SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: ONE-A-DAY on May 18, 2014, 08:20:22 AM
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Got up early to hit the lake before the crowds. Place was empty, perfect.
Boat ran great if I kept it mid throttle and just cruised around. When I opened it up it would run like a raped ape for 5-10 seconds and then die.
It wouldn't restart right away, battery would barely crank it over. Waited about 5 Minutes and then it would fire up and run again just fine if I just drove around, as soon as I hammered it, it would die again after about 5 seconds of full throttle.
I put a brand new battery in it last night. I checked voltage when I got home and it was 12.5.
Any suggestions?
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That sounds like too much trouble. Give it to me and I'll get it sorted out for you and return it when I'm done with it next season.
Now if you really want to spend the time yourself I'd suggest double checking fuel pressures & flow (change fuel filters), Inspect fuel hoses for cracking or sucking air, debris in the fuel tanks, check the needle and seats and float levels also.
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Sounds to me like it's possibly starving itself for fuel after you hammer it
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That sounds like too much trouble. Give it to me and I'll get it sorted out for you and return it when I'm done with it next season.
Now if you really want to spend the time yourself I'd suggest double checking fuel pressures & flow (change fuel filters), Inspect fuel hoses for cracking or sucking air, debris in the fuel tanks, check the needle and seats and float levels also.
Pretty sure it's the carbs that are full of crap from sitting so much. The hard cranking makes me think the ignition timing is off as well.
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It would run all day on the primaries, as soon as I hit it and the secondaries kicked in it was done
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Also make sure the fuel tank vents are working
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Recently done any changes?
Sent with my Fingers
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Recently done any changes?
Sent with my Fingers
Just bought it, so no changes, prior owner hasn't used it much at all for years
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Just curious... what was the oil pressure like?
I see two problems that may or may not be related... one... as soon as you get into the secondaries, it shuts down... possible fuel issue or ignition issue. Then it cranks slowly and won't start until it sits... which seems electrical in nature. I'd check your fuel pressure... check fuel lines, vents, etc... just for nothing more than it has sat and you don't know the condition of the system until you check it out. Second... I'd take a peek at your ignition timing and see where it is at intial... which may be part of the slow cranking if it is way too high. Also... another place to look is your coil and/or ignition module/points/ballast resistor if your distributor has any of these... an electrical ignition part can really cause a great deal of headache when they work fine under a light load... and then start causing problems under heavy load/demand. I'd be willing to bet that you're gonna find that one of these will be your issue... BUT...
the reason I asked about oil pressure is that there is the waaaaaaay off chance that you may have a mechanical issue... seen it several times, most of the time they were Olds 455's... but you'd see for sure signs of a mechanical issue... low oil pressure... knocking... etc... Only mention it because... if nothing else is the problem, then you're left with one.
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Carb and fuel system need to be checked im running two fuel filters. One of which is a water seperator
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Just curious... what was the oil pressure like?
I see two problems that may or may not be related... one... as soon as you get into the secondaries, it shuts down... possible fuel issue or ignition issue. Then it cranks slowly and won't start until it sits... which seems electrical in nature. I'd check your fuel pressure... check fuel lines, vents, etc... just for nothing more than it has sat and you don't know the condition of the system until you check it out. Second... I'd take a peek at your ignition timing and see where it is at intial... which may be part of the slow cranking if it is way too high. Also... another place to look is your coil and/or ignition module/points/ballast resistor if your distributor has any of these... an electrical ignition part can really cause a great deal of headache when they work fine under a light load... and then start causing problems under heavy load/demand. I'd be willing to bet that you're gonna find that one of these will be your issue... BUT...
the reason I asked about oil pressure is that there is the waaaaaaay off chance that you may have a mechanical issue... seen it several times, most of the time they were Olds 455's... but you'd see for sure signs of a mechanical issue... low oil pressure... knocking... etc... Only mention it because... if nothing else is the problem, then you're left with one.
Oil pressure is fine, fuel pressure was low though. Gonna change filter and separator and pull carbs apart, and check the timing.
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I had same problem turned out I had to have carb rebuilt. Secondaries were running out of fuel. Changed carb runs good
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The hard starting is a clue...a big one. Does it crank faster after it sits for a few minutes? When it does...does it just shut down like you turned the key off or just lose power and finally quit. I'm suspecting something might be binding up as soon as you start creating some good heat. My 2 stroke jet ski did the same thing when piston to cylinder clearance was right...piston would get hot, expand and stop the motor in it's tracks....wouldn't crank right away. After 20 seconds, it would crank slow. after a minute, it would lite right up and run great till I got it hot again. Do you have an oil temp gauge?
I'd go test it again and bring a ratchet and socket for the crank bolt with you....duplicate the problem and immediately after it quits, unplug the coil and try to crank it (timing error)...if still tough to crank, try to turn the engine by hand with the crank bolt. You need to determine whether you have a binding issue or whether you have a starter issue. I might also consider disconnecting the pump, pulling the bowl and seeing how that thrust bearing feels. also, make sure the impeller isn't running into the wear right or suction housing.
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The hard starting is a clue...a big one. Does it crank faster after it sits for a few minutes? When it does...does it just shut down like you turned the key off or just lose power and finally quit. I'm suspecting something might be binding up as soon as you start creating some good heat. My 2 stroke jet ski did the same thing when piston to cylinder clearance was right...piston would get hot, expand and stop the motor in it's tracks....wouldn't crank right away. After 20 seconds, it would crank slow. after a minute, it would lite right up and run great till I got it hot again. Do you have an oil temp gauge?
I'd go test it again and bring a ratchet and socket for the crank bolt with you....duplicate the problem and immediately after it quits, unplug the coil and try to crank it (timing error)...if still tough to crank, try to turn the engine by hand with the crank bolt. You need to determine whether you have a binding issue or whether you have a starter issue. I might also consider disconnecting the pump, pulling the bowl and seeing how that thrust bearing feels. also, make sure the impeller isn't running into the wear right or suction housing.
Pat always has the answer. I hate you pianee man lol...i love you bro give me a call sometime. Tell mama and the boy I said what's up.