Double trouble

[Brprxt215]

Hi guys I am having two small issues. 1st issue is within the first 5 minutes of starting and idling out of the channel to the lake my 96xp will “bog” in a sense even at WOT and go no faster then idle speed. I’m thinking it’s a rectifier issue but once it does it if I let off throttle for ten seconds and hammer it again it clears up and doesn’t do it the rest of the day. I can fall off and it starts right back up. That’s why I’m confused. If it was rectifier wouldn’t the charging system stop? Or can it be that intermittent thing and goes back to working after that clears up? Last summer it did this to me when water testing on trailer so I put in a crappy Chinese eBay rectifier and it made the problem happen all the time. So I put the old one back in and ohm tester the connections inside the stator and everything ohmed out where it should. I’m just wondering should I just try a new rectifier from osd before trying a new stator? I have not checked voltage while it’s running this year but it was fine last year when I checked it. My second issue is with the trim. It worked on the trailer, gauge and nozzle. I put in a trim doctor trim fix module. I just rechecked all connections and they seem ok but when I press the start/stop button the gauge kicks on but the motor doesn’t move. Checked the fuses in the ignition box and they are not blown. I pull the trim motor off the worm gear and still have no movement. I then disconnected the motor and hooked the motor directly to the battery and it goes both directions so the motor is still good. Is there anything in the grey box related to the trim or maybe I have a messed up connection in the hood since I know everything pigtails off the info gauge? Any ideas would be greatly appreciated thank you!

 

[Sportster-2001-951C-Stock]

A quick rectifier test is to temporarily disconnect the red output wire of the rectifier and see if the ski runs normally while it's disconnected. Can't leave it disconnected long b/c the battery will not be charged so eventually it runs down.

I think you need to confirm there's power and ground to the control module of the trim system, there may be a fuse or relay inside that's gone south?

 

[Brprxt215]

A quick rectifier test is to temporarily disconnect the red output wire of the rectifier and see if the ski runs normally while it's disconnected. Can't leave it disconnected long b/c the battery will not be charged so eventually it runs down.

I think you need to confirm there's power and ground to the control module of the trim system, there may be a fuse or relay inside that's gone south?

Yes I have heard about unplugging red wire. Its just confusing as it only happens one time in the first couple minutes of running then doesn’t do it the rest of the day. And I assume the battery is staying charged or else it would not want to start after falling overboard and hopping back on but it starts right back up. As far as the trim when you say controlue module do you mean the trim gauge itself? I did not pull out a volt meter today just did some visual tests on the connections and made sure motor was still good. I just set it in the middle for the time being until I decide to dig deeper

 

[Sportster-2001-951C-Stock]

If the battery is being overcharged, this will cause the CDI ignition to malfunction. I don't recall if my 95 used just a rectifier or if it had the regulator/rectifier but older skis used to just have a rectifier so this design didn't regulate battery voltage. The newer systems using the regulator will overcharge the battery and cause CDI problems.

But since this only happens in the 1st several minutes of operation, perhaps there are other reasons not related to ignition system, such as excess crankcase oil to burn off from a leaky crankshaft seal? I think you might see excess exhaust smoke in this case. Or perhaps you have a carburetor issue with the fuel metering needle sticking open causing excess fuel at low speed and it loosens up after a few minutes.

 

[Sportster-2001-951C-Stock]

When you say BOG, does this mean it's pig rich on fuel, lean hesitating, or is it more like an ignition miss occurring?

The electric trim motor is connected to the control module , the box that powers the electric motor.

 

[Brprxt215]

If the battery is being overcharged, this will cause the CDI ignition to malfunction. I don't recall if my 95 used just a rectifier or if it had the regulator/rectifier but older skis used to just have a rectifier so this design didn't regulate battery voltage. The newer systems using the regulator will overcharge the battery and cause CDI problems.

But since this only happens in the 1st several minutes of operation, perhaps there are other reasons not related to ignition system, such as excess crankcase oil to burn off from a leaky crankshaft seal? I think you might see excess exhaust smoke in this case. Or perhaps you have a carburetor issue with the fuel metering needle sticking open causing excess fuel at low speed and it loosens up after a few minutes.

There is a little excessive smoke in the first several minutes but I figured that was just a two stroke lol it might be a leaky crank seal but there’s never any oil down in the hull or anything. And it’s not really a bog it was just the best way I could describe it since I can’t post the video. The carbs were freshly rebuilt by a guy highly recommended on the seadoo page on Facebook.

 

[JeremyD615]

I’m kinda leaning towards a slight leak at the crank seals as well, but I’d try a known good rectifier first. The aftermarket ones can do some funny things, even new...

 

[Sportster-2001-951C-Stock]

Yes, at startup and while still cold you might notice slightly more oil smoke, as combustion temps are low and while sitting stone cold oil tends to run to the bottom inside the crankcase. So maybe yours is normal and not oil flooding.

