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-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   What carbs would you use for a stock 420 (https://www.offshoreonly.com/forums/general-q/350269-what-carbs-would-you-use-stock-420-a.html)

downforce137 10-11-2017 02:49 PM
420s had aluminum teamG Weiand intakes and GIL Exhaust.. id tell him that you want quick fuel M800s, or the 9022 Holleys that they came with..

you might see crane gold rockers thru the oil fill cap also, more indication of 420hp...

MINK 10-11-2017 02:51 PM
Originally Posted by SB (Post 4587486)
Not many mechanics (auto / boat / sled / motorcycle) know carburetors anymore. Younger generation is mostly FI. Yes, we are getting old. :)
what's a carb?

F-2 Speedy 10-11-2017 03:26 PM
IMO if you put something other than stock on it, you need to tune it with a wideband 02 sensor's, if you dont have bung holes..:picard1: in the pipes you cant, or just wing it. and hope you dont melt it down, if you have 15-1600 bucks to drop on new carbs then go for it.

BenPerfected 10-11-2017 04:17 PM
Originally Posted by getrdunn (Post 4587459)
Otherwise Holley 800 dp. I think the marine is the 8022. They ran extremely well on 454/480 hp's. Endless options really but all I can do is speak from my own experience.
Based on numerous years struggling with auto based Holley carbs, never have we been so pleased with the relativeity new Holley Marine designed carbs. The idle & mid-range circuits have been redesigned with excellent out of the box AFR’s and the idle in and out of gear while docking has been perfect without stalling. Over the years, we spent untold $ screwing around with after market carb tuners that couldn’t fix the idle issues. Today, just bolt on the Holley Marine carbs, set the idle RPM in gear & go boating.
Ben

Baja Rooster 10-11-2017 04:39 PM
Originally Posted by MINK (Post 4587488)
what's a carb?
According to my girlfriend it's what I'm not suppose to eat because I'm getting chubby.

Does anyone know a good mechanic for a horseless carriage??? Asking for a friend.

getrdunn 10-11-2017 05:03 PM
Originally Posted by Mr Maine (Post 4587466)
Stock is 800 double pump holley 9022. 76/87 jets i believe
thought I was off a number. Either way these work great with a little tuning and staggered jetting. Some guys don't like them however they worked great my app.

Rookie 10-11-2017 07:29 PM
Even on the Holley automotive carb calculator they call for a min 750. In a marine environment they call for a little more cfm than automotive. Tell the dealer to put back on what Merc R&D put on there. They are great running and bullet proof engines when maintained properly. No reason to reinvent the wheel.

formula1 10-12-2017 11:09 AM
Originally Posted by Rookie (Post 4587532)
Even on the Holley automotive carb calculator they call for a min 750. In a marine environment they call for a little more cfm than automotive. Tell the dealer to put back on what Merc R&D put on there. They are great running and bullet proof engines when maintained properly. No reason to reinvent the wheel.
Exactly the reason I posted this thread. Thanks for all the replies! I'm going to go call him and tell him 2 Holley Marine 800's please!

BenPerfected 10-12-2017 08:40 PM
The 370 HP 454 Merc’s were Rochester Quadrajet carbs. The 420 HP were Holley carbs.

formula1 10-13-2017 10:30 AM
Originally Posted by BenPerfected (Post 4587711)
The 370 HP 454 Merc’s were Rochester Quadrajet carbs. The 420 HP were Holley carbs.
Yeah, I just heard back from Formula, it came with 420's, So, it looks like I need Holley 800's.


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