96' XP will not hot start condition

[1983]

The thing is when you are not the original owner a lot of unknown things can happen to the machines

I agree



Rob

 

[1983]

How does this look ?

None of them are deep at all, should I swap it? There is some circular marks which is to be expected.
.012 clearance. I can't even force a .013 feeler in there.....

 

[mikidymac]

It honestly doesn't look that bad.
Can you feel any of the gouges with your fingernail?

 

[1983]

It honestly doesn't look that bad.
Can you feel any of the gouges with your fingernail?

I honestly can't feel any of the marks with my nail, my nail just glides over em

Rob

Can anyone post a picture of the razor blade over the lever arm in 787 carbs when setting up needle/seat arm height and pop off.

I wanna make triple sure I've got it correct.

Thanks everyone
Rob

 

[racerxxx]

I'll say it's not the best but should work fine. I'm deff not a fan of the wear at the top of the ports on the case nor the rust stains on the RV surface. That was rust at one time that got polished off, wonder what the back side looks like. I have seen those same black stains on some of my engines i have torn down that had rust on them----exactly the same. It almost looks like it was run low/dry on oil a time or 2.



Look at the top of the port, you can see the wear

 

[1983]

Gonna take a second look at that port entry tomorrow.

Do you think this RV assembly as pictured would cause hot start issue? [MENTION=57920]racerxxx[/MENTION]

 

[benjilafouine]

Sink it!!!! (joke).

Question is: did the problem evolved slowly over time or it started suddenly? RV cover can also play a role (so I was told by an incompetent mechanics last year...).

RV stuff would not happen suddenly IMO unless something go stuck into it.

Benji.

 

[1983]

This pic is from the manual page 06-03-5.

Is this how you all setup your lever height? Flush with the metering chamber floor? Or even lower because of the diaphragm red nipple/button possibly pushing on lever and opening needle/seat.

I ask because I set mine up like this and I guess we are back to carbs being issue since RV clearance passed at exactly .012 ( factory spec )

I opened up what I believe to be a set of carbs that has never been touched before, tempo lines and oteiker clamps intact all screws still painted black, and for fun I checked pop off and bleed down. It was 17-18 psi pop off and bleed down test passed with wd40 as lubricant. These were off a freshwater 96 gtx I have. Now I looked at the lever arm and it is set much lower, almost 1/8" below metering chamber floor in both carbs. Is that how low they should really be set??

 

[1983]

Funny story, this is a salt water ski prior to my ownership. On the first ride last season about a mile from dock it started to bog down and feel heavy and sluggish. Exhaust thru hull hose clamp had been rusted and snapped. Picture a big hole in hull below waterline lol. So water filled the engine compartment through the exhaust thru hull fitting and my buddy towed me back. By the time I got the truck backed down the ramp water was up to handlebars so pretty much sunk it.

This was on the first engine, not the current engine.

Sink it!!!! (joke).

Question is: did the problem evolved slowly over time or it started suddenly? RV cover can also play a role (so I was told by an incompetent mechanics last year...).

RV stuff would not happen suddenly IMO unless something go stuck into it.

Benji.

 

[mikidymac]

Those cases do look saltwater nasty.
The lever should be flush with the top of the chamber like in the manual but it is ok to bend it up or down a few mm to get it exactly where you want the pop off. I do it to try to get both carbs as close to each other as possible. If you go to far down it will not open correctly and to high it will not close. Your final leak-down test with everything back together will tell you if the diaphragm is holding the lever down because it will not hold the 10 psi.

Did you happen to check that engine for air leaks before you tore it down. That rotary cover surface and o-ring look pretty nasty and that is a prime area for air leaks.

 

[1983]

EDIT: I think what you are seeing in the first pic of RV cover is my marine grease I put on new o-ring. It probably looks like crusty old paint or something on the o-ring in picture. The grease is pennzoil brand and is a off yellow color.


This is a different engine than what came in this ski when I got it, from my knowledge this current engine only saw saltwater a few times years ago and has been in fresh since. But who knows. I didn't think the cases looked that bad, no crazy gouging. Oh well, who knows what the issue is. I appreciate everyones input.

The levers are currently set at flush and the carbs do pass the psi test. Ive pumped them up to 20 psi and they hold with diaphragm and cover assembled. I just can't figure out if maybe when fuel is in carbs and ski has been running and is warm its a different environment in there and diaphragm is causing needle and seat to open slightly. I've cranked it up at idle and checked multiple times for fuel dribbling into carb throats and there isn't any. It all looks normal while idling.

