06-25-2010, 08:18 PM #1
Using/burning oil and down on RPM
Noticed my ski using some oil along with being down on RPM (barely pulling 7600-7700), pulled the plugs and the rear cylinder (number 1) spark plug was dark and had visible oil on it.... I did notice that my vent tube to the stock intake from the head/block had popped off so I though I may have gotten some residual oil from that but it seemed a bit heavy to be so. I then proceeded to do a compression check which checked out fine/even with no more than 3-4 psi difference between cylinders.
At the same time I checked the plugs I also checked the charger, I could spin it slightly with my finger so we pulled the charger (checked the seal which was fine) and installed new spring washers for the clutch.
Put it back in the water today and Im still down on RPM, still getting alot of oil on the back plug ( other 2 plugs are perfectly clean and look like new). Get alot of smoke when I start it on the trailer too.
What do you guys think? Could I have a bad valve seal...... Talked to Snoman on the phone the other day and he said its very likely a valve seal but curious if anyone else had had a similar issue.... thanks in advance
06-25-2010, 09:58 PM #2
I really dont think a bad valve seal whould cause visible oil on a plug. Do a compression test and see where your at. See what shape your rings are in. How many hoursare on engine?
06-25-2010, 10:05 PM #3
Smoke on cold start is usually valve seals. Its easy enough to replace the valve seals on that cylinder and see if it helps.
06-25-2010, 11:38 PM #4
06-26-2010, 07:02 AM #5
Just try swapping the coil pack from 2 to 3. See if 2 ends up with the dark plug.
06-26-2010, 08:25 AM #6
I forgot to post/ask in my original post...... would the excessive oil getting into the cylinder be causing my loss of RPM? Could it be giving me knock retard? I know oil can severly cut down the octane rating of fuel, Im friggin stumped on this
06-26-2010, 10:32 AM #7
Since compression is fine, I would have to agree with Snoman on the valve seal ... based on what you have posted, seems the most logical. I would pull the valve cover and look very carefully with a bright light thru the valvesprings on that cylinder to see the valve seals ... might be able to see something if that seal is really bad/broke.
06-26-2010, 04:47 PM #8
Went over to the shop and ordered the valve seals today, with any luck we should have them mid week and have them installed for the weekend....... hopefully this is it.
Anyone's thought on the RPM issue being related to excess oil being dumped into the number 1 cylinder and causing some kind of knock retard issue? Obviously Im most concerned at this point with clearing up the oil issue but the RPM thing has me worried as well, it could be coincidence but both issues began at the same time so Im really hoping the valve seals fix both issues.
06-27-2010, 08:05 AM #9
Do you have the head off? I am pretty sure you will need to have the head off to replace the seals. Those seals are hard enough to get off when the head is off and there is no valve stem in the way, I can't imagine the difficulty in trying to do them with the head on, good luck if you are. Also I don't believe that is the sourse of your lost rpm's not unless you are dumping alot of oil in that cylinder!!
06-27-2010, 08:13 AM #10
The person that will be doing the valve seals is a Sea Doo tech of 15+ years( Same guy that modded Bruce's ski), he said he can swap them without pulling the head (he will use air to keep the valves up, then pull the rocker/spring/retainer to access the seals). I am dumping alot of oil, it used 1 whole quart in less than 1 tank of fuel (approximately 2/3-3/4 of a tank)
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