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Terrible vacation with my doo

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an update and some good news! i just did and inspection on my cylinders with a video scope and saw cross hatch city! yahoo! i was able to rotate the bore scope 360 degrees and saw very very light scratches and is so light that it may be the norm and i believe it was on the exhaust side looked like you probably wouldn't tell with a fingernail run across it. the piston tops were also looking good with very little carbon which was a medium brown in color. i could still see the .25 stamp and the arrow clearly. i also pulled the crank sensor and was clean as a whistle.
next i need to buy the adapter fittings for my fuel pump pressure gauge to ck that out. auto zone should have them (dorman brand)
anything else i should check let me know. i need to find out what is causing the bog. thanks.

could it be the coil pack? how do i tell if its weak? griz? kicker? anybody?
one more question the lake near my home is 2750 ft above sea level and the lake that was much worse is
4800 ft, could that make it bog all the more?
impeller is stock and i know that higher altitudes will effect performance but not this horrible bog. thanks
 
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Higher altitude will tend to make the air/fuel mixture richer, but the MPEM could compensate for that if there's a manifold air pressure snesor in the system (I haven't looked at the schematic to see if there's one).

If your plugs haven't been changed since the initial startup then you might want to change them, hopefully you did that already at the campsite. If an old motor being replaced didn't blow up and contaminate the plugs (many engines I replace are cracked due to lack of winterizing) then for the first fire I run the old plugs b/c I know there's probably s-tons of assembly lube waiting to coat the plugs with who knows how much zinc and molybdenum, etc.?

All that aside, Always replace plugs as the first step troubleshooting a bog, not that I think there's a problem with them but b/c I've fixed quite a few ill-running 2-strokers just by changing the perfetly-fine looking plugs with fresh ones. If this doesn't take care of the problem then switch back to the used ones and keep the new ones handy for next year.

So yes, A+++ on changing plugs.

While you've got your head in the bilge take a peek at those connectors on the various sensors, so many of them are all the same I think it's possible to connect almost any of the goes-inta's into the wrong goes-outta's. Normally the MPEM would catch something like this by giving at least a disapproving beep and not revving over 4500 RPM but hey, who knows?

Since the issue was there in the first place but got worse, could be whatever's wrong is decaying quickly or the MPEM's TPS calibration changes amounted to turning the "knob" in the wrong direction. The base TPS position is probably a part of the accelerator enrichment, so if the MPEM isn't enrichening on TPS that could lead to a lean bog.

But there are other things that could go wrong in the sensor department, such as if the MPEM's manifold pressure sensor goes-inta' was actually reading the engine temp sensor and/or vice-versa? Or maybe even one of the sensors kicked the bucket (service manual has info on measuring them via ohmmeter/voltmeter from the MPEM end of the harness).
 
Kevin, been up for a while pondering your issue. Just verified on mine, the TPS and the APS have the identical connector (3 wire)....worth a double check on the wiring schematic for the color combination. Have you gone back and ohmed the sensors? Just some early morning thoughts.
 
Silly question, but do these engines come with a rebuilt RV housing & a fresh valve installed & timed?
I know the RV valves can raise havoc with lower RPM performance. I assume this is all part of a std rebuild from the "big three" but figured it was worth asking at this point.

I agree with the compression. even if it was a little low, it shouldn't cause these issues your having, so you can look past that IMO. HHhmmmmmm.

Also, was this a project ski from the beginning? I don't remember if it was purchased in good running condition. Could be something that was messed up before you got it? My RXDI has been an absolute nightmare of backwards problem solving from things done to it by the previous owners. Monkey'd with at every level imaginable....
 
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make sure on the battery and charging system,
hook a voltmeter up with test leads, so you can look at it when riding in the water, also , 55 - 60 fuel pressure and this is when riding it, just pull seat back and you can see when riding it, take some duct tape and secure both voltmeter and fuel pressure gauge, when it bogs, something will change most likely ...
they dont fail often in skis, but the stator does some weird stuff in the sleds..
i put a stator in mine before
where are your raves set at ??? try setting them flush, all 3

seems to me a bog from fuel, but, they have been playin with tps, and it change to the bad, then it changed better, if it is set proper, i would lean on fuel pressure ...

you can take a voltmeter, and probe your tps and watch the voltage change, ground black lead of meter, you have 3 wires, 1 is ground, 1 is 5 volt supply wire, 1 is signal wire back to mpem, the 5 volt wire will read around 5 volts all the time, then the signal wire, will change when you them the throttle, watch it change slowly, if there is a dead spot (a no voltage all a sudden) then tps would be bad
 
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@ragtop. yes it was a project ski from the beginning. and ses installed anew rotary valve and my cover so im sure he checked for clearance.
[MENTION=42312]GRIZ[/MENTION] thank you i will re read your post and try these thing out, im at work now lol! thanks again.
 
griz, i have the raves and water valve set flush. i tried the nickle dept thing on the raves only and didnt help.
as for the volt test on the tps, do i probe the wires that go to the tps? if so i need some decent probes so i can free my hands lol.
also would it make a difference weather i hooked the fuel pressure gauge inline at the fuel rail or the pressure regulator?
 
