440 mod question

JTinaTree · Dec 4, 2006

I am putting a Dual port cover on my 440 ,Can you retune carb settings accurately without a tach? Also Is it necassary to read the plug after I richen the high speed screw, As I have read on here that you will have to richen the carb after a muffler mode, because it will run leaner ie more flow with dual port. Thanks for your input in advance

ciscoguy01 · Dec 4, 2006

Fyi

I did, doesn't mean you should though. If you have a stihl dealer locally he'll probably tach it for you for very little. I modded my muffler on my 044, I tuned the H down a little, and I've been very adament about checking my plug to make sure it's burning light brown, I don't like white burning... I also look inside my muffler quite frequently to see what color my exhaust is coming out, if there's a ton of black sooty buildup it's prolly running too rich... Just my .02 :cheers:

Lakeside53 · Dec 4, 2006

Yes.. The 440 still sounds like it should when tuning by ear... All you are going to do is slightly open up the H screw (counter clockwise). With a stock DP muffer front, I doubt it will be to lean at 1 turn out.

I ignore my plugs for the most part... If it's running right, they will be in the range of acceptability..

JTinaTree · Dec 5, 2006

Thanks for the info I will try it and reply back...

Kneejerk Bombas · Dec 5, 2006

Does your saw have limiter caps on the adjusment screws? If so, you'll need to get them off to get enough adjustment. If you don't know how to adjust the carb, you should take the time to learn, get a tach, or have your local shop tune it (if they know how).
Opening the exaust makes the saw run leaner. Running the saw too lean will burn up the piston (a bad thing).

ciscoguy01 · Dec 5, 2006

Umm

Mike Maas said:
Does your saw have limiter caps on the adjusment screws? If so, you'll need to get them off to get enough adjustment. If you don't know how to adjust the carb, you should take the time to learn, get a tach, or have your local shop tune it (if they know how).
Opening the exaust makes the saw run leaner. Running the saw too lean will burn up the piston (a bad thing).

Good reason to put a BB kit on it though, lol...