SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: tahiti mike on August 01, 2010, 09:49:00 AM
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ok here is the problem at hand. 454 tunnel dual holleys .runs fine then when you get in the throttle is gose for about 5 five min or so and starts to loose power.let out of the throttle and cruise then get back in it same thing five min or less and starts slowind down . any suggestions. ive checked fuel pressure and volume. timming :banghead:
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Sure sounds like your running the bowls dry the carbs. What kind of rpms are you turning with your foot in it? How big are the carbs? What kind of fuel pump? What size lines? Where did you check pressure? Are you running a regulator? If so, what kind?
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dual 650 holleys 3/8 fuel line 4200 rph holley manual fule pump with a electric fuel pump asist ive checked at the carbs running a holley regulator ive even uped the pressure to 8 lbs instead of the 6 i was running before .
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check your fuel for water.. My boat did the same thing last trip and it ended up being water in the fuel.
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done that been fightin this problem since i swaped from a panther pump to this stupid berkley cause i coudnt get my rpms down now there down and it has this gremlin
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done that been fightin this problem since i swaped from a panther pump to this stupid berkley cause i coudnt get my rpms down now there down and it has this gremlin
that is the first time iv'e heard berkeley and panther in the same sentence and call the berkeley stupid.....
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Since the berk pulled your rpms down. It's putting a greater load on the engine. Greater load means more fuel. Your sucking the bowls dry. When you get out of it fuel demand drops and the bowl level recovers.
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Since the berk pulled your rpms down. It's putting a greater load on the engine. Greater load means more fuel. Your sucking the bowls dry. When you get out of it fuel demand drops and the bowl level recovers.
I think he's rite. My duel 660s did that a while back. Youl have to watch the pressure when you on the peddle, not too easy depending on where your gauge is, also it still may show pressuse even if the bowls are empty. Help me out on this one guys. I dont know crap about carbs, lol just 2 stroke dirtbike "dinorsor" carbs ;)
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it goes sound like you are running out of fuel do you have the clear sight glass on the side of the bowls to have someone check it out. ibhsbz i'm with you dry bowls
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Bring the fuel level up in the bowls
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Run larger fuel line. Do you have a fuel water seperator or a fuel filter? If so they could be clogged.
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How are the fuel tank vents. These boats have vents built into the flip up fill caps but I do not trust them. When this "low power" is happening flip the fuel fills up and see if it goes away. I have also seen the very small factory fuel pickups cause a lot of fuel problems as well.
T.J.
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Chased a similar problem around on Pickle. IN the end, Rivertard was kinda right. He said he heard a distinct vacuum leak while in the boat at full throttle. Later, we tried timing, noone else heard the leak............Musta been the 'cow whisperer' in Mike that was the only one to hear it.......... :screwy:
In the end was a combination of problems. First, yeah, serious vacuum leak in the vac secondary bladder housing, as well as the bladder itself pretty much trash. (Explains why it would run balls out after idling a few minutes, but lift? ran like crap and would stall, spit and sputter, etc) That's one.
Second was the vacuum advance on the HEI. I hate HEI BTW on these boats, but it came with it, ran good for soooo long, but, after the carb problems were found, and fixed (By a fresh 850), had issues with the spitting and sputtering again at speed. DONE with the HEI. Put in a Unilte, which I know some hate and I love, been good in the driveway! we'll see what it does on the water! :thumbup:
Ray
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How many rpms were you turning with the panther? What impeller did you go with in the berkley?
What speed were you seeing with the panther vs. now with the berkley?
Just curious.
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rev set at six and it would stay on the rev would spin higher. went to an a/b stanless 63 mph at six .now 4200 and 55 mph.
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How many rpms were you turning with the panther? What impeller did you go with in the berkley?
What speed were you seeing with the panther vs. now with the berkley?
Just curious.
Can spin at 4300 with a bronze AA in my Berk pretty easy. Haven't had the boat wet since the carb/ignition change to know if I got more. Probably will, spun 5200 +/- last year, that was also with an old tach that broke, so take that for what it's worth.
Personally, I think the motor needs more to waken up the pump. Haven't GPS'd Pickle, but it was a 60ish boat last year, 50ish this year. Hopefully fixed all that, another wet test, maybe Sunday, then it's for sale!
Ray
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I'm going with TJS on this one, sucking the fuel tank into a negative and impeding dinosaur pee flow... ;)
GT
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problem solved.need a new engine block lifter bores are oblonged and are causing them to bind up. any one have a 454 sixty over?