Help- no start, take plug out fires up, put in runs fine, shut off- again no start

[easygoin4]

I’m not too familiar how seadoo work, valves and everything
But will crank and crank, take out one plug to check spark, fires right up. Put plug back in starts fine and runs.
Shut engine off, no won’t start unless pull plug again.
1997 challenger boat single 787
OEM carb rebuild, new rings, seals and gaskets.
New fuel
Took engine apart early last yr for rave valve.
Ran it last year 2 times
This year not in water yet, however it did run in driveway with water, now this
Any idea
Thanks in advance

 

[POPPS]

On that motor both plugs fire at the same time, ,,one piston is at tdc, and one piston is at bdc....its possible that your battery is weak,,,so that by removing a plug,,,the starter doesn't have as much compression to crank against. With the battery at 12.6 V at least, do a load test.

 

[easygoin4]

Battery wan new early last year I always put it in 2amp charge before I try it. She cranks well with plugs in.
However always noticed that when I hit start button it’s not instant crank takes about 2-3 seconds before cranks, but it cranks fine.
I’m baffled how it will start if I take plug out first, then put back in she starts, but shut it off and won’t start again
Thanks again for responding
Be safe

 

[easygoin4]

Found that my plugs are soaked all the time. Take out and crank, put my hand over and gas all over my hand, seems like way too much. Assume plugs won’t fire all wet, put new ones in fires up, shut off won’t go
Any ideas as to too much fuel?
Thanks

 

[easygoin4]

I have video of running but can’t post. Shut it down and then no start.

 

[etemplet]

I was going to suggest that you have a seal leaking internally allowing oil to get into the combustion chamber. That scenario is typical of an oil soaked engine. Generally though after you get the engine running a bit it fires up pretty well till the engine sits and gets oil soaked again. It happens quicker in some engines than others. I installed a valve in my wife's ski. Her's takes about 2 weeks of sitting before starting becomes an issue but after I pull the plugs and get the oil out.. it fires right up every time and runs great.

I did have a 787 RFI that left an injector energized. It filled the engine with fuel very quickly. The issues was the MPEM. Good Luck !!

 

[etemplet]

Found that my plugs are soaked all the time. Take out and crank, put my hand over and gas all over my hand, seems like way too much. Assume plugs won’t fire all wet, put new ones in fires up, shut off won’t go
Any ideas as to too much fuel?
Thanks

Is it fuel, oil, or water?? Do a compression check. As suggested you may have a bad starter or wiring. Even a battery that checks good can still be bad. Good Luck

 

[easygoin4]

compression 150/149, brand new plugs - looks like fuel with oil, smells like gas.
Wondering if I need to pull carbs and check rotary valve cover clearance?
Thank Again....

 

[etemplet]

If it is fuel you need to check your Pop-Off and needles for leaking. Not sure if that little check valve under the block could cause that sort of problem. Perhaps you have a problem with the rotary valve clearance but you have a strange problem.

 

[easygoin4]

Thanks for looking..
I was told the guys that did my carbs, checked the needles/seats and held pressure, they adjusted my pop off to 33 psi each.
I will pull carbs again and measure valve cover clearance.
I'm kinda hoping its WAY out of spec- just to get this thing fixed..
Been promising the wife all year I would take her out on the boat..

Thanks again...

 

[etemplet]

Well the main thing is... don't give up. This equipment keeps finding new ways to confound owners and mechanics. Verify it isn't water and fuel mixed. The choke can put a lot of fuel into the cylinders if it is not operating correctly or set properly, enough to flood the system. Check your flame arrestor for plugging. Any air restriction will pull fuel into the engine. Just some thoughts.

 

[easygoin4]

I cant give up- Got this from original owner and its now so clean, redid seats myself. Nice little boat for us old folks to get around in.
You would be amazed how clean it is now, from bilge to bow.
I have used the choke every time i try, and I'm outside in the hot sun in driveway, maybe I should ease up on it some. Air cleaner box is clean also...
I will figure it out- I hope soon..
Thanks Again...

 

[POPPS]

Rotary valve clearance usually is an issue on a hot motor that has been running, the clearance increases and makes starting very difficult.

 

[easygoin4]

Took off carbs and inspected valve clearance as per the manual, remove cover, remove o-ring, re-torque and measure.
I cant quite get a .014 feeler in there, but a .012 will fit.
As per the manual its in great shape..
Now- I assume to go back to needles/seats, even tho they were tested good to hold by the guy who rebuilt my carbs.
Thanks all for looking and helping..

 

[POPPS]

Don't assume the truth from the seller, leave no stone unturned when it comes to watercraft.,,there are always surprises.

 

[Countryboy88220]

If its anything like mine don't use the choke every time you try to start it. You will flood it out and thats probably why it starts when you pull the plug out. The manual says to just give it a little bit of throttle to start it after it has warmed up.

 

[easygoin4]

Well got carbs back with new needles/ seats all installed Wont Start
Plugs soaked every time.
I’m going to try low speed setting to 1 turn out as manual says, carb guy has set to 1 3/4 out.
Maybe this is it.
So frustrating, I’ve posted on FB site to see if anyone in SE Michigan area to help me.
Promise the wife this year yet a boat ride.
Running out of options
Thanks

 

[easygoin4]

Here is typical 5-10 seconds of cranking clean white rag.
Any ideas
Thanks

 

[mikidymac]

Did you test pop-off and leak down on the carbs?

 

[easygoin4]

yes carbs redone by a guy who has been doing this stuff for years, and set pop off to 35psi, tested all circuits of carbs.
Thanks

 

[mikidymac]

Well your needles are leaking and flooding the engine if the plugs are that wet and spitting that much fuel out in just 5-10 seconds.

Tell him to check the carbs for leak down.