What is it?
hi i am currently looking at this 2000 jet boat to buy and one engine runs ok the other one does not fire up i am an ex tech for gm but never worked on 2 and 4 stroke ther than put plugs and gas in them so heres what i observed when i looked at the boat : i took compression in both cylinders its up above 200's in both cylinders i put a plug in each wire boot and grounded the threads with a jumper cable and i have spark on both of them i did not really smell any fuel comming out the cylinder plug holes but it was sitting for a while and he had fogged the motor for winter the guy says it will fire up but will rev high and then die and not restart the motor sounds like it cranks ok and i am going to get the boat for pretty cheap anyone know if i am running into anything thats :common" for these things or anything that could be the problem ,....i did not check some more things that i wanted to as i want to buy the bot cheap and do not really want to "find" the problem for the guy but i don't think it gets fuel or enough of it also the gap on the plugs was really small i thought and spark looked kinda weak as opposed to the kind of spark i am used to seeing in auto engines so wonderring idf all this is the norm or no any help would be appreiated and thanks in advance take care
doug
I see you found out how to get started, except you put it in the jet ski section. I will move it to the boats for you.
It sounds like you might have some problems with that engine. From your description, it sounds like it's a Speedster. They have twin engines. You'll find the twin engine configuration with the 717cc or 787cc set up.
The compression in the other motor, what was it? Compression in these motors should not be over 150 psi stock. If your getting 200, then there is too much oil in the cylinders. I'd be looking into the rotary chamber seals. IF these are leaking and bad, the crankshaft has to be replaced. If the boat was just sitting up, then this is likely why there is so much oil in it. You'll need to blow all that oil out and try to do a compression test again. Or, if you can start it, do that then a compression test afterwards. You can pour a capfull of premix (or with so much oil in the engine, regular gas) and put your plugs in. Put your lanyard on and try to get it to hit. If it starts, run it for a few seconds and shut it down. You do not have to worry about connecting a water hose to it at this point. After you shut it down, then try the compression test again.
Beeps? When you put the lanyard on, make sure you get two audible beeps. IF you grounded a plug and got spark, then I'm sure your MPEM (multipurpose electronic module) is ok.
Runaway engine? If he's saying that when he starts it, it runs away, this is usually caused by a leak somewhere and is sucking air. This will also cause a lean running condition. If it goes unchecked, it can cause the engine to start a diesel effect that cannot be shut down by killing power. You have to choke it to stop it.
Find out what kind of oil he has been using. IF he's using a TCW-3 oil, then he may have damaged the engine. Rotax requires a low ash, non NMMA, non TCW-3 oil.
That should get you started. You got to get a good compression test. Record all 4 cylinders and repost them here. What you got on one motor, then what you get on the other.......
Don't get excited and then buy something that you will be sinking money into.:cheers:
