96 XP 787 Rev Limit Problem

[BlackWS.6]

Starts and idles easily but when you try to get on the trottle wide open the engine bogs down and loses fire as if the rev limiter is coming on around 4 grand. From what i have read in my repair manual all the symptoms points to they CDI, ie..like fouling sp and intermittant spark, etc. Have already verified the fuel system is clean, carbs are synced, oil pump and throttle fully adjusted. Is this a issue possibly with the CDI ignition system since the rev limiter is built in the CDI.? Just need to verify that is the CDI before i do anything else. Also from reading around the 5 amp fuse was blown also, and i havent tried replacing it yet to see if it corrects the problem. Basically I need Any advice on what to do? Thanks guys

 

[K-9Soldier]

Hey Black... well just got done dealing with the same problem with my cousins 96XP... I know you said the fuel lines are cleaned but have you replaced them with new fuel line? The stock fuel line deteriorates after the years into a sludge that eventually can create a blockage in the Fuel Valve(selector). We replaced all the fuel lines in our ski which were clear when we checked but had a major blockage in the fuel valve. The ski would start up and you could rev it out of water and it sounded great, but once you had the ski in the water and put the motor under a load, the ski would bog off acceleration and cut out after mid-throttle... After cleaning the fuel valve the ski ran great! The reason the ski may run with a clogged valve is because there is not much of a load on the motor and fuel pump so the motor can still run on a minimum amount of fuel, but once there's a load on the motor the tiny fuel pump may have a hard time sucking fuel past a partial clog... So you might want to pull off your fuel valve and check it if you haven't. When the valve is on the gas or reserve position, you should be able to blow right through the valve no problem... you may also want to check the Pulse line which connects the fuel pump on the Mag(front) carb to the engine and creates the vacuum needed to work the fuel pump. Make sure the line isn't cracked and all the clamps are tight other wise the pump may not work if there is a lose of suction... hope this helps

 

[BlackWS.6]

K9...Yea it has new fuel lines all the away around the ski. The fuel valve selector i pulled off the other day and cleaned it out and blew it out with compressed air and carb cleaner. The carbs have also been rebuilt and i even had them cleaned again a couple weeks ago..I have also cleaned the fuel filter and the fuel filter in the baffle of the pick up in the gas tank. Yesterday me and my buddy even by passed the fuel valve selector and it still wanted to bogg at higher rpms. So whether it is on, res, or not even hooked up to the fuel valve it still wants to bogg as soon as you open it up and that is in the water or just hooked up to water in my drive way. But it will sit there and idle forever just cant move it anywhere. The main reason why i ask is that a friend who helped me work on them is a pretty good small engine mechanic and has worked on some yamaha wave runners before and rebuilt two of those. Yet he has never worked on sea doos before i have a shop manual and he is pretty smart so he has been helping me work on them and cleaning and replacing fuel lines. But yet we still have the same problem with the reving so he seems pretty sure after reading through that shop manual that the cdi box is out. i just wanted to see if somebody else on here could maybe confirm or point me in another direction to try before i have to buy a F'in expensive part..