Power loss

[Jeepandski]

I have a 2005 RXP with a 2010 255 engine. I put ski in the water last weekend and noticed a power loss on the top end. It was also all over the place rpm wise while cruising at half throttle. It felt like a fueling issue. I replaced the fuel filter(which was terrible) and took it back out this morning. It was good everywhere but wot. It would go up to my normal 75-7600 rpm and stay there for a second then slowly drop down to the mid 6's like it's not getting enough fuel. Do I replace the fuel pump or is there somewhere else I need to look first.

 

[ski-d00]

The engines between the 215 and 255 are the exact same engine. The supercharger, fuel injectors, ECU, intercooler, TOPS system, pto housing, are all different. What did you use from which engine? They are not all compatible.

You should be hitting at least 8000 rpms.

 

[Jeepandski]

I didn't do the swap. They pulled everything from the 255. The entire engine, wiring harness and everything was swapped

 

[Jeepandski]

It has never been over 7600 rpm in the 3 months I've owned it

 

[ski-d00]

Well, did they switch the cluster too? I'm guessing they didn't which means they didn't switch the ECU. Post pics of everything.

Something is wrong if you aren't hitting 8000-8200 rpm when you both accelerate and reach top speed of 68 mph.

 

[Jeepandski]

I left it at the river yesterday. It will be Friday or Saturday until I can get pics. It does have a different cluster than other 05 RXP's that I have seen. Would a prop change affect the RPMs? I'm a jeep guy, when you regear it doesn't effect the engine revving. I would imagine changing out the prop wouldn't effect the engine either. The person I bought it from had just changed the prop and wear ring, he changed the pitch for more bottom end.

 

[dcm0123]

The prop will affect RPM's and speed.

A prop designed to provide better take off will give you less high end speed and allow the motor to run at higher RPM's.

You may want to see what prop was put on it to verify he did not put on a prop for speed which could end up lowering the RPM's at full throttle. May be a part number stamped on it.

If it will run at 7600 but then drops down I would continue to look for fuel related issues.

Plugs are easy to change and cheap. If you are experiencing RPM's being erratic, I would change them.

 

[MacSeaDoo]

I would pressure test your intercooler. If leaking it, it allows water into the intake which often causes issues like yours.

 

[Jeepandski]

I will definitely check the intercooler then. I'm gonna try to go get it this evening and bring it to the house. I will update as soon as I'm able to check on it. Thank all of you for the advise.

 

[dcm0123]

Easy way to check the inter-cooler- pull it out, seal one pipe end, apply 10 psi to the other and put in a 5 gallon pail of water looking for air bubbles.

Apply grease to the rubber seals so it slides easy back into the intake. If you find water puddles in the intake, good chance this is where it came from.

Use aroungd 10 PSI max so you do not damage it. This is how I found my leak.

 

[BGS]

Second: "Plugs are easy to change and cheap. If you are experiencing RPM's being erratic, I would change them."

 

[ski-d00]

Easy way to check the inter-cooler- pull it out, seal one pipe end, apply 10 psi to the other and put in a 5 gallon pail of water looking for air bubbles.

Or just pull the intake hose at the throttle body and run it on the trailer.

Apply grease to the rubber seals so it slides easy back into the intake. If you find water puddles in the intake, good chance this is where it came from

His intercooler isn't in the intake. The 255 has an external intercooler.

 

[Jeepandski]

Just to an update, I am currently waiting on a new intercooler. The old one was leaking water pretty bad. Kinda shocked it was running at all.

 

[dcm0123]

Was it an external inter cooler as noted above or did someone mix and match parts when they swapped the engine?
Glad you found this, make sure you change the oil. Might be a good idea to do it a couple of times to make sure all the water is out of it.

 

[dcm0123]

I figured I had better mention this- the attached post has an excerpt from the manual which states if you get water in your oil, they recomend rebuilding the superchargers because it could have damaged the SC bearings.

If a bearing disintegrates, the needles can cause the timing chain to break and destroy the engine.

They are not easy to rebuild unless you have a hydrulic press and invest about $100 in specialty tools.

2006 RXP full of water. Steering grommet leaked

 

[Jeepandski]

It is an external cooler. I was planning on a supercharger rebuild anyway, just due to not knowing the history of the engine and SC. I guess I'll move my plans up a little sooner. Appreciate the help.

 

[MacSeaDoo]

Amazingly these engines can still run when being fed some water through a leaky IC. If it is salt water, you will see it on your plugs with pitting.

If you have water in your oil, you would see it in the dipstick but to be honest in the water it will only leak when it runs as the JetPump pumps the water.

Most leaks are hard to detect because the pump water pressure needs to be above the intake charge pressure from the SC. Depending on the leak, this only occurs in the higher RPM ranges.

Where you get it full on though is when it is on the hose as now you are pumping water at house pressure even at idle but it takes a while. In your machine, your IC is mounted almost level with the Intake. In my boat, the IC is mounted higher than the intake.

I would swap your IC and run it unless you see evidence of water in the oil, which again I doubt it as it will burn it. (High boost engines actually use water injection to help cool and control combustion)

 

[Jeepandski]

The oil actually still looks good, I'm gonna change it anyway because I have the stuff to do it. But it's not milky at all.