Carburetor, sounds a lot like a lean pop..

Floats too low?

How much fuel pressure?

Restricted pick up?

What do you have for ignition? Electronic?

Exactly where I'd be looking. More leaning towards the "lean" condition, extremely lean, to be honest.

Ray



Could also be something more serious like a valve hanging up, but sort of wanted to start simple and cheap first.

I've seen that on every 460 I've ever torn down, and honestly, I think it's just a cheap FoMoCo spacer (thick gasket really) to get the carb to clear the EGR hardware on old vehicles that came with the 460. Just a leftover, since theres no EGR hardware installed on the Marine engines. Why they still put it on there is beyond me.

Regardless, you won't need it on your install. Gaskets are fine and I'm not a fan of re-using any gaskets anyway. 

Ray

Sounds like a low quality or severely worn Ignition switch, Ive seen them do some interesting things- motor cranks but no fire and a hot at the dizzy, Going over waves/wakes and have a intermittent stumble, etc.

X2 on a good ole NON ONE WIRE alternator.
The 37A alternator, wired right, puts out plenty of power for a squirt boat.

Dan'l

X2.....Had that keyswitch problem before a couple times......    When yu actually tear one of those buggers apart, amazing how cheap the are inside.......

Ray

I've questioned that once and the way I see it is many a 60s, 70s and 80s cars ran a carb without any marine equipment and never burnt down from fumes, and for a fact my engine on my floater is WAY more air'd out than any doorslammer. Not to mention my engine is n way better shape of a tune compared to a daily driver..ex no spark wires arcing across engine parts etc. So I'm not buying that idea, if you have a wide open engine on a boat it has plenty of air out room.
Sent from my DROID BIONIC using SoCalJetBoats mobile app

Well, you can say "I've never died from unprotected sex, so why wear a condom when with random women?" .......Same thing! 

Only takes ONCE! Trukinbear has the idea.........



Ray

As for the timing at idle it sits at 22 and with reading I've done it should be between 12-14 and at about 2500 rpm it will only advance 13 deg. I dropped it to 16 at idle and it will still only advance 13. I do have an electric fuel pump. It is also a vacuum advance dist. It has a holley 750 on it with a torker manifold. I'm going to get a fuel pressure gauge today and see how much pressure I have. Recommendations on what the pressure should be at?

OK, First, the ignition COULD be the issue with even the slightest vacuum leak. Second, did you follow rule #2? Fuel COULD be available but NOT getting into the carb.

Good setup, really (Other than the vacuum advance dizzy.......who was it on here selling a converted Olds Mallory YL/Unilite deal? Get with this kid!!!) I'd rather see an 850 on it, but a solid combo you DO have.

The last thing that will make an engine "peter out" at RPM is weak or improper valve springs. I'm really doubting that is the problem in your case. I think it is the combination of bolt on's that can fix it. Why oh WHY an electric pump? My Pickle had one, drove me nuts, it's a solution to a non-problem.......Get a good mechanical on there like a Clay Smith or a Carter Marine, and call it good for at least a decade.

Some thread on this site there is a nice, converted to Unilite, Mallory YL for Oldsmobile for sale dirt cheap. Buy it, and use it. Remove the bronze filters from your carbs, and put good in-line filters in.

I think your problems will be solved right there for under a hundo.........

Ray

Thanks GT I will try this on the weekend. Even know this is not my post its always good to here from someone else's info.

I would go with that. Fuel pressure being vital, as well as total timing. You also don't indicate a mechanical or vacuum advance distributor, just the weight set. BIG difference.

I'm gonna go with vacuum advance, since most Olds had that. Which could tie the two problems together with a simple vacuum leak.

First rule of jet boats. Dump ANY and ALL Vacuum advance Dizzy's. Worthless.

Second rule of jet boats, and I see this all the time on Holley's, a good high flow, inline filter before the pump and after, and ELIMINATE the bronze ones in the carb fuel inlet fittings. All they do is slow down flow at that point to a trickle and are designed for street engines that do not operate at the sustained RPM we do.

Now beyond those two rules, there are several. "Read your plugs, and read your plugs" and several solid others, but others you'll hear are life saving!  Like "Never believe Ralph about how fast his Family Boat is",  "Never get towed in by Brad unless it's an emergency", "Never believe Rivertard when he says 'The roost won't hurt, drive through it'", Or when he says "I'll respect you in the morning"

Never believe Hallett Dave when he says 'he approves this message" because he has NO IDEA what the message was initially. Never believe Aquaholic that the best money he ever spent was on an outdrive deckboat (The text to PROVE this is on my phone)

Take Anything we tell you with a grain of salt, as my Grampa used to say. It's VERY easy for any of us to spend YOUR money on OUR dream equipment. Some of us have ALL of that dream equipment. Some of us have experience with SOME of that dream equipment. Bear that in mind. Most are on a budget, and opt for the HEI ignition (Dumbest move ever, IMHO, and many will back me up, but the cheapest move available)

THIS is what you have to be open minded to!

RAy     

It goes right there and that's one for a 1980 460

LMAO! What's "right there"......460 intakes have 2 ports on the front of the manifold, 2 more with the right thermostat housing, the one's I'm speaking of are 3/8" NPT and will fit in any or all of them.............. 

Ray

It's the boat, not the pump.  Sounds normal.

Probably. But for chits and giggles might wanna double check your control handle, cable, reverse bucket, etc just to make absolutely sure it's not putting itself into "reverse". Very dangerous (I speak from experience on THAT one.....)

Otherwise, yeah, as Pat said, sounds like just the differences in the hulls. IE my "Moo" (A Sleekcraft Rebel) would almost stop on her own once you lifted. My "Pickle" ( A Sleekcraft SST/Streaker hybrid) would not! MANY times had to grab reverse and stab the throttle to get that boat to stop or slow down......

Equipped almost identically, it was the hull differences that can be the only reason for this.

Ray

No he'd use the terry rag that he strained his oil with to wipe the boat down, then figure out another use for it later, pats resourceful like that

LOL!

Best guess is the oil pump casting broke off and the rods bitch slapped the hell outta the pump shaft sending it outta the pan balistically. Lord knows what else you're gonna find in there though. 

Ray

if your motor is all stock yes thats what hes saying.  all intakes have a rpm range that they are premium in, a tunnel falls usually under  3500 to 6000 . That not going to work on a stock olds , or most stock motors. compression needs to be around 10.1 to 12.1 or higher. and your cam has to follow the intakes rpm wants. another words if you want to use the tunnel you have to build the motor for a tunnel.

Pretty much the jist of it. And it's the details of the engine build that determine whether a tunnel ram is advantageous or not. One fortunate thing with jet boat engines using them is we can get away with far more compression than a street engine, since we have much lower operating temps, and even more if using aluminum heads, thereby increasing not only the cool factor, but gaining everything the tunnel ram has to offer up! 

I should have been more specific on the cam selection process though. Yes, historically, blower grinds tend to work OK. But more specific off the shelf grinds are out there built on 110* or 112* centerlines with nearly non-existent overlap that are a far better choice than a blower cam at 108* and those usually have a TON of overlap (Blower pressure being constant, helps the scavaging and pushing out of the exhaust gasses as well as the new air/fuel mixture for the next cycle.....not needed or wanted on any N/A engine)

Now on an Olds? Nothing would be cooler, short of a blower! And it would take dedication and loyalty to the Olds to justify the cost in that. In point of fact, I may well do one or the other on MY Olds powered turd with an Energized Jacuzzi YJ just simply because no one else has! 

You have to bear in mind, I built and drove a boat for years painted like a Chik-Fil-A billboard..........so my pride level is a "tad" lower than most of these cats! 

Ray

I was told that the 660s cs I had were to much wouldn't 750s be going the wrong way?

I have a set of boost referenced 660's in Havasu (Harry has them) I ain't never seen, welcome to them. Another set of 660's I had I tried with disastrous results on Moo. 750 Vac Secy's were the choice, and I was running 11.5:1 Compression, and a 301* Solid lifter cam.........

Ask Nordie how well it ran......... 

Ray

  Thanks, but sure makes me feel like an old shit

Mark, we're all getting to be old shits on here! 

Ray

Yes he will.... 

Yeah, that I will......

Actually, this was a water skiing incident, and yes alcohol and a dare was involved........but we won't get into that.........

Ray