Okay I have a question, went from a 1" to a 2" carb spacer, in what way should that affect wot rpm??? I haven't checked just yet to see if I'm hittin wot without it runnin but thought I adjusted the cable daily close, normally my rpm hits 5200-5250, slapped the spacer in,(again not sure if I'm hittin wot) but noticed it tops at 5k now.. Just a question...


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It would not surprise me at all if it was the spacer keeping it limited.

When large volumes of high velocity air go through any venturi,  the shape has everything to do with how the air will form a shape and actually block itself. All things being equal, it can also effect the fuel ratio because of the way the air has changed through the carburetor.

That being said,  weather conditions can also adversely effect the performance.  Temperature,  humidity,  barometric pressure are just a few things that screw the air up.

This is why we always try to test a few different things at one time. The weather will play hell.

Well let me start with the 1" spacer, I pulled the carb, which is just an edelbrock 750, the gasket under the carb(on top of the 1" spacer) was covering at least a quarter of the secondaries opening and also a 1/4 of the primary, so I added the new 2" spacer with proper gaskets and I noticed at wot once last weekend (up at silverwood which is higher altitude) that it almost seemed like it ran outta fuel. It lean pops a bit every time I'm there,even with the 1", seemed to not do it as much with the 2",but does Bitchin at the river, no pops, granted could have been my foot liftin a bit in the chop but first thing in the mornin on glass it still only spun 5k....haven't had it at the river with the 2" yet but goin in two weeks, I think I'll take the 1" too and try that with the correct gaskets as well


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A lean pop has nothing to do with the spacer, unless it is really changing the velocity.. (doubtful)

Which Edelbrock carburetor? Have a number? These are difficult to get to work right...

GT

That is a trick carburetor to get to work, it is basically a re-pop of the earlier Carter AFB, most important to get it to work on a jet boat engine is the secondary main jets and the pick up spring rating. I think if memory serves we normally use the blue ones.

This type of carburetor thrives on mid stage acceleration, so to get it to operate on WOT with low vacuum is the challenge. I'm not sold on the idea of a 2" spacer because of the way the carb top is designed. I could be FOS.

There are about twenty-five different adjustments you can make to these guys not including idle. Not for the faint of heart.

I believe you can buy a kit for these still, Carter called it a Strip-Kit... I will try to look it up and see if it is still available. Edelbrock in their genius marketing have changed almost every part just enough so it wont work retro active... Awesome.

GT

I actually haven't had any issues with the carb at all, thing is turn key every time, was just curious about pros and cons of the extra inch on the spacer.


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