Am ms440 carbs

[MG porting]

Ok I've got some am carbs for the 044 and ms440 this carb I'm working on I ran in on my ported ms440 but switch it out with the HD 17a witch with that carb you can modify the jet but on this am carb I'm trying to figure out what hole to drill out bigger I circled the hole I think I need to drill out to get more fuel through the high setting any of you guys care to help me out with this please I'd appreciate it. The reason why I want to get more fuel on the high side is because it's turned out 3 and 1/4 out with the HD 14a after making the jet a smidge bigger it's right at 1 and 1/2 out.

 

[Canadian farm boy]

HD-14a is for a ms341/361. Smaller saw, less fuel, blah blah.
The aftermarket 044 carb “should” be better suited for a 044.
Maybe try the aftermarket carb before you modify it

 

[MG porting]

HD-14a is for a ms341/361. Smaller saw, less fuel, blah blah.
The aftermarket 044 carb “should” be better suited for a 044.
Maybe try the aftermarket carb before you modify it

Already did run the am carb on it that's why I would like to mod it. It runs good with it but it could use a little more fuel on the high side so that way I can get the high side adjustment nethel setting closer to 1 and 1/2 turns out instead of three mind you the sow is ported. And i ment 17a not 14a lol. Got in a typing hurry it was dinner time.

 

[drf256]

I think what you circled is incorrect.

Just verify it with some carb cleaner. See if squirting it in there makes the cleaner shoot out the main nozzle and not the H adjust hole. Shoot it in the H adjust hole and see which one it comes out of.

As you know, the wet side feeds the main nozzle via a fixed and adjustable jet. I believe we drill the fixed side when we play with these. The oem Walbro are threaded in, so it makes it easy.

Poleman has a great thread on AS about modding the Zama style 044 carbs, but I do believe they have identifiable brass plugs in them where the jets are.

Edit: the hole you circled appears to be over the H adjustment screw. I bet it’s the hole under #2

@Terry Syd @Poleman

 

[Wonkydonkey]

Subbed

How much bigger are you making it

 

[Terry Syd]

Use the carb cleaner/WD40/contact cleaner trick that 'RC' mentioned. I expect that is the hole that feeds the high speed needle.

The jet you are looking to mod is the little hole on the back of the main discharge nozzle. It works in parallel with the high speed screw. Both of them combined give the total flow through the high speed circuit.

Some carbs have a separate screw in jet off to the side the main discharge nozzle, other carbs just drill the back of the nozzle itself.

 

[Stump Shot]

Already did run the am carb on it that's why I would like to mod it. It runs good with it but it could use a little more fuel on the high side so that way I can get the high side adjustment nethel setting closer to 1 and 1/2 turns out instead of three mind you the sow is ported. And i ment 17a not 14a lol. Got in a typing hurry it was dinner time.

In a general speaking kind of way, the AM carburetor body's are copied quite well, the inlet lever springs, not even close. In my experience the best chance of an AM carb running right is to install a genuine OEM inlet lever spring. More often than not these are too stiff and will put the engine on a starvation for fuel, the longer the run, the leaner it will get. I would highly recommend this first before