days, I can run for about 15 minutes before the engine dies out and gives me about 4000 at full throttle. It runs mint for the 15 minutes though. I cleaned the fuel filter, the carbs were cleaned a week ago, there is spark in both cylinders, no more water is getting in through the head, and I have 180 psi in both cylinders with an r&d head. I need serious help or this thing is going to drive me crazy. I have tried bypassing the rectifier, clearing the gas vent line, running with the cover off, testing the electrical with an in line spark tester, sea foam in the intake, and the engine is cool to the touch, all with no help. The spark is consistant while the boat is running fine, and when it is struggling. I don't know where to go next.
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96 Challenger dies after 30 minutes
- Thread starter BCSwider
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timmyboy76
New Member
hey...with 180psi, you running higher than 91/92 octane. Might be hav'n detonating problems...also, you double check the Rotary Valve timing?
The o ring on teh head of the seadoo won't with stand 180 psi...That compression is too high for stock oring. Most are set to run at 150 psi maxed. Either get a up graded oring or replace the head with a stock unit to get the compression to 150 psi.
Karl
Karl
still nothing
I knew the head was a problem, so I ordered a new one. That doesn't solve the problem I'm having though. I can run good for thirty minutes before bogging down to 4000 rpm. Could this be a carb issue even though the had been cleaned and looked good an hour before this happened? What about the computer, would it do this? Took apart the rave today, looked real good. I don't get it and I'm about to walk away from this boat $3000 in the hole.
I knew the head was a problem, so I ordered a new one. That doesn't solve the problem I'm having though. I can run good for thirty minutes before bogging down to 4000 rpm. Could this be a carb issue even though the had been cleaned and looked good an hour before this happened? What about the computer, would it do this? Took apart the rave today, looked real good. I don't get it and I'm about to walk away from this boat $3000 in the hole.
robin savell lloyd
Active Member
When ever your engine dies is when you need to trouble shoot it. hopefully it dies and will not restart that would be easy to figure out I think. You would need to see if it has spark and fuel. If you are able to start it up each time that may be a different story but hopefully we would be able to help you on that isue allso. :cheers:
It never stops running. I will be at 40mph and the thing will just bog down to about 4000rpm. I need to keep the throttle on full to go about 10mph. If i drop it all the way back to idle, then to full throttle, i get about 5 second of acceleration, then back to 10mph. I don't think it is rev limiting due to the fact that the spark tester flashes when the boat is limiting revs, it is solid when i am having my problem. The guy who put it back together is pretty sure that its not the carbs. He's thinking computer, something in the foward controls, or rectifier. Could the water regulator do this?
robin savell lloyd
Active Member
Have you cleaned your rave valves if you have them? and if that does not do the trick I would have to say that it is fuel related. :cheers:
robin savell lloyd
Active Member
I am leaning towards a fuel problem. :cheers:
robin savell lloyd
Active Member
yes :cheers:
robin savell lloyd
Active Member
It sounds like carbs are clean but you have some sort of fuel delivery problem. I would check from tank all the way to carbs. Could be the fuel pump diaphragms but I would lean towards a fuel restrition in the tank, valve, vent, or lines. :cheers:
robin savell lloyd
Active Member
well if if you can run it with the fuel cap off and it runs good then the vent is blocked. If that does not help then make sure that you have a constant supply of fuel from tank check for about 30 secounds. if that is good make sure that you can blow threw all the fuel lines, all the way to the carbs. if that is good than you may have bad fuel pump diaphragms or for some reason your pulse line coming from engine is cloged or has a leak and will not alow the fuel pump diaphragm to pump fuel properly. This is only guessing so good luck Robin :cheers:
robin savell lloyd
Active Member
I would not think computer as you say that you can bring thottle back to idel and then you will have power again. I would be willing to bet money that would be a fuel delivery problem in stead of a computer problem. :cheers:
robin savell lloyd
Active Member
I would think that you should be able to check and see if you are geting enough fuel when this problem happens by removing the the fuel return line with the engine runing after it falls on it face back down to 10 mph. Fuel should becoming out of the return line. That will show you that it is pumping more fuel than needed. If it is not pumping more fuel than needed it will starve the engine and not alow the rpms to rise. Make sure you are carefull when doing this have somthing to catch the fuel have fire exstingusher ready. Insurance for your boat is less than $200.00 for a hole year. This may not be your problem this only a way to trouble shoot the problem. :cheers:
rexsteiner
Active Member
if the fuel checks out i would look towards the timing. did you double check the rotary valve like timmyboy76 suggested?
robin savell lloyd
Active Member
I would not think timing as it runs good for 15 minutes. could be a problem with the pulse going to the rave vavles. These are only guesses so good luck. :cheers:
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