Seadoo Utopia will not rev past 1000 rpm

[leomonaghan]

While traveling across the lake at about 40mph the boat suddenly lost power. I returned to shore slowly as the engine would not pass 1000 rpm
Replaced spark plugs and high tension leads and checked the spark
Compression was good in all cylinders at 8.4 to 8.7 bar. (125 psi)
Fuel pressure was 43psi
Throttle position sensor is giving erratic readings and I have ordered a new part
[video]http://m.youtube.com/watch?v=VraKu750xA4[/video]
Cleaned out the old fuel and replaced with fresh fuel
Cleaned out the old oil and replaced with fresh oil
While I am waiting for the throttle position sensor to arrive does anybody have any further advise?

 

[Dr Honda]

I know we were talking a little on this in the Premium section.... but did you ever locate the throttle guardian?


Did you already buy a throttle position sender?


From your video... it seems like the engine is in a protected mode. (the ignition is dropping out to keep the RPM down) You may want to take a trip to a local Mercury dealer, and have them plug into it, and see if they can pull any codes.



JUST FOR A TEST>>>>

Close to your ignition coils... there is a black/yellow wire. This is the "Kill" wire. Disconnect it at the plug close to the coils. If it will rev up... then either the Guardian is bad... or the main computer is keeping the RPM's down. BUT... DO NOT run the boat with that wire disconnected. It's the safety, and the rev limiter. (so open the throttle VERY easy on the test, and do not over-rev the engine)

 

[leomonaghan]

Using the photo of a throttle guardian from eBay I have searched the entire boat and I cannot find it. From a previous thread it said that the supply to the guardian comes from a yellow/ black wire from the ignition key switch. I cut this wire but the engine still did not pass 1000rpm

I followed the wiring loom from the fuse board under the helm looking for the guardian. A branch went to the throttle lever. I removed the throttle lever and tested the neutral switch and it was working properly.

I had the boat with a dealer and he diagnosed that the throttle position sensor was giving erratic readings. He has the sensor on order and it will be in next week. He does not have the correct test lead to connect to his laptop. I have brought the boat home while we are waiting for the sensor

I have checked around the coils for a black/yellow but I did not find such a lead. I found a black\yellow at ECU and I cut this but the engine still did not pass 1000 rpm.

I am currently trying to find a dealer with the proper test equipment.

 

[Dr Honda]

Well... a previous owner may have already removed it.

I'm going to look over the wiring for your engine... but with the prob you are having... you need hooked to a DDT computer. It will tell you exactly why it cutting out.

 

[Dr Honda]

I dug though the manual for your engine... and one of the diagnostic issues is...


If Engine is restricted to idle speed:

1) Failed TPS
2) Battery voltage below 9.5v


So... are we sure the battery is OK? Put a meter on it, and check while it's running. If it's OK... then it looks like the TPS is most likely the issue. But the manual also recommends checking the system with the DDT. (Mercury's scanner)


Let me ask you this... are locked into the TPS that your other mechanic is getting? If you want to try to change it yourself, I have a new TPS for your engine at my shop. I bought it to see if it could be adapted to the older 240 engine. (the old style TPS is almost $500 !!!!) If you are interested... I will sell it to you for $90 USD, shipped. (that's about half price)


The only reason I asked is because you said you are looking for a different shop.

 

[mrmetro]

Dr. Honda, do you still have that TPS?

 

[Dr Honda]

Dr. Honda, do you still have that TPS?

Yep.

PM me if you want it.

 

[mrmetro]

Dr. Honda...I sent you a PM