SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: americanbull on June 14, 2009, 08:14:04 PM

Title: leaking at WOT?
Post by: americanbull on June 14, 2009, 08:14:04 PM: ok, have a 454 with a berkeley jg pump. new packing gland and transom sealed. at idle there are no leaks from pump or cooling lines. have a valve at inlet line and outlet, both are fully opened. problem at idle the motor heats up to redline but once going its fine. is this because there's not enough water circulating? and then when the water can get through the headers it flows more? other problem is when not at idle (usually above 3000 rpm) there is a leak coming from somewhere. and its a pretty good one. my guess was a hose or something leaking when theres more pressure but I can't find anything wrong. any help....its driving me crazy. nothing like letting off the throttle and have a river come down the center of the boat. thanks for anything ya got
Title: Re: leaking at WOT?
Post by: Nordie on June 14, 2009, 08:18:41 PM: Possible freeze plug?
Title: Re: leaking at WOT?
Post by: IRRebel on June 14, 2009, 08:35:28 PM: Obviosly you're running OT headers. How is the thing plumbed (Pics please, I went through every thread on this site when I did it, and still started a new one, easy to mess it up) and is this a new problem on a proven boat or a new (or rebuilt) boat that has this problem?

Ray
Title: Re: leaking at WOT?
Post by: ROMPERSTOMPER on June 14, 2009, 08:35:55 PM: What size hoses are connected to your motor from your pump. You may not have enough valume of water to your motor due to small water lines, like -6, -8, at low rpm. also check your thermestat. sp, if you have one. Is there a bypass relief valve in your cooling system. jet pump at high rpms put out tons of water pressure. If you using old style hoses like heater hose, there not rated for high pressure and or have a cracked hose on that only leaks when the pressure builds up.
Title: Re: leaking at WOT?
Post by: americanbull on June 14, 2009, 08:37:35 PM: has had this problem since i got it. i don't have any pics but theres just one line in and one line out. all of the plumbing looks to be original
Title: Re: leaking at WOT?
Post by: americanbull on June 14, 2009, 08:39:36 PM: not sure of line size but they're pretty big. inlet line is just a rubber hose and outlet is braided s/s
Title: Re: leaking at WOT?
Post by: IRRebel on June 15, 2009, 03:35:34 PM: You've got me. Tom???? :sly:

BTW, hows the oil, milky at all?

Ray
Title: Re: leaking at WOT?
Post by: americanbull on June 15, 2009, 05:46:57 PM: oil is clean, no water present. it doesn't make sense to me how that much water can get in the boat without a leak at idle.
Title: Re: leaking at WOT?
Post by: GT Jets on June 15, 2009, 05:51:09 PM: Your avatar pic could explain a lot??? Are you sure the water is coming from the engine?

Line sizes are the last place I would look, I'm thinking you have a pump issue. Is the bowl gasket inside the boat? :sly:

Pics are worth 1000 words... :thumbup:

GT
Title: Re: leaking at WOT?
Post by: americanbull on June 16, 2009, 05:40:18 PM: yeah bowl gasket is inside the boat....haven't thought of that one! and i'm sure the leak is coming from the engine/pump. i've gotten pretty good at fiberglass work haha. i'll try to get some pics next time i see the boat.
Title: Re: leaking at WOT?
Post by: Marcsrollin on June 16, 2009, 10:27:36 PM: Check the hand hole cover o-ring! My old tahiti did the exact same thing and that is what it ended up beeing!
Title: Re: leaking at WOT?
Post by: americanbull on June 17, 2009, 05:31:18 PM: cool i'll check that this weekend. i just had the handhole off and didn't think to check the oring too...