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you can make up some leads with little alligator clips,and a hat pin will backprobe connector, (i make em up with singer sewing machine needles and use jump wires with alligator clips) i made these up alot through the years, electrical and fuel systems is my primary job with chrysler, as far as the fuel pressure, yes, its ok to do there, but at the rail is the easiest to hook up ...
to me, i believe now, that your tsp is correct, and issue is with fuel pressure, or charging system, if it will slowly accelerate all the way up, without an issue, i would say tps is ok, on a hard acceleration, it bogs, i would say the supply of fuel just aint there, but, only way to see is hook up, meter and fuel gauge and hit the water, in 30 plus years wrenching, i probably drove vehicles, across usa with fuel gauges on em
 
it bogs bad no matter if i accelerate hard or easy from a dead stop or doing 30mph and the punch it and still bogs bad.
how to tell if it may be a fuel pump or fuel pressure regulator issue?
 
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have to drive it with a gauge hooked up, hook a meter also, and check and maybe eliminate 2 different things ...
 
Kevin, been up for a while pondering your issue. Just verified on mine, the TPS and the APS have the identical connector (3 wire)....worth a double check on the wiring schematic for the color combination. Have you gone back and ohmed the sensors? Just some early morning thoughts.

wow man, i didn't mean for you to lose sleep, but thanks! lol! j/k anyhow, i just checked with my manual and confirmed that the plugs are in the right spot as per color codes. yes i think it would be a great idea to go back and test all the sensors. i have nothing better to do till i get the one part needed to hook my fuel pressure gauge inline to test for pressure. now get some sleep bro! hahaha.

edit: i got to thinking as i was reading my repair manual, if i had a bad sensor, would it send the maint light on producing a fault code? ive got to get a candoo lol!
 
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Higher altitude will tend to make the air/fuel mixture richer, but the MPEM could compensate for that if there's a manifold air pressure snesor in the system (I haven't looked at the schematic to see if there's one).

If your plugs haven't been changed since the initial startup then you might want to change them, hopefully you did that already at the campsite. If an old motor being replaced didn't blow up and contaminate the plugs (many engines I replace are cracked due to lack of winterizing) then for the first fire I run the old plugs b/c I know there's probably s-tons of assembly lube waiting to coat the plugs with who knows how much zinc and molybdenum, etc.?

All that aside, Always replace plugs as the first step troubleshooting a bog, not that I think there's a problem with them but b/c I've fixed quite a few ill-running 2-strokers just by changing the perfetly-fine looking plugs with fresh ones. If this doesn't take care of the problem then switch back to the used ones and keep the new ones handy for next year.

So yes, A+++ on changing plugs.

While you've got your head in the bilge take a peek at those connectors on the various sensors, so many of them are all the same I think it's possible to connect almost any of the goes-inta's into the wrong goes-outta's. Normally the MPEM would catch something like this by giving at least a disapproving beep and not revving over 4500 RPM but hey, who knows?

Since the issue was there in the first place but got worse, could be whatever's wrong is decaying quickly or the MPEM's TPS calibration changes amounted to turning the "knob" in the wrong direction. The base TPS position is probably a part of the accelerator enrichment, so if the MPEM isn't enrichening on TPS that could lead to a lean bog.

But there are other things that could go wrong in the sensor department, such as if the MPEM's manifold pressure sensor goes-inta' was actually reading the engine temp sensor and/or vice-versa? Or maybe even one of the sensors kicked the bucket (service manual has info on measuring them via ohmmeter/voltmeter from the MPEM end of the harness).
on the maiden startup i used the old plugs as like you said lots of assembly lube, the on the maiden ride on the lake i put a set of new plugs in. at the lake of the maiden voyage, i left the ski strapped to the trailer and fired right up, let it run a bit while checking for leaks and such. then launched it and let it idle out a few to let it warm up then gave her a little gas to get to plane but died and was very hard to start which took several tries till it finally took off and it ran great for 30 min the gave it a rest for 30 min, during that time i put the original plugs that came with the ski when i bought it back in, started right up and ran great for the next 30 min and so on. if i remember right it did have a bog at take off from the beginning but wasn't so sure as i was breaking her in and didn't want to push it. the following week pretty much the same. after those to times out i clocked 4 to 5 hours on it and ran 11 gal of gas. the 3rd time out i was varying the throttle up to 90% noticing a 2 to 3 second bog at take off. other that that, it would have plenty of power thru out. on that day i installed the newer plugs back in and then it was very hard to start but only for that one time. rode it for another hour then was done for the day. had the tps reset by dealer no1 installed brand new plugs to be ready for the camping trip, well you know the horrible story. yes i did try the other 2 sets of used plugs i had with me and made no difference. i did verify that the sensor connectors were right as per manual color code. thanks.
ps i did buy 2 new sets of plugs today:)
 
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Sounds like you've swapped in enough plugs to rule out that possibility, plug conversation is dead horse now.