The only thing i've torn down on this engine is I replaced the cylinder/jug rubber head o-rings for peace of mind, and torqued head. Then I removed the RV cover and installed a new o-ring with grease weeks ago. Then put engine in.

I haven't put on block off plates and checked for leaks. But this hot start was a common issue among the multiple engines this ski has had. I thought for sure with a whole different set of carbs fully rebuilt and passing all psi tests it would have fixed problem.


Rob

Those cases do look saltwater nasty.
The lever should be flush with the top of the chamber like in the manual but it is ok to bend it up or down a few mm to get it exactly where you want the pop off. I do it to try to get both carbs as close to each other as possible. If you go to far down it will not open correctly and to high it will not close. Your final leak-down test with everything back together will tell you if the diaphragm is holding the lever down because it will not hold the 10 psi.

Did you happen to check that engine for air leaks before you tore it down. That rotary cover surface and o-ring look pretty nasty and that is a prime area for air leaks.

 

[mikidymac]

If this ski has had the same hot start issue with different engines then I would look at the fuel system and tank as well as the electrical parts in the box.
We used to have Kawasaki 550,s back in the day that world run fine cold but after the CDI boxes would run for a while and get warm then run bad and not restart until they cooled. Faulty electrical parts get worse with heat when the resistance goes up.

 

[1983]

I removed the tank ventilation system last night, I checked the down low bow line port side one way valve, it releases right at 1.5 psi per spec. Then the black/white one up high near hood latch lets air in as per design.

I did check spark one day at lake when it was hotter than hell out. All was good on both cylinders. I will recheck. I will swap a CDI also, then if that doesn't help hot start I will swap ign. coil. One thing at a time so I know what fixes it.

If this ski has had the same hot start issue with different engines then I would look at the fuel system and tank as well as the electrical parts in the box.
We used to have Kawasaki 550,s back in the day that world run fine cold but after the CDI boxes would run for a while and get warm then run bad and not restart until they cooled. Faulty electrical parts get worse with heat when the resistance goes up.

 

[mikidymac]

I have seen stators crap out when hot too.

 

[1983]

Ive seen them do weird stuff too when hot.

This is a whole different engine and stator, so I am thinking it is something that is a constant in the hull that feeds each engine. Each engine has seen the same fuel tank/vent system, the same coil, and the same front ebox.

Wonder what the heck is going on, it runs so good on the top end which makes me think it isn't the coil or CDI but its worth a shot.

Its just so weird that I can hold it WOT at crank after its been sitting and it won't attempt to fire, but if I choke it it will fire off then die. Im adding more fuel when choking?! its already got enough lol

I have seen stators crap out when hot too.

 

[manolocross]

Crap I had the same problem with my SPX this weekend. Hot restart problem.
Subbed so I can see the outcome.

 

[1983]

Was it real hard to clear out like the engine had way too much fuel in it from when it was sitting?

Did you happen to pull spark plugs to view if they were wet?

I hope we can all resolve our problems.

Crap I had the same problem with my SPX this weekend. Hot restart problem.
Subbed so I can see the outcome.

 

[benjilafouine]

Well, I would think your RV and cover have nothing to do with this issue then. I ran my ski last year for 10 hours with a badly aligned RV and the issue was constant, hot or cold. Ski was always hard to start, cold or hot and acceleration would be erratic all the time.

But since you had two engines and new carbs with same issue, this is a bit puzzling.

What happens if you add starting fluid directly in the cylinders when it is hot and won't start?

Benji.

 

[mikidymac]

Don't use starting fluid on a 2-stroke. Washes away any lubrication.

 

[benjilafouine]

Actually, I made my own fluid: last year, I used premix gas that I fed down the cylinders when my ski was wrecked (used the chain saw gas). I may not be much of a mechanics but I am wise enough to know that! Anyway, I doubt that one ounce of gas would kill a whole engine in a split second unless you keep doing that for one hour. But better be on the safe side.

Note: did that with ski-doos all my life when they would not start in 10 below cold...

Benji.

 

[1983]

Well I've found what's happening but don't really understand how diaphragms are pushing on lever....

