I am having trouble getting my jet ski up to speed on start up. It runs about 15mph and stumbles for a couple of minutes and then gets to 35mph. It use to go 47 mph. Any ideas.
I am having trouble replying, so here it goes again. I am not sure of the engine performance
or revs. The problem seems to be a carb problem in that it stumbles when I open the throttle
where it wants to die like it is getting too much air and not enough gas. What I can't under
stand is why this problem goes away after about two minutes. Don't this propeller slippage.
Any thoughts? Oh, I did rebuild the carb late last year. Dave
Best way is to get a kit, strip it all the way down and clean everything with carb cleaner, blow dry with compressed air and make sure all the little orifaces are clear, reassemble using the old needle and spring.
Thanks for your info which I assume means a carb rebuild. I will do that. However, while I wait for a kit, I am concern about your info on the possibility of the impeller slipping. It there a way to rule that in or out? Thanks
If it was cavitation you would know it. Would feel like a slipping clutch. Only way to check it is with a feeler gauge to check impeller to wear ring clearance. If your not going to pull the pump, you might be able to pull the intake grate and reach in that way.
OK being perplexed is an understatement. I still have the problem of the jet ski only getting to 18-20 MPH. The normal speed is in the 40s MPH. On odd thing is that the speed gets up to 35 MPH occasionally. OK I have rebuilt the carb again. I was meticulous in the rebuild, did everything but recheck the pop off pressure which was OK the last time. I was very careful in the reassembly. I did not replace the needles and springs.
I checked the engine cylinder pressure, the pressure for each was 90 PSI. The spec for the engine output is kW (PS)/rpm = 66.2 (90)/6350. I believe the engine is OK. The jet ski body is great shape. The impeller is secure. Maybe I need another carb. Please let me know what you think. Thanks, Dave
Thanks for replying. Would it be reasonable to expect that both cylinders would degrade from 145 PSI each to 90 PSI equally? I am ready to place an order for a SBT engine based on your information unless you think I somehow measured the 90 PSI each incorrectly. Thanks for your help. Dave
What are you using for a compression guage? My suggestion would be to rent another tester from local automotive parts store and retest to confirm numbers.
Yes, some times they wear even or very close to even.
Don't order from sbt quality is substandard. Pwcengines a much better option.
Superior in the fact I've seen missing crank/rod spacers in there cranks. Missing wrist pin/piston spacers. Incorrect main brgs installed. The list goes on and on. This is what I've seen. Search the pwc sites you'll find others with same sightings. I just don't trust them. There quality just isn't there. It's about a 50/50 Gamble and I don't like those odds. They fall back on there warranty. Witch then costs the costomer or mechanic the replacement cost.
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