Need help to tune an E/B 600cfm on 4.3LX

[achris]

Hi all,<br /><br />I have finally decided that option #11 is not good enough. (Sorry Bondo). I have bitten the bullet and decided to fit a new Edelbrock 600cfm marine carb to my 1994 4.3LX Mercruiser engine.<br /><br />I would love to hear from anyone who has done it before and what changes, if any, you made to the jetting. Would also like to hear the opinions of the old wrenchers about jetting. I played with jets on an old Weber 32DFM years ago, but never on a marine engine. I have S/S elbows with (I think) access holes for an oxygen probe. I may try and get one and see how I go.<br /><br />Chris..........

 

[John_S]

Re: Need help to tune an E/B 600cfm on 4.3LX

EB sells a 4.3 metering rod and jet kit, which matches the mercruiser specs. I'd start with that.

 

[achris]

Re: Need help to tune an E/B 600cfm on 4.3LX

Thanks John, I'll look into that.

 

[Bondo]

Re: Need help to tune an E/B 600cfm on 4.3LX

Carter Strip Kit,...... Part # 10-201.......<br /><br />6 sizes of Metering Rods........<br />14 sizes of Metering Jets......<br />5 sets of Metering Springs........<br />Plus some extra Needle Valves.......<br /><br />It's the Best Spent $30.00 Ever.......<br /><br />Good Luck.....

 

[John_S]

Re: Need help to tune an E/B 600cfm on 4.3LX

The Mercruiser 4.3 LX Weber settings:<br /><br />Primary Jet = 0.089<br />Secondary Jet = 0.089<br />Metering Rod = 16-6857 (68 x 57)<br />Metering Rod Spring = Yellow<br /><br />If they are part of the kit, all the better.

 

[achris]

Re: Need help to tune an E/B 600cfm on 4.3LX

Thanks guys. <br /><br />One more question. As my existing carb is a square-bore on a spread-bore manifold, will the E/B bolt straight up, or do I need an adaptor?<br /><br />Thanks......<br /><br />John,<br /><br />Those rods and jets are all in the 4.3 kit, part #1485. Thanks for the heads up on that one.

 

[Bondo]

Re: Need help to tune an E/B 600cfm on 4.3LX

Those needles,+ jets that came in My Weber were Way Too Rich,..... Raw Gas smell when trolling........<br /><br />When I got the kit, I switched to the .076/.058 rods.......The Leanest in the Box.... <br />It Cleaned the Smell up,+ I've been changing the springs to fatten it back up at speeds........<br />It's still got a slight stumble at about midrange,.. 3000rpms or so....<br />I'm going to step down to the next richer rods,+ start all over with the springs.........<br />Plugs have been looking Nice'n Brown.......<br /><br />The Kit doesn't have .068/.057 rods, but does have .068/.0555.........<br /><br />The Edlebrock has the "Either/ Or" bolt pattern.......You're good to go there........

 

[achris]

Re: Need help to tune an E/B 600cfm on 4.3LX

Thanks Bondo. This work you're doing on jetting, it's on a V6 or V8?

 

[LubeDude]

Re: Need help to tune an E/B 600cfm on 4.3LX

I think the carb is Too big for the 4.3, 500 might be about right if jetted down. Its like a 750 on a 283, just too much carb. Its going to be doggy no matter how you jet it. JMHO.

 

[achris]

Re: Need help to tune an E/B 600cfm on 4.3LX

LD,<br /><br />I was looking for around 500cfm, but Edelbrock only do a 600 and a 750 in marine. Don't got a lot of choice really. <br /><br />Chris.......

 

[Bondo]

Re: Need help to tune an E/B 600cfm on 4.3LX

Mine's a 4.3LX............ Mid 90s model.... balance shaft, but No Vortec heads.....<br /><br />I've got Them on the Shelf.... Hate to work on the current Boat, when the current Project needs so much..............