2002 RX DI... 110psi & 25psi ..likely cause....

[vwmikey99]

I just picked up a 2002 Seadoo RX DI, as my project.

I have not taken her apart yet..but I am wondering if anyone has had some similar situation...and what had to be replaced.

It has 99 hours on it, 110psi in the back cylinder, and 25psi in the front cylinder.

I'm wondering...what is the common cause of this? faulty oil pump? how would I test the oil pump on a non running machine?

Being that the one cylinder has 25psi,is it likely that the rest of the motor bearings are cooked because of oil starvation, or am I likely good to go with a set of pistons, rings, and gaskets...?

thanks in advance
Mike

 

[timmyboy76]

throw'n a bone..

i'd say, remove what you can to give urself a better chance of looking down into the bottom, without actually tearing whole thing apart. The oil cable would be a simple lookover, making sure its moving while throttling, but not knowing these DI machines, i'd say, a fuel injector/direct injector..whatever delivers the fuel..didnt deliver on the pto side..? Since its sounds like a topend only, with botth barrels removed, because the base gasket is 1, you'll have a great shot, taking a gander at jounals and rods..:cheers:

 

[vwmikey99]

I had a look through the rave valve, and moved the piston around a few times. It looks like the front cylinder (closest to the front (25psi) #1 ran really dry, cylinder wall is scored up compared, an the rear cylinder (pto, 110psi) looks like it had lubrication on the piston walls) and with a boroscope the rear cylinder actually looks pretty good.

Any idea what the common problem on one of these is to starve it of oil/fuel?

I have heard the oil pumps almost never go on these, it does look like the lines are in place..hard to tell if they are moving freely though.

 

[vwmikey99]

the MAG (front cylinder) the piston rings are pretty much welded to the piston.

The MAG cylinder is scored up..but can be saved with a some emery cloth and a hone job. The PTO cylinder looks great.

I've ordered the pistons, rings, needle bearings, etc... I am just wondering what the common problem is when this is the symptom (30psi MAG, 125psi PTO).

I dont want to put my new pistons in, close up the motor..and then blow it up in 30 minutes.

Can the DI machines run premix style?

 

[timmyboy76]

think its more of a fuel injection problem, than lube problem. Inspect the oil line going to that side and its fitting, make sure it aint clogged, other than that, the pump just pumps, not more to one side than the other.

 

[ski-d00]

I've rebuilt many DIs and the most common reason for piston failure is using cheap oil. Using wrong oil on the DIs will mean almost certain failure. The DI motors use very little fuel(about 30% less than the carb version) and rely heavily on the oil for cooling and lubrication. The oil pump systems are very very reliable and many people blame the oil pump system for all their problems when it is usually elsewhere. The fuel injection/air injection systems are also very reliable(fuel pumps not so much).

Remove the cylinder and see what you have, you may be able to just get away with a top end job. Verify that it has the correct oil in it. Do not mess with the throttle body setting as it is virtually impossible to reset unless your an expert.

 

[vwmikey99]

okay..so I got down to a point where I can see the oil lines. it would appear that there are bubbles in them. any suggestions?

 

[ski-d00]

Bubbles can mean that someone ran it out of oil and then put oil in it after the fact. Or, they used the wrong oil. It is very important to get the air out by bleeding the system with the bleed screw. In fact, I'd purge all the old oil and put new xps synthetic in it if it were me.

You may be ok with just a top end depending on how hot the crank got and how much metal got down in the crank. Post pics when you get the cyl off.

To answer some of your earlier questions...

No, you can't run premix on the DIs, not even for break in. It will cause problems with the fuel injectors.

Yes, it is simple to test the oil injection pump with a non running machine. Take it off the mag cover and spin it with a drill(make sure it's primed first).