I think if you have a bad sensor the MPEM won't always in every case report a fault, S/W engineers like to keep us guessing sometimes. I had one last week(not a seadoo) that wouldn't report faults, then began reporting a number of different faults on each restart a different fault appeared, then wouldn't restart. Apparently the s/w couldn't determine which sensor it couldn't trust, noticed the scanned MAP sensor value was out in left field. Turned out it was a bad computer, one of the I/O channels was bad.

Here's one for ya: The 951 DI had a couple of different intake/exhaust port configurations depending on year and if mismatched with the wrong MPEM fuel map/cylinder combo, would also bog/hesitate.
 
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well i just retested all the fuel system sensors and all checked out ok, i guess the only other thing now is to check the fuel delivery. need to
re-buy the adapter parts needed for my fuel pressure gauge as i got the wrong size, i thought it was 5/16 and turns out i needed 3/8" :(
i want to get this figured out so i can take out this weekend, going camping .
 
If you make up a test gauge & tee it in, hopefully you can set it up so you can watch the pressures as you ride it in the water.

It would be nice if you had another RFI ski to swap parts with.
 
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yep im making a tee for that reason so i can ride it.:) i'm hoping that i didnt ruin seals in the metal tube that hooks in line with the fuel pump and regulator as i had it upside down a few mo ago and are slightly different size's
i will do a leak down test as well. but its gotta be fuel delivery and everything ck's out good.
 
i finally got the parts needed to ck the fuel pressure and reads 62 psi on the trailer while running and 56 not running spec show 56 to 60 psi and the manual states if too high replace the fuel pump module. meaning the whole baffle! is the 2 extra psi something to be concerned about? is it why the bog at take off? if it is a problem would that be the pump or pressure regulator?
i probably wont be able to test the fuel pressure on the water till this weekend when i go camping. if that is all good what else can it be?
 
i finally got the parts needed to ck the fuel pressure and reads 62 psi on the trailer while running and 56 not running spec show 56 to 60 psi and the manual states if too high replace the fuel pump module. meaning the whole baffle! is the 2 extra psi something to be concerned about? is it why the bog at take off? if it is a problem would that be the pump or pressure regulator?
i probably wont be able to test the fuel pressure on the water till this weekend when i go camping. if that is all good what else can it be?

i will also add that the fuel pressure held at 52 psi for 20 min after i shut her down and and held at 40 psi for over an hour. pretty typical right?
 
I wouldn't think a couple LBS high is going to make a difference? But, I would still water test it to make sure you still have the 60Lbs when its acting up. You might also want to check your gage on an airline against another known, accurate gage to make sure its the same. If it was me, I would now be pulling the RV cover & checking the timing & make sure its the correct one for your ski. It certainly should be correct, & SES does rebuilds everyday. I would think they have a process that makes sure its correct every time. But Humans still goof up sometimes. Did you happen to checking the ignition timing? That can take a little time to do, but your running out of things to check.

Holding the pressure is good news! It means you have a healthy check valve in the pump & you injectors are not leaking.
 
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Yea, those two extra pounds could be a small calibration issue. If it was like 10 - 20lbs high, then I'd suspect that your fuel pressure regulator has gone bad. Rest easy if it's only off by 2lbs.
 
thanks guys, if i can there may be a small chance that i will take her to the lake after work tonight to see if the fuel pressure holds up. if that is good, sounds like the rotary timing may be a issue, ive seen so many post on that with the research i've done. as far as ignition timing, that can be tested and done with a candoo pro right? im going to get one asap.
 
I think the timing would need to be pretty far off (retarded) to create a bog. If you have a dial indicator, you could follow the flywheel marking procedure & see where it is right now without the candoo. I am not certain of the specs on the RFI, but I don't think the MPEM advances the timing more than 2 degree's at idle. I just went through this with MY RXDI as I have been chasing a strange gremlin with it. (I'll post about it when I get it figured out) ;)

My first skis where a pair of 1992 580's One of them I installed an engine from a 1989 SP, but used the ignition, carbs & everything else from the 1992. It ran good, but had a hesitation if I pinned it from idle. Turned out the 92 used a wider valve opening & slightly different timing. Bought the correct valve on ebay, retimed & the problem was gone.

I would say the likelihood of SES goofing up is low, but at this point you pretty much have to look at it & its easy to do. Be carful though, when you pull the RV cover off, the valve will want to come off with it. Then you will not know where it was timed! Pull it back very slowly, & if you need to, separate the valve from the cover & slide it back to the case. Make sure you check not only the timing, but that it is the correct valve for the engine. I might still have the paper cut out pdf timing wheel if you need it. Its floating around on this site somewhere tho.....
 
pm sent also -- here is a chart for settings, and some people get in a hurry, and set things wrong sometimes
http://www.seadoosource.com/rotalign.html

if you check it, set it on a degree wheel and check first that the rotary valve is a 159 deg valve first, then set the valve properly

i know they also have 147 and 132 degree valves, not sure what they fit though
 
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