From joy to dispair in less than 45 mins!!!

[UrbanLegend49]

Man, took the boat out today for my first run with her and she went into the water easy as pie, fired right up, hit the open water and felt great. The only little complaint would be some rattling, mostly from looserails.

Took her accross the lake, opened her up about 3/4 of the throttle and she was flying and riding nice. She was much faster than I thought and she was bouncing up and down nicely on the waves.

I brought her into the dock just to check things out and everything seemed fine, so I took her out again and I heard a ticking sound (not knocking) and it seemed to be coming from the right side header, as I went on, the ticking sound got increasingly worse, (I know it was an air leak of somekind) and about the 4th pass accross the lake she started losing power.

I just cruised her along the shoreline a few mins, and when I put the throttle down to go again, almost nothing, there was hardly any power in the throttle. I pushed the throttle down (now the ticking sound coming from the header is as bad as it had gotten) and when I pushed it forward *POP*, BANG *POP* and smoke from the carburator.

I then just cruised her very slowly back to the dock and pulled her out of the lake.

When I got home, she fired right up and sounds okay, but there's no doubt that there's somekind of header leak, and then there's something going on with the carb.

I was thinking maybe some old gas, or possibly some water in the gas or something, but to go from running so good, to no power at all the quickly something's wrong.

Where do I start???

[Hottrucks]

since it has header it must be a car motor??? if we knew more it would be better...

but it sounds like a soft lifter if there hydralic or a rocker coming off or bent push rod???
I hope I'm wrong................

[UrbanLegend49]

Sorry, yes it's a 460.

Could running it on a hose and running it at the lake make the motor act different?

[Hottrucks]

Yes....how was the water temp????? maybe a bad water pump.........the hose will force water through and that doesn't happen at the lake. There maybe enough to keep it cool idleing but not at WOT

[Wile E. Coyote]

if you bust a rocker, stud, or something in the exhaust side of the valve trane, it will exhuast thru the carb, and if its a holley carb, the first time it does that, kiss the power valve in the carb goodbye as well, first things first, pull compression, then leakdown, find out what is going on....make sure the motors not hurt.....good luck

[Scott in MN]

Check the timing.....If it's not a timing issue I'm guessing valvetrain. I had a big block pop back thru the carb after the big solid lifter cam broke the rocker arm off.

[afr]

sounds like a cracked valve or head or maybe even a head gasket
not good
better do what coyote said asap could have water on top the piston aswell now

[pancho]

The fact it may only only do it under a load speaks volumes do what the others have said and eliminate possibles

[Raceman]

First thing: compression test on all 8 cyls.

[Ripper]

Good luck, let us know what you find...

Rip

[Riverratt]

since it has header it must be a car motor???

Since it is posted in the jet and V drive section that would be a good guess.
Jet Boats and V-Drives Inboard V8 power - This is the place for jet boat and V-drive discussion

[Hydrophobic guy]

Well,
My car boat motor threw two lifters out on two holes and tried to suck an intake valve through on another hole. Still brought us home on 5 thou. Compression test told me the story then proper disection told me the rest. Luckily the bottom end didn't get hurt. Had a fellow S&F'er do my heads and she was out this weekend back to runnin like the hammers of hell with the rest of the nuts. Oh, and ole Hottrucks was boatless BWAHAHA better get that Action runnin Jeffy.

[pancho]

Good news on the motor gotta love those not prone to melt down engines nice to have have some iron around your hot stuff.

[VAMI]

get the valve covers off and check the rockers sounds like one broke

[jrork]

get the valve covers off and check the rockers sounds like one broke

Ditto, pull the covers and after you have checked for obvious things like broken rockers, springs, etc... Have somebody turn over the motor (without starting it) and look everything over. I lost a lobe once and had a very similar issue. Pulled the valve cover and you could see the rocker off that lobe just wiggle instead of going through the cycle.

Good luck and welcome to boating. This is just part of it and we've all been there (more than once).......john