Could be your idle mixture is slightly lean, especially if the engine stalls flat like it ran out of fuel.

If it's on the rich side though, some four-stroking begins to occur and in this case the motor isn't prone to stalling flat but you have to apply throttle to keep it going, to clear out excess fuel by adding air to the mixture in the crankcase.

Also, a cold engine will need slightly more fuel than a warm one, so maybe it's just warming up?

Try briefly blipping the choke while it's acting up to see if the issue clears up right away or gets worse. Blipping the choke will add fuel so if there's already too much the issue will be made worse.

If there's not quite enough fuel, blipping the choke will improve it or could tip it to overly rich depending on how long you apply choke. So pay close attention

I guess 5~10 minute hot (heat soaked) restarts are easy. To me this is an important metric, like a benchmark goal for idle mixture adjustment. Not too rich and not too lean, for the sweet spot. just blipping the starter for maybe 1 or 2 crank revolutions and she's fired up, is perfect. If not, idle speed mixture might need some adjustment.

If while riding at idle the RPM begins dropping (trending down), and to keep it from stalling you have to blip the throttle and hold it open a few seconds, this is called "clearing it out", indicative of a slightly rich idle mixture that builds in the crankcase and additional air is necessary. Usually this is accompanied with 4-stroking.

If the opposite happens, ie: idle RPM is trending down and blipping the throttle results in an immediate stall like it ran out of fuel, this indicates the idle mixture is too lean. This is lean hesitation.

If you detect slight or occasional but not constant 4-stroking, this is better than no 4-stroking at all b/c if there's no 4-stroking the mixture is on the lean side of the sweet spot and prone to detonation, which can roast the piston.

Maybe this explanation can give you some ideas of which way to go.

Here's a demonstration of rich 4-stroking:

An additional description of 4-stroking:

 

[Sportster-2001-951C-Stock]

I’m kinda leaning towards a slight leak at the crank seals as well, but I’d try a known good rectifier first. The aftermarket ones can do some funny things, even new...

Definitely need a good regulator if this model is the regulator type. The reason is, aside from destroying a good battery, the CDI is very sensitive to system voltage. Too high or too low and they stop firing.

 

[Brprxt215]

Yes, at startup and while still cold you might notice slightly more oil smoke, as combustion temps are low and while sitting stone cold oil tends to run to the bottom inside the crankcase. So maybe yours is normal and not oil flooding.

Could be your idle mixture is slightly lean, especially if the engine stalls flat like it ran out of fuel.

If it's on the rich side though, some four-stroking begins to occur and in this case the motor isn't prone to stalling flat but you have to apply throttle to keep it going, to clear out excess fuel by adding air to the mixture in the crankcase.

Also, a cold engine will need slightly more fuel than a warm one, so maybe it's just warming up?

Try briefly blipping the choke while it's acting up to see if the issue clears up right away or gets worse. Blipping the choke will add fuel so if there's already too much the issue will be made worse.

If there's not quite enough fuel, blipping the choke will improve it or could tip it to overly rich depending on how long you apply choke. So pay close attention

I guess 5~10 minute hot (heat soaked) restarts are easy. To me this is an important metric, like a benchmark goal for idle mixture adjustment. Not too rich and not too lean, for the sweet spot. just blipping the starter for maybe 1 or 2 crank revolutions and she's fired up, is perfect. If not, idle speed mixture might need some adjustment.

If while riding at idle the RPM begins dropping (trending down), and to keep it from stalling you have to blip the throttle and hold it open a few seconds, this is called "clearing it out", indicative of a slightly rich idle mixture that builds in the crankcase and additional air is necessary. Usually this is accompanied with 4-stroking.

If the opposite happens, ie: idle RPM is trending down and blipping the throttle results in an immediate stall like it ran out of fuel, this indicates the idle mixture is too lean. This is lean hesitation.

If you detect slight or occasional but not constant 4-stroking, this is better than no 4-stroking at all b/c if there's no 4-stroking the mixture is on the lean side of the sweet spot and prone to detonation, which can roast the piston.

Maybe this explanation can give you some ideas of which way to go.

Here's a demonstration of rich 4-stroking:

An additional description of 4-stroking:

Thanks for all your help. This ski does not have a choke it’s been converted to primer by previous owner. I’ll try these methods out and see what I get maybe it is just loading up on oil at cold start ups. I would just like to get these two issues fixed before next Saturday. I’m supposed to compete in my first watercross event ever and don’t want to be at the line and not be able to go lol

 

[Sportster-2001-951C-Stock]

At least you know what you've got now, if you go tearing into it you need to have time to correct for any setbacks.

As long as it runs strong once warmed up you should do the event first, IMO.