1983
Well-Known Member
Whats up guys?
I'm almost at the point of buying carbs or sinking this thing lol.
Conditons: loading up at idle, will not hot start.
Subject: RV clearance, RV cover avail, carb settings.
Ski: 1996' XP stock 787, stock airbox and flame arrestor.
Settings: 1.5 needles and seats, 35 or 39 psi pop offs, 1 turn out low speed needles, closed high speed needles. 150/155 compression. Carbs hold bleed down test and pass each time, 20 psi held for 1 min. Fuel system is completely fresh, tank was yanked and cleaned last month, new fuel lines of course and all those bases covered.
I am fighting a really bad hot start condition on one of my seadoo 96' XP. Everything is set to spec, tried 2 different sets of carbs, both rebuilt with full OEM mikuni kit with 1.5 new mikuni needles and seats. I've tried pop off at 35 psi in each carb, and raised pop off too right at 39-40 psi. Spec is 23-43 psi. Ive tried adjusting lever arm 1mm below carb body and that didn't help at all. I was thinking the diaphragm red nipple was pushing on lever and keeping needles open and fuel was being pushed into carbs when engine is off. Didn't help. Ive checked multiple times with engine running at idle with a mirror and flashlight and no fuel is dribbling into carb throat. Why does it load up at idle in no wake? I've had low speed needle at 1 turn out, 3/4 turn out, and 1/2 turn out just to see what would happen and none helped. ( I know messing with the low speed needle is a band-aid and isn't proper but I wanted to see what would happen )
Mikuni manual says to raise pop off if you have a condition where ski loads up while idling through no wake zones. Mine does this also, if I idle for more than 6-10 seconds and try and give it gas it bogs falls on its face and dies. Hard to restart. I have to choke it? isn't that odd?
If I hold throttle wide open and crank it it won't start when hot not even hit after cranking for 20-25 seconds, either after sitting at dock for 10 mins, or out of the no wake idle zone as mentioned above when it dies. Now if I choke it and hold throttle open it fires off and tries to clear itself out if I keep throttle nearly WOT. But 80% of time it just won't restart. Even with new set of gapped plugs it wouldn't restart while sitting at dock for 10 mins. Seems overly rich when its hot and been sitting...but then I am thinking everytime I choke it while trying to restart it is producing the overly rich condition....
Brings me to my question could this be rotary valve clearance? I am going to measure clearance tonight. All I can think of is clearance is too great and this is causing hard hot starts. I have gone through fuel system completely of course and all is new and fresh, fuel feed is direct from reserve nipple on fuel tank to an inline filter to MAG carb inlet. No fuel water separator, no fuel on/off selector. Just direct from reserve nipple to carb.
Fuel tank vent system is working correctly with the check valves, and when I take gas cap off on a hot day there is no pressure sounds like tank is under PSI. Ski is premix 40:1 if that matters. It is getting spark when hot also, I think i've covered all my bases haha.
Thanks all,
Rob
I'm almost at the point of buying carbs or sinking this thing lol.
Conditons: loading up at idle, will not hot start.
Subject: RV clearance, RV cover avail, carb settings.
Ski: 1996' XP stock 787, stock airbox and flame arrestor.
Settings: 1.5 needles and seats, 35 or 39 psi pop offs, 1 turn out low speed needles, closed high speed needles. 150/155 compression. Carbs hold bleed down test and pass each time, 20 psi held for 1 min. Fuel system is completely fresh, tank was yanked and cleaned last month, new fuel lines of course and all those bases covered.
I am fighting a really bad hot start condition on one of my seadoo 96' XP. Everything is set to spec, tried 2 different sets of carbs, both rebuilt with full OEM mikuni kit with 1.5 new mikuni needles and seats. I've tried pop off at 35 psi in each carb, and raised pop off too right at 39-40 psi. Spec is 23-43 psi. Ive tried adjusting lever arm 1mm below carb body and that didn't help at all. I was thinking the diaphragm red nipple was pushing on lever and keeping needles open and fuel was being pushed into carbs when engine is off. Didn't help. Ive checked multiple times with engine running at idle with a mirror and flashlight and no fuel is dribbling into carb throat. Why does it load up at idle in no wake? I've had low speed needle at 1 turn out, 3/4 turn out, and 1/2 turn out just to see what would happen and none helped. ( I know messing with the low speed needle is a band-aid and isn't proper but I wanted to see what would happen )
Mikuni manual says to raise pop off if you have a condition where ski loads up while idling through no wake zones. Mine does this also, if I idle for more than 6-10 seconds and try and give it gas it bogs falls on its face and dies. Hard to restart. I have to choke it? isn't that odd?
If I hold throttle wide open and crank it it won't start when hot not even hit after cranking for 20-25 seconds, either after sitting at dock for 10 mins, or out of the no wake idle zone as mentioned above when it dies. Now if I choke it and hold throttle open it fires off and tries to clear itself out if I keep throttle nearly WOT. But 80% of time it just won't restart. Even with new set of gapped plugs it wouldn't restart while sitting at dock for 10 mins. Seems overly rich when its hot and been sitting...but then I am thinking everytime I choke it while trying to restart it is producing the overly rich condition....
Brings me to my question could this be rotary valve clearance? I am going to measure clearance tonight. All I can think of is clearance is too great and this is causing hard hot starts. I have gone through fuel system completely of course and all is new and fresh, fuel feed is direct from reserve nipple on fuel tank to an inline filter to MAG carb inlet. No fuel water separator, no fuel on/off selector. Just direct from reserve nipple to carb.
Fuel tank vent system is working correctly with the check valves, and when I take gas cap off on a hot day there is no pressure sounds like tank is under PSI. Ski is premix 40:1 if that matters. It is getting spark when hot also, I think i've covered all my bases haha.
Thanks all,
Rob
