Just a quick jetting question.
 

I'm curious at what some of you guys running N/A 540's are running for jetting in a single carb application.
I originally had 92 squared (1050 Dominator) and ran the boat in some really cold weather (48deg.) and the boat really picked up and the plugs still looked fat.
This summer I put 91 sq. in and seemed fine, but the transom is still getting some black on it. Now I can read plugs pretty good , but most of my tuning is with 2-strokes , with the boat and unleaded gas it seems kind of hard.
Well I decided to try 90's and wonder what you guys think ?

Im so sick of screwing with jets Im ready to put aftermarket headers on the boat just so I can mount one of these:

http://www.racetep.com/halmeter.html

If you have a dry place for the weld nut....do it and be done.

26scarab, are you taking plug readings at various rpms??? You should take some at cruise speed and some at WOT. The cruise speed plug readings(w/o secondaries open) will get the jetting for the primaries. Run at about 100 rpms less than where the secondaries open. Get them set up first. You may be rich or lean in either the primaries or secondaries and be compensating for it on the other side. Go from there for the secondaries.

jetting
 

26scarab
I run a 565 with a 1050. I have O2 sensor and pyros. I am currently using 83 jets in front with 5.5 pw and 93s in rear with 3.5 pw. seems to work fine. Hope this helps
John

26 scarab;

I had a built N/A 502 (600-625hp) in a previous boat with a Nickerson 1050 Dominator, I ran 82's in the primary and 88's on the secondary..no power valve.

Thanks for the replies, I think I'm going to be safe with the 90's.

Griff,
I have done the testing like that. and with the Dominator the secondaries open with the primaries, its not like a vacuum secondary carb.
The problem is I don't get allot of color on the plug , the color I do get is a light grey. When tuning the sleds I look for a light tan color (on porcelan) or look at the piston wash which is about impossible to do on the boat.