Carbs spitting fuel

[DMAL]

I have a 97 SeaDoo Explorer with a 717 engine. It starts fine and runs ok until it gets warmed up. After about 1/4 mile of riding it will start to bog down and will not maintain plain on the water. I can tickle the throttle and and get it to take off again, but it will continue to bog down every time. I took it for a ride with out the seat and air box so could watch it. When it's bogging down it spits fuel mostly from the Mag carb.

What can cause a carb to spit fuel?

Is there a valid way to check the crank case for air leaks on an installed engine? I have started to block off the intake and exhaust...I used rubber roofing in the place of the gaskets. I connected the gauge and pump to the pulse fitting. My gauge was not accurate enough at low pressures so I will try again with a better gauge tomorrow. I am not sure what the pressure was, but I did see air bubbling up in the oil return line.

Do I need to pinch off the oil lines?
Is there a pressure spec on the crank seals?
Is my test even a valid test?

 

[DMAL]

Update

I have checked a couple of things that may be clues. I swapped the needle, seats and springs in the carbs to see if I could move the spitting to the PTO carb. It was still spitting from the Mag carb when it bogged down, but if I choked the PTO carb with my hand for a second or so it would take off and run fine.

Also in my process I discovered that the the rotary valve cover has some scratches, one scratch is just big enough to catch my fingernail on and there is a gouge from a small screw or bolt. I am not sure how significant this is.

So It looks to be a fuel delivery problem, but I am not sure if it is one or both carbs...or if it could be the rotary valve cover.

 

[Scott06]

If the carbs are overflowing fuel it is either from a needle and seat/ float issue or too much fuel pressure . I would get the carbs rebuilt and makes sure the fuel supply is clean of water and debris before tackling other issues liek the rotary valve. May be an issue there but would probably not keep it from running

 

[DMAL]

If the carbs are overflowing fuel it is either from a needle and seat/ float issue or too much fuel pressure . I would get the carbs rebuilt and makes sure the fuel supply is clean of water and debris before tackling other issues liek the rotary valve. May be an issue there but would probably not keep it from running

Only one carb is over flowing fuel. The other carb requires choking or spraying fuel to get it to take off and go. Which carb is the suspect, the one spitting or the one that needs to be choked.

 

[DMAL]

I have carb kits and I am waiting for new needle and seats. I plan on checking all factory settings.

 

[Scott06]

Only one carb is over flowing fuel. The other carb requires choking or spraying fuel to get it to take off and go. Which carb is the suspect, the one spitting or the one that needs to be choked.

Both are in need of rebuild. The one overflowing has a float and/or needle and seat issue. the one you need to choke has plugged fuel passages. Would not use it if you need to choke one to run as that cylinder will be lean and likely detonating which can fry the piston

 

[DMAL]

Both are in need of rebuild. The one overflowing has a float and/or needle and seat issue. the one you need to choke has plugged fuel passages. Would not use it if you need to choke one to run as that cylinder will be lean and likely detonating which can fry the piston

I have only taken it out on the water it for diagnostic purposes. I put a used engine in it 3 years ago and was never able to get it running right, so It has been setting until now. I rebuilt the carbs with the engine install, but I am just beginning to have some understanding of these carbs, so I expect to find something that I did wrong.

While waiting for parts I have checked the pop off One carb pops off clean at 40 PSI and reseals with no leaks. The other carb starts to leak at 40 PSI and pops off at 43 PSI and leaks before it reseals.

 

[QBhoy]

Compression test ok ?

 

[DMAL]

I finally got around to rebuilding the carbs. It still spit some fuel from the mag carb. Others have said that some spitting is normal. I don't know if that is true or not. It is running much better now...there is still a little hesitation during acceleration. I am not too clear on how to tell the difference between a lean hesitation or a rich bog. I have also may need a wear ring...maybe that can cause the acceleration issue that I am seeing.

Any thoughts?

The compression was ok when I put it in I need to recheck it after my carb tuning attempts. Carbs are set at factory settings now.