I'll open up a new thread (yeah, I jacked the other one.) 

Question for you folks... I'm ditching my Q-jet and bought a Holley 800dp (4150, 9022).  I'm a newb on this so bear with me.  To make this change I'll need the spreed bore/square bore adapter, new gasket, and fuel log.  Anything else?  What about the carb spacers... any advantage to these?  Holley says this should work out of the box, is this true?  Any tuning needed?  If it needs tuning what really needs to be done except adjusting idle?  Any takers to help a brotha out   ?  Free beer and stripers (well the beer at least.)

Thanks!


beerjet, thanks for the feedback.

Where do you take it out to tune it?

OK, this is what will probably happen when you put it on. When you goose it with a Jet, you probably will have a hesitation / bog for a second. This is becuase a jet boat needs very little acc pump, but most carbs DP's are designed to hit some kind of limiter (IE the torque convertor or prop). No big deal if you have this happen (try it first, it may already have a mellow pump cam) just get an Acc pump tuning kit and put in the pink cam to the primaries, and the green in the secondaries and see where that gets you.

You will need more acc pump the higher the carb sits. Open spacers will help top end, 4 hole will help the bottom end.

What manifold are you using?

The acc pump covers up the fact the engine can't rev to WOT potential and the fuel takes a while to get flowing from the mains. With the engine effectively unloaded due to the jet's design, the pump shot can rev the engine quite high, high enough to pull on the pri/sec mains almost immediately.

In a car, the lower the stall, the bigger the pump shot for a given carb.  My 12 second van with 1800 stall, needs a decent size pump and squirter in the primaries, and a HUGE shot in the secondaries so it doesn't bog off the line. 

My 9 second duster with a 4500 stall has about 1/2 the pump shot volume the van needs.

The single carb I have setup for my jet, has the smallest cam available, backed off a bit on the adjustment, with a std size 31 squirter.

It probably goes without sayin but I'm going to anyway, thats the same carb I put on first of the year, the only issue I had was the chock fell shut. When you open it manually it feels like it takes enougph force to open I didn't expect it to fall shut with the motor runnin.(but it did instantly) There's probably a better way, but I just took the butterfly completly off.

If you do that, you decrease the pump duration, but the CC's stay the same. With an aggressive initial shot, the engine will rev quicker,  however too much will bog it too. You have to find that balance between enough fuel and too much.

If it sputters then goes - squirter size
If it goes, sputters, then goes again - pump shot.

Normally with a car, you start small and work your way up from the stock settings.

With a Jet, Start at stock and work your way down. If a problem appears or engine acceleration gets worse, only then start going up. Most jets are not going to have a problem of not enough pump shot. YMMV

  Speedy !!  A Blue Oval site    Are you starting to see the light 

 jk  thanks for the link, cool info.

Don't get your hopes up...

Then again, I'm starting to realize why you run dial-up. After all, it takes a lot of cash to keep that BBF runnin'! 

 Shut up Jetaholic !!!  Grown-ups are talking !!! 

Can't handle the fact that it takes a real man to wear a bowtie? What a bitch!!! 

  ??   Did you forget who your talking to   ??

http://www.socaljetboats.com/index.php/topic,1946.0.html

Speedy !!  A Blue Oval site    Are you starting to see the light 

 jk  thanks for the link, cool info.

heh heh - if you only knew.... it's the other way around....

It probably goes without sayin but I'm going to anyway, thats the same carb I put on first of the year, the only issue I had was the chock fell shut. When you open it manually it feels like it takes enougph force to open I didn't expect it to fall shut with the motor runnin.(but it did instantly) There's probably a better way, but I just took the butterfly completly off.

A jet really doesn't need a choke, esp if you have a hand throttle.

There is an adjustment for the mixture on the side (on electrics you loosen and turn the entire black canister), as well as an idle screw for the choke (bottom access 5/16 screw, only visible at WOT when mounted with electric choke). If you leave the choke on a carb, play with the mixture setting, but back off the idle speed. No one needs to be idling at 1700 rpm at the docks waiting for the choke to come off.

His carb, if it's like mine is a manual. and when you opened it it gave me the "fantasy" it wasn't goin no where. I was wrong

Finally in.  Ain't she purdy    Just waiting for the fuel lines....





since 1903

... bought a Holley 800dp (4150, 9022)...