Video is uploading to YouTube now, slowly

I put RV cover and carbs back on.

Hooked ski up to garden hose and started it, then turned on water. I let it run for about a minute. Turned water off and then turned ski off inspected carbs, started it back up and let it run on hose for a bit longer ( no I don't have a carbon seal ) turned engine off and watched the carb throats with flashlight and mirror. PTO carb isn't dripping but I see some fuel covering throat.

Now for the MAG carb its dripping fuel into crankcase causing over rich issue only when warm. So even if your carbs pass the bleed down psi test on the bench with wd40 in the real environment of hot engine and fuel in carbs they can still leak.

Seat was off, storage bin out, hood propped open, and fuel tank ventilation system is working as designed, plus late in day with no sunlight so fuel tank was definitely not pressurized. Let's rule that out.

Has to be diaphragms holding needle open. Guess an adjustment way below carb metering chamber floor is in order. Which will raise pop off significantly. Will tinker tomorrow evening.

Video coming soon if it will ever upload. I wonder if the kits I've been buying truly are OEM Mikuni....

Rob

 

[manolocross]

My issue with a hot restart happened the other day. 90 degree heat and 3/4 tank burned and idled through no wake zone 10 min. Tied up to dock. Removed ski from water 20 min later and would not start. Never did that before. Hmmmm

 

[1of500]

Well I've found what's happening but don't really understand how diaphragms are pushing on lever....

Video is uploading to YouTube now, slowly

I put RV cover and carbs back on.

Hooked ski up to garden hose and started it, then turned on water. I let it run for about a minute. Turned water off and then turned ski off inspected carbs, started it back up and let it run on hose for a bit longer ( no I don't have a carbon seal ) turned engine off and watched the carb throats with flashlight and mirror. PTO carb isn't dripping but I see some fuel covering throat.

Now for the MAG carb its dripping fuel into crankcase causing over rich issue only when warm. So even if your carbs pass the bleed down psi test on the bench with wd40 in the real environment of hot engine and fuel in carbs they can still leak.

Seat was off, storage bin out, hood propped open, and fuel tank ventilation system is working as designed, plus late in day with no sunlight so fuel tank was definitely not pressurized. Let's rule that out.

Has to be diaphragms holding needle open. Guess an adjustment way below carb metering chamber floor is in order. Which will raise pop off significantly. Will tinker tomorrow evening.

Video coming soon if it will ever upload. I wonder if the kits I've been buying truly are OEM Mikuni....

Rob

Are they in the sealed mikuni pack or are the loose. I bought some last year that were supposed to be genuine but came in a bag. The nipple on the diaphragms were the reddish pink color but I could tell a difference in the other parts. I left the guy a bad review he blocked me ill try to find the add

 

[mikidymac]

If you are doing the leakdown test with the carbs completely together with diaphragms and covers on they shouldn't leak when put on the ski. The thing that confused me was the WD-40 because you don't need it when they are sealed back up for the final leakdown.

I had one do this to me that checked out perfect and then dribbled using all genuine Mikuni parts. When I took it back apart there was a little piece that looked like a toothbrush bristle holding the needle open. To this day I have no clue where it came from as I have never seen anything like that in my garage, maybe from the filter at the factory.

 

[1983]

Yup i'm doing the leak down and pop off test both with carb fully assembled to simulate what it will be like when installed. It holds 20 psi for 10 mins without gauge needle moving. Spec is much lower psi for test so I would have though 20 psi would be a sure thing that these won't leak when engine is off or idleing. Levers are set at metering chamber floor height with razor blade as per manual says page: 06-03-5

http://******************/download/pdf/service/manuals/1996/1996-seadoo-service-shop-manual.pdf

I can't believe there aren't more people with hard warm starting and idle loading up issues. ( there are quite a few lol ) I just used the WD40 to lubricate needle and seat as some form of liquid.

That is odd, wonder where that bristle came from.


Rob

If you are doing the leakdown test with the carbs completely together with diaphragms and covers on they shouldn't leak when put on the ski. The thing that confused me was the WD-40 because you don't need it when they are sealed back up for the final leakdown.

I had one do this to me that checked out perfect and then dribbled using all genuine Mikuni parts. When I took it back apart there was a little piece that looked like a toothbrush bristle holding the needle open. To this day I have no clue where it came from as I have never seen anything like that in my garage, maybe from the filter at the factory.