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couple questions

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shucky

shucky

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08 seadoo gti 155 se,
I've had the ski for about 1.5 -2 years now
Anytime I start the motor I have to give it a bit of throttle at the same time while pushing the start button which in return is causing it to flood the carb ( the flooding bit has just started). it don't matter rather its just been put in the water or if I've had it running for a period of time, its a bit slow cranking over as well.
2 while riding idel mainly I can feel and hear what seems to be a serge ( eg. drops in rmp) which seems to be pretty constant.
3 the Ski seems to be ideling a bit high to me, not sure what the rpms are due to the speed-o gauges not working ( next project).
I'm just wondering if anyone else has had these symptoms and if so what was your out come result.
I've spoken to the mechanic I use for its services, due to having to connect the ECU from my ski to another ski in order to program a key for it (old key kept falling out) he seems to think the cause of that is either the ECU or main wiring harness has anyone got any thoughts on this as well.
Cheers.
Shucky
 
Lets get a compression test to see where the engine is at this point.

Someone may have played with the settings to adjust for low compression.

So again, lets get the compression readings so we can eliminate some things...
 
do you have to disconnect the ignition system or not before hand? watching vids on doing the compression test seems they may have done something to prevent the ski from actually starting?
Joe you say someone may have played around with the settings to adjust the compression, the ski is an ex hire ski from a jet ski tour biz, they made me a deal which was a bit hard to pass due to prices here. yeah I know with minor problems though hoping to sort it out.
cheers.
 
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shucky said:
do you have to disconnect the ignition system or not before hand? watching vids on doing the compression test seems they may have done something to prevent the ski from actually starting?
Joe you say someone may have played around with the settings to adjust the compression, the ski is an ex hire ski from a jet ski tour biz, they made me a deal which was a bit hard to pass due to prices here. yeah I know with minor problems though hoping to sort it out.
cheers.
Click to expand...

The fact that it is a "hire" (aka rental) ski is even more reason tondo a compression test.

Do not have the lanyard attached, cold engine, all plugs remove, spark plug wires grounded on the grounding posts if you have them. Do not add any oil to the cylinders. Install compression tool and crank. Mark down the readings and get back to us.
 
the compression results are a bit confusing, starting from the front end of the ski going backwards,
plug 1 reads 105 psi 2 140 psi 3 160 psi, while removing the plugs I noticed oil in the barrels the 2nd and the 3rd, plug number 3 plug was dripping wet with it when I pulled it I'm guessing a head gasket maybe? if that's the case does it all come in some sort if gasket kit?
not knowing until the head cover comes off, would the low compression be caused by a bad valve or the such? and can the gasket be changed without the motor being pulled out?.
End option I'm researching price wise rather getting a rebuilt engine or just rebuilding mine, hence doing things to valves and such you may as well go all out and do the bottom end of the motor as well basically.
Cheers for your help Joe. kudos to ya man.
 
Something isn't right, that much is easy to see.

Just to satisfy me a bit. Crank the engine over to clear the cylinders of moisture. Then re do the compression test.

BTW. You can charge the battery with a charger but nothing over 2 amps unless you disconnect a battery cable. And never charge with the lanyard attached.
 
will do joe, working today and Friday, not really sure how much time I'll have after hours see how I go if not I'll have to wait til the weekend. Once again, thanks for your help.
 
sounds like you may have fluid in cyl's 1 and 2. If after blowing out they don't stabilize, try adding a bit of oil to cyl 1 to seat the rings. Maybe even start it up and warm it up a bit and try compression test again, this will ensure that there is no residual oil/water in there throwing off your readings.
 
Forgot to add,,, when you do the compression test you should have the throttle on FULL THROTTLE. I believe this is what kills the spark.
 
Coastiejoe said:
Forgot to add,,, when you do the compression test you should have the throttle on FULL THROTTLE. I believe this is what kills the spark.
Click to expand...
Really? Is this a feature on the 4tec's? I thought it just increased the manifold pressure so you get a more accurate reading...
 
Thanks for replys guys .... I'll have to wait til Saturday to redo the compression test as working hours are long as here and not much daylight after getting home. I'll also post a couple pics of a few things I noticed hence easier to see the pics then to explain.
when I done the first test .... it wasn't the bottom of the plugs that where wet it was the top side say between the sleeve that slides over the sparkplugs and the cylinder hole. anyways ....I'll get back to yas Saturday Australia time with the second text results.
Just a note we're a day ahead of the U.S.
cheers shucky
 
Coastiejoe said:
.

BTW. You can charge the battery with a charger but nothing over 2 amps unless you disconnect a battery cable. And never charge with the lanyard attached.
Click to expand...
If I disconnect the battery, will that mess with the ECU memory ( ie will I have to have me key reprogrammed/flashed back to the ecu)?..
also...you say nothing over 2 amp.. I have a 2.5 amp charger.. though having no problem disconnecting a battery cable.
 
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ok I've done 2 compression tests cold engine and warm engine, cranked the motor a few times before testing each cylinder,
cold test starting from the front end of the ski,
1 100 psi,
2 100 psi <<( done twice).
3 150 psi, also tested twice.

Warm engine starting from the front end of the ski
1 130 psi
2 150 psi
3 150 psi
there is still a bit of oil on the outter side of the plugs 2 and 3, I've checked and made sure the engine oil is full as well.
 
Cold engine is correct method.

You have two holes below 120, in my opinion you are in need of engine work.

Let's let a few others offer their thoughts, but sadly, I think I am right.

I'm not saying it isn't a head issue, just saying you need to open things up.
 
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Cheers Joe, that's what I was afraid of and just as summer is starting yeah not good. Though making sure all fluid levels are full, in your opinion do you think it could last through the summer months if babied, ie taking it easy and not thrashing it on the water.? what would you say is causing the lower compression in the 2 cylinders any idea?
once again thanks for your time and help.
 
Do you know how many hours are on the engine?

With the compression at 100, I would be shocked if it even starts when in the water. It MAY start on land with no load on the impeller, but I highly doubt it will once at the ramp.

You are ALWAYS turning the impeller no matter in forward, reverse or neutral. Thus, there is a load on the engine the moment it is in the water.

The low compression can be many things. But lets try something.

Squirt some oil into the cylinder and see if the compression goes up or not. This can help isolate a valve issue or a piston issue. Normally, if it goes up the piston and rings are he issue. If it does not, it is a valve issue. But,,, if there is a hole in the piston this rule no longer applies.

Rent or borrow and scope and take a look into the cylinder through the plug hole. It may become painfully clear...
 
after buying it I had it serviced which has been done regularly even from the biz I bought it from, the mechanic I used reckons it was pushing 1000 hours, as far as putting it in the water the only starting issue is that its slow to crank over at times and you must give it a little throttle.
I'll borrow a mechanic's camara this afternoon to have a look in the cylinders... until then I'll try the oil trick you've mentioned.
cheers Joe
 
took the ski out today, slow starting at ramp, ran as usual then I shut the motor off which wouldn't start again after charging the battery it wouldn't even beep when I plugged the key in? I can hear a ticking noise beside the ecu unit( relay maybe)
 
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shucky said:
took the ski out today, slow starting at ramp, ran as usual then I shut the motor off which wouldn't start again after charging the battery it wouldn't even beep when I plugged the key in? I can hear a ticking noise beside the ecu unit( relay maybe)
Click to expand...

Sounds like a voltage issue to me.

Get the battery load tested just to see where it is. But my guess is that your ski is not charging the battery while it is running.

Test for volts while at idle and then rev the engine and test for volts again.

Idle should be 13 volts ish or better, revved should be 14 volts ish.
 
Another useful test is to measure the volts before and after starting the engine. If they don't go up at all, you're definitely NOT charging.
 
the battery test shows 13 volts dead engine, I'm not able to start the ski for some reason as I plug the key in I'm not getting the 2 beeps though the gauges light up, this is the same key I use all the time even tried the old key as well. still no beeps when plugging it in. checked fuses which seem to look ok ( not burnt or broken )
 
shucky said:
the battery test shows 13 volts dead engine, I'm not able to start the ski for some reason as I plug the key in I'm not getting the 2 beeps though the gauges light up, this is the same key I use all the time even tried the old key as well. still no beeps when plugging it in. checked fuses which seem to look ok ( not burnt or broken )
Click to expand...

13 volts dead engine is what your battery has in it,,,,

Jump the solenoid and see what happens. If it cranks, you have a good battery, battery cables, connections, starter and the engine is not seized.

No crank, and you KNOW the battery is good, then any of the items I listed above can be the issue.
 
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