HPbyGD

If those are the IFR's up that high aren't they above the fuel level ?

Gary

speedtigger

iTrader: (16)

You have to look at the way the metering plate is designed. The fuel has to be pulled up to above the float level by engine vacuum then back down to the idle screws and discharge port. Otherwise, fuel would drain into the engine when it was not running. If you look at the other side of a factory metering block, you will see better how it is built.

Pop N Wood

iTrader: (1)

Here is a nice lexan metering block. Not sure if it is the HP version or the traditional version. I would post the image but it is huge.

http://www.performanceboats.com/atta...0&d=1281039339

speedtigger

iTrader: (16)

That is a great visual aid.

gjestico

iTrader: (5)

On my 770 Ultra avenger (new last year) the IFRs' are in the lower area as shown above. The stock orifice was .035 and I had to add a .009" wire in them to get my idle/cruise afrs' lean enough. it would run 12-13 before I did this.

speedtigger

iTrader: (16)

Finished up customizing my 950 HP today.

As delivered from Pro-Systems the jetting was 76/86 with a primary powervalve control feed restrictor of .055". As delivered, high speed cruise produced an a/f ratio of about 12.5:1.

I jetted it down until cruise at 2800 RPM was about 14.0 to 14.5:1. That gave me #70 primary main fuel jets.

Then to get my WOT A/F ratio back to 12.8-13:1, I ended up drilling the PVCR to .072".

I found that this carb moved about 1/2 of a point A/F ratio for every .005" that I drilled the PVCR.

Now this carb idles and drives every bit as nice as my old 750 did, cruises clean and runs hard. I am a happy camper.

streetknight2

iTrader: (10)

Thanks a lot for posting Tigg, sounds like our carbs are identical out of the box and on how they react. Mine has same setup as yours (before your kids) and mine idles 12.5ish and wot 12.8-13.2:1. Looks like I got some kids to do too