2006 RXP Compression Reading analysis

[kevmanetti]

Hi I read over many threads and have read that compression on supercharged skis are a little lower because there is a different ratio, however i am a little concerned about my readings.
My low oil pressure light came on today so I was afraid there may be a leak or something so I checked my compression.
From front of the ski to the back my numbers read 130/119/135.
I am not worried about the numbers being low but I am worried about the one number being so far off from the others.
Should I be alarmed or am I okay? I read it should be about 10% variance and the 16psi difference is a bit more then 10%.

 

[Coastiejoe]

Hi I read over many threads and have read that compression on supercharged skis are a little lower because there is a different ratio, however i am a little concerned about my readings.
My low oil pressure light came on today so I was afraid there may be a leak or something so I checked my compression.
From front of the ski to the back my numbers read 130/119/135.
I am not worried about the numbers being low but I am worried about the one number being so far off from the others.
Should I be alarmed or am I okay? I read it should be about 10% variance and the 16psi difference is a bit more then 10%.

You are on the boarder as far as the 10% rule goes. I would think you'd be good for the season. I would open it up and do a top end over the winter. It could be as simple as not being torqued properly. For some reason the center cylinders of engines are more sensitive to a miss-torqued issue.

Unless you have lots of hours on the engine, a top end may do what you need.

You could give it a squirt of oil and see if the compression rises a bit. If so, it is a sign that the rings are failing.

 

[kevmanetti]

Thanks for the quick reply. The ski has 215 hours on it. If it is a ring issue, the rings are replaced with a top end rebuild right? What bolts need to be torqued? I will give that a shot and see what happens otherwise you dont suggest riding it out next season? A top end sounds expensive would rather not worry about it this winter unless need be. Thanks!

 

[KK40384]

Hi I read over many threads and have read that compression on supercharged skis are a little lower because there is a different ratio, however i am a little concerned about my readings.
My low oil pressure light came on today so I was afraid there may be a leak or something so I checked my compression.
From front of the ski to the back my numbers read 130/119/135.
I am not worried about the numbers being low but I am worried about the one number being so far off from the others.
Should I be alarmed or am I okay? I read it should be about 10% variance and the 16psi difference is a bit more then 10%.

The 130 and 135 don't bother me but the 119 does. If they were all lower say 125 and 120 the 119 wouldn't stand out so much.

When the low oil pressure light came on, was it accompanied by a Pxxxx code? Reason I ask is because the oil pressure sensors have been known to fail and scare people into reading too far into a problem.

 

[KK40384]

Thanks for the quick reply. The ski has 215 hours on it. If it is a ring issue, the rings are replaced with a top end rebuild right? What bolts need to be torqued? I will give that a shot and see what happens otherwise you dont suggest riding it out next season? A top end sounds expensive would rather not worry about it this winter unless need be. Thanks!

As long as the ski makes decent power and doesn't burn oil I wouldn't worry much about it just yet. The oil pressure light is a concern though.

 

[kevmanetti]

The 130 and 135 don't bother me but the 119 does. If they were all lower say 125 and 120 the 119 wouldn't stand out so much.

When the low oil pressure light came on, was it accompanied by a Pxxxx code? Reason I ask is because the oil pressure sensors have been known to fail and scare people into reading too far into a problem.

Alright so not critical to get it done this winter? Do you think it will last another season? So far no loss in power, maybe a bit of oil loss I will have to monitor it. There was no P code. While I was riding the ski beeped and where the compass is it just said "OIL" it did this a couple times at the end of the day. The shop manual says "OIL" means low pressure.

 

[Sportster-2001-951C-Stock]

What does the engine oil on the dipstick look like, any contamination? Any engine coolant loss? Low cylinder pressure could indicate a head gasket problem and coolant could leak into the cylinder if that were the case. Check oil fill cap for signs of contamination as well, any milkshake looking residue/moisture there could be an indicator the head gasket is leaking.

Using the wrong oil can also cause low oil pressure, or the oil pressure sensor itself may be marginal.

I wouldn't get too excited over one cylinder's pressure being down a bit if there weren't other issues to confirm a problem as well, has the engine ever been overheated? Overheating can damage the head gasket.

 

[kevmanetti]

The oil on the dipstick looks like perfectly normal oil to me. If anything if may seem a bit light in color compared to what I would have thought. However No milky colors or anything at all out of the ordinary on cap or stick. Since I bought the ski 20hours ago there has been no overheating and the oil was changed when I bought it along with the front oil pump(got ruined by ceramic washers) The only issue is the low oil pressure. What is the next step to diagnose the problem? I was going to buy a new oil pressure sensor.

 

[KK40384]

The oil on the dipstick looks like perfectly normal oil to me. If anything if may seem a bit light in color compared to what I would have thought. However No milky colors or anything at all out of the ordinary on cap or stick. Since I bought the ski 20hours ago there has been no overheating and the oil was changed when I bought it along with the front oil pump(got ruined by ceramic washers) The only issue is the low oil pressure. What is the next step to diagnose the problem? I was going to buy a new oil pressure sensor.

Ahhhhh those ceramic washers...... Other than the oil pump was anything else done? Was everything cleaned out from what was left of the washers? Those little bits are notorious for clogging things up and causing oil pressure issues which in turn destroy motors.

 

[kevmanetti]

Ahhhhh those ceramic washers...... Other than the oil pump was anything else done? Was everything cleaned out from what was left of the washers? Those little bits are notorious for clogging things up and causing oil pressure issues which in turn destroy motors.

i bought it from a small shop, i was told he replaced the washers and the front oil pump and did an oil change nothing else. should i check the sensor? or what should i do next? It wouldnt help to replace oil lines would it?

 

[Sportster-2001-951C-Stock]

The oil on the dipstick looks like perfectly normal oil to me. If anything if may seem a bit light in color compared to what I would have thought. However No milky colors or anything at all out of the ordinary on cap or stick. Since I bought the ski 20hours ago there has been no overheating and the oil was changed when I bought it along with the front oil pump(got ruined by ceramic washers) The only issue is the low oil pressure. What is the next step to diagnose the problem? I was going to buy a new oil pressure sensor.

I guess the thing to do is replace the sensor and see how it goes. It's actually a pressure switch, right?

I'd kinda want to know what the actual pressure was b/c I'm curious that way, so I'd also look for a way to connect a gauge if possible. I don't know what the normal hot oil pressure for this motor should be, but general rule of thumb is minumum 10psi of oil pressure(at normal operating temperature) for every 1000RPM of engine speed for most any four stroke engine.

 

[kevmanetti]

I contacted the guy who sold me the ski. He ran a small shop. He told me "I bought it with the washers blown. I removed and replaced the front oil pump and screens. Flushed the engine, did three oil and filter changes to get the ceramic "dust". Are you getting any error codes? They have two oil sensors that are suspect. ". Is that usual standard procedure to get rid of the washers. Is there something I can do to rule the washers out. The ski has ran about 30hours since replacement. Other then the low oil pressure light just going on there is no performance issue

 

[KK40384]

Well the oil pressure sensor is a fairly cheap and easy part to replace. If you don't mind throwing a few bucks at it and replace it. If the problem goes away you're in luck. Also while you have the sensor out, screw in an oil pressure gauge and start it real quick to see what the pressure reads.

 

[kevmanetti]

Where would I screw the gauge into? The same hole the sensor comes out of? I read in manual that there is an easier place to test the pressure?

 

[KK40384]

That's what I was suggesting. If there's another place to test it I'm unaware of it.

 

[Dennis]

There is also a place at the top right rear of the cylinder head. It's a allen screw just underneath the big cooling system hose that also attaches at the rear of the head. Remove the allen screw and connect the gauge there. :cheers:

 

[AircraftDoc]

Hi I read over many threads and have read that compression on supercharged skis are a little lower because there is a different ratio, however i am a little concerned about my readings.
My low oil pressure light came on today so I was afraid there may be a leak or something so I checked my compression.
From front of the ski to the back my numbers read 130/119/135.
I am not worried about the numbers being low but I am worried about the one number being so far off from the others.
Should I be alarmed or am I okay? I read it should be about 10% variance and the 16psi difference is a bit more then 10%.

Put some oil in and check again, but don't stop there. Warm it up and then do a compression check. Could be that the rings on the piston that move around could have settled close together shortly and gave you a low reading. Before you have to do any major work, this is cheap.

I hope you have good luck.

 

[Sportster-2001-951C-Stock]

Put some oil in and check again, but don't stop there. Warm it up and then do a compression check. Could be that the rings on the piston that move around could have settled close together shortly and gave you a low reading. Before you have to do any major work, this is cheap.

I hope you have good luck.

Right, I think he's going to try attaching an oil pressure gauge and then run it(hopefully under actual hot conditions) to see how the OP is, then go from there. I don't guess the low(er) compression noted isn't the primary concern at the moment, more interested in what's going on with oil pressure.

 

[AircraftDoc]

Right, I think he's going to try attaching an oil pressure gauge and then run it(hopefully under actual hot conditions) to see how the OP is, then go from there. I don't guess the low(er) compression noted isn't the primary concern at the moment, more interested in what's going on with oil pressure.

I agree. Narrow it down. Maybe check the screens again. Something could have floated in.

 

[Sportster-2001-951C-Stock]

Something could have floated in.

That's a good possibility as well, and the new oil pump may have been damaged. Have you guys been able to find ceramic washer pieces in the oil filter element, I wouldn't know if washer pieces could pass the filter through a filter bypass but some engines have filter bypass valves as well, even a piece of washer could have found it's way into the oil pressure relief valve if there's one.

I'm not intimately familiar with this particular engine so I'm kinda following along, have noticed folks say the pressure sensors often need replacement too, I have no way of knowing what the real issues have been in the past so I should probably shy away from the conversation and just follow it.

 

[Dennis]

Yeah, SeaDoo came out with updated pressure sensors because the factory sensors were setting off false alarms. It was a common problem. I believe the new style sensors were already installed at the factory by 2006. That doesnt mean he doesnt have a bad one.
Like we've all said, he needs to check oil pressure and then go from there.

 

[Sportster-2001-951C-Stock]

Yeah, SeaDoo came out with updated pressure sensors because the factory sensors were setting off false alarms.

Sounds almost like fun times in rod bearing city.

 

[AircraftDoc]

Sounds almost like fun times in rod bearing city.

Positive waves, man. Positive waves.

 

[kevmanetti]

There is also a place at the top right rear of the cylinder head. It's a allen screw just underneath the big cooling system hose that also attaches at the rear of the head. Remove the allen screw and connect the gauge there. :cheers:

Hi dennis that is exactly what i was talking about. I believe I found the right spot. is it the little red screw in pic?

Also as you guys have stated, yes i want to narrow it down and find the cause of the oil pressure signal before worrying about compression. I am bringing the ski to a car shop tomorrow to borrow the oil pressure tester. I will see what I find then. Also how do I check the oil screens youve mentioned? Are you talking about the oil filter or is there something else?

 

[AircraftDoc]

Also how do I check the oil screens youve mentioned? Are you talking about the oil filter or is there something else?

Please goggle your year seadoo engine shop manual with the word free. I was able to download my 2004 rxp. Also get the general maintence manual. The Manual shows where, or you can wait and some of the members might be able to pull it up.