Need advice on carburator

[Blackwood80]

Hi all just after some advice on my hole in the pocket boat. I brought this boat here in Australia 2 years ago from I guy who imported it from u.s.a it is a 1994 G.W invader bravo 180 it had a volvo penta 4.3 V6 old style with 12 bolt inlet manifold and a 4 barrel Holley carb setup on it. Well I sent the boat to get rebuilt by this so called legend mechanic who rebuilt the engine but did not pick up that there was a dirty big crack in the block. So took it back to him and with lots of arguing we came to a agreement that he was going to replace the motor. Months and months went buy and he ended up closing the business down long story short I got the boat back but not complete. Hes put a newer style vortec 4.3 all looks new reman but there was no carb with the boat my and has the 8 bolt inlet manifold on it. My old set up is God knows where. This new engine has the mercarb style 2bbl carb flange on it. Here in Australia we dont have a lot of access to inboard engine parts. What I want to know is I picked up a mercarb off a 5.0 mercruiser v8 will this work on my v6 everything bolts up fine haven't tried to start it yet still waiting on a new fuel pump. Any advice would be appreciated thanks

 

[Blackwood80]

Does anyone know if the 5.0 carb will work on the 4.3???

 

[bman440440]

now keep in mind that these are my thoughts... will the carb off the 5.0 work... yes... will it be perfect... no... the v8 carb will flow more air/fuel than the 4.3 needs... I'm sure that the iboats family will have better info on this situation so I would see what the members that know the carbs better to chime in and and see what can be done to use that v8 carb.

 

[Tassie 1]

Here in Australia we dont have a lot of access to inboard engine parts. [/QUOTE]

what drongo told ya that??

5 inboards...
2 x holden 308's
2 x 5.7 mercruisers
1 volvo penta diesel

haven't had any problem getting parts

 

[achris]

Does anyone know if the 5.0 carb will work on the 4.3???

Short answer is yes. Long answer is you may need to rejet. Get the spec for the 5L carb and the 4.3L carb and have a look at the differences. If you have the carb number from the 5L I can do the research for you.

now keep in mind that these are my thoughts... will the carb off the 5.0 work... yes... will it be perfect... no... the v8 carb will flow more air/fuel than the 4.3 needs...

Not quite. The carb doesn't flow the air/fuel, the engine draws it. A 5L engine running at 2400rpm will be drawing the same amount of fuel/air as a 4.3 running at 3200rpm.... For the most part, the carb body between the V8 Mercarb and the V6 Mercarb are the same.

"Here in Australia we dont have a lot of access to inboard engine parts."

what drongo told ya that??

5 inboards...
2 x holden 308's
2 x 5.7 mercruisers
1 volvo penta diesel

haven't had any problem getting parts

Petrol Mercruisers and Volvo Pentas use USA GM base engines, which we do not get in any reasonable quantity in Australia. That 308 is a uniquely Australian engine, the USA uses a 305. The 5.7 shares many parts with the USA engine of the same displacement, but it's not the same. Try finding parts for a Merc/Volvo 4.3L engine! Diesels are a different story. And Volvo diesels are quite common in Australia.....

Chris.............

 

[jimmbo]

Deleted

 

[Rick Stephens]

I'd slap it on and go to jetting tests to make sure it isn't running too lean. A Vortec 4.3 is almost certain to be pretty happy with the jetting on a 5.0L Mercarb. Get to boating. Horrible story of spending money like crazy and never getting on the water.

 

[Scott06]

You may want to look for or buy a Holley marine 2bbl carb as that’s what Volvo used so your throttle cable and bracket will mount up. Or did the mechanic loose all that stuff too?

agree with others if you use the mercarb try it out, may have to rejet, but I’d try it and read the plugs before messing with it

 

[Tassie 1]

Petrol Mercruisers and Volvo Pentas use USA GM base engines, which we do not get in any reasonable quantity in Australia. That 308 is a uniquely Australian engine, the USA uses a 305. The 5.7 shares many parts with the USA engine of the same displacement, but it's not the same. Try finding parts for a Merc/Volvo 4.3L engine! Diesels are a different story. And Volvo diesels are quite common in Australia.....

Chris.............

as you have a lot of experience with the 4.3 l l bow to your greater knowledge of the situation re those parts, specially in Wait Awhile lol

which the OP has found no doubt,
l used to know a bloke who had 4.3's in his bertie but lost contact after retiring,

It was the premise about lack of inboard parts in general that had me scratching my head,

maybe he just had the wording wrong,
coz there's a lot of petrol inboards around, carby and efi/ mpi,

lot of places on ebay selling crate/reman donks

 

[jimmbo]

I doubt any calibration problems will be fixed by changing the main jets. Air bleeds for the off idle and main circuits, and the power enrichment calibration points are going to be wrong for the V6

 

[Rick Stephens]

I doubt any calibration problems will be fixed by changing the main jets. Air bleeds for the off idle and main circuits, and the power enrichment calibration points are going to be wrong for the V6

jimmbo, I don't think it will be far enough off for a carb going from a 5.0 to a 4.3 Vortec. The Vortec is gonna be able to nearly match the airflows of a 5L. Close enough as I'll bet it won't matter.

 

[puddle jumper]

4.3 comes with a 4 barrel carb. The 4 barrel will rate your engine at 220 hp were a 2 barrel rate you at 180/190 hp. If you find your over carberated and need some jetting tips go to your local car race track and they should be able to help you

 

[achris]

puddle jumper

"Canada more square miles of awesomeness per person than any other country on earth."

Really???

Canada population density - 3.988 people per km2...
Australia population density - 3.1 people per km2....

(Source: World Bank collection of indicators)

Just saying.

Chris....

 

[puddle jumper]

Haha what can I say. I like my country Chris

 

[Rick Stephens]

4.3 comes with a 4 barrel carb. The 4 barrel will rate your engine at 220 hp were a 2 barrel rate you at 180/190 hp. If you find your over carberated and need some jetting tips go to your local car race track and they should be able to help you

Thats nuts. Guy has had his boat for almost three years and never got it floated. He has a two barrel ready to go and you are knocking it. GO BOATING!

 

[puddle jumper]

He is asking will a 4 barrel carb work on this engine. If I’m reading this correct the 4 barrel is already attached to the engine.

 

[achris]

He is asking will a 4 barrel carb work on this engine. If I’m reading this correct the 4 barrel is already attached to the engine.

Man, you must be smoking some good stuff up there in Canada. The OP HAD a 4bbl on the original engine, but when the 'superstar' mechanic replaced it, he left it with a 2bbl manifold. He's asking is a 2 barrel from a 5 litre engine will work...

Chris.......

 

[aimlow]

4.3 comes with a 4 barrel carb. The 4 barrel will rate your engine at 220 hp were a 2 barrel rate you at 180/190 hp. If you find your over carberated and need some jetting tips go to your local car race track and they should be able to help you

True, but the only difference is at full throttle, maximum rpms. At cruise, both will be virtually identical in power and fuel usage.

 

[jimmbo]

Man, you must be smoking some good stuff up there in Canada.

I've heard some of the recently legal stuff is pretty good, but I've also heard a lot of the 'Independent' product is still stronger.


As for the OP's question. I feel the off-idle calibrations will be wrong. If it is a Holley, a different Accelerator Pump Cam might cover/mask the difference during accelerations, but not during constant RPM running

 

[Rick Stephens]

The OP must of found his own solutions. Doesn't appear to be involved in his own thread.