Revving Consistency Problems. and very mad wife !!!!!!

[customglassgy]

Hi my name is frank and my wife and I purchased a 14 ft 2000 Seadoo Challenger with 2Rotax engines. This is my second seadoo. The other is a regular one and not a boat. My prob is this
The boat idles very nicely. And also screams at full RPMS. But besides that I have issue that one motor is way behind on revs and does not match the other and thus jumping out of the hole is no fun ( no power ) till planed out.
The good news. Runs good on idle --- I've had many toys and the engine is not ruined
Also must say runs great at full speed.
My problem is the revs in between on one motor PLUS. That motor always seems to need more juice than the other to start. But it does start n like I said idles nicely

What cn I do to make the poor engine run smooth through RPMs like the other. I sincerely do not think the moor is eukered I just don't kno

Please help or wife will kill me for buying it

 

[ocod]

Hi,

I think you have the RAVE valves and usually a good place to look first.
http://www.seadooforum.com/showthread.php?37588-How-to-service-Rave-Valve-Pictorial

2nd would be fuel system.

Get a compression reading. 150 is perfect.

 

[customglassgy]

Hello Ocod , thanks very much , I will give this a try , IS this a common problem with these type of boats where one engine has mkore power than the other ?? , and is it a huge expense do you think to have a company fix this

 

[Dr Honda]

With any new toy... it's good to get a baseline on things. So what OCOD was saying is good info, but you have a pair of 720 engines... so you don't have RAVE valves. Regardless... doing a compression check is a good place to start. (so we know the health of the engines)


OK... I have a feeling your issue is a simple one. (and 2 fold)


The boat needs the pumps, and seals freshened up. Since your hole shot is bad, but they engines are still reving... you have cavitation. First, check the impellers, and wear rings. If they look OK... then the Carbon seals need replaced on the drive shafts.


Second. On the twin engine boats... they almost never run at exactly the same RPM's. Actually, on many of the seadoo boats... they run 2 different impellers. One with lower pitch than the other. That way, one will help with the low speed, and one will help with the high speed. This is exactly why they give you 2 throttle levers, and not just one. So, don't drive yourself crazy trying to get the engine to run the same speed. Once you get the cavitation issue fixed... you will push both throttles together... and then when you are at your cruising speed... you will adjust the throttles so the boat goes in a straight line.

 

[ocod]

a challenger with a 717.
Disregard the RAVE comment.



So do like the Dr said check and check other things i.e. propulsion system / throttle linkages for problems.

 

[customglassgy]

Thanks so much for answering so quickly , you guys are great and very responsive , WOW , I am super thrilled , I thought that maybe I bought a lemon , and my wife is about to kill me for spending the money that I did , Are these fixes things that I can do , ( I do understand engines but not so much jet ski engines ) ,. I'd like to fix this at my lake and not have to take it to the mechanic , not so much for money reasons but for the convenience --- Do you think that this is possible for me to do , and if so , can you tell me how to do it . Is there a way of doing a compression test with some tool I can buy . Also , I must ask , Do you think that there is any correlation between the weaker motor and the fact that it always needs a stronger battery to start ?? Again thanks so very much for he reply

 

[ocod]

Compression test super easy
just take spark plugs out and install gauge fitting.

Engine are super easy to work on.
Get a manual by joining membership or online

 

[customglassgy]

BTW - are you referred to as Doc O , my name is Frank , just exactly how do I get the compression of my machine and how do you suggest I do the other things I need to do , to get my machine running amazing , secondly can you tell me , I know you said they were easy to work on , but are they in general good vehicles , reliable and long lasting etc... in your opinion

 

[ocod]

BTW - are you referred to as Doc O , my name is Frank , just exactly how do I get the compression of my machine and how do you suggest I do the other things I need to do , to get my machine running amazing , secondly can you tell me , I know you said they were easy to work on , but are they in general good vehicles , reliable and long lasting etc... in your opinion

http://www.youtube.com/watch?v=8-kAnxzeJDg

Just remove plugs and screw in quick release adapter into spark plug hole.

Very easy if you get a manual.
Only reason for failure is human error. Its 12 yrs old to you and god know how PO took care of.

Do preventative maintenance and it will last another 12.

 

[customglassgy]

Hey Ocod , once again thanks , you really are making my life better , and I am going to order a manual right now ,
Question: do I do the spark plug test on all 4 plugs ( 2 per motor ) , I guess that is a silly question , and should it be around 150 lbs ??
Let's say the comp is Good , what would you suggest I look at next ??

 

[ocod]

Check what DrHonda mentioned.

Once compression checks out fine then other cause of poor performance is the pump.

Like said before if its new to you more than likely a few thing mechanically will need attention to insure season of no problems.

Heres a good reference for the pump removal and changing of wear ring.
http://www.seadooforum.com/showthread.php?30720-How-To-Changing-Your-Wear-Ring

You could verify throttle butterfly position but air filters have to come off to see when they are 100% open or closed.
Dr honda has write up on how to sync them. I'll try to find his thread.

If your slow off the line and one engines rpm redline but boat doesn't move could be carbon ring and/ wear ring

 

[customglassgy]

Thanks very much Ocod , you have truly been a very nice and helpful person , someone you don't find too often any more
Thanks again
I appreciate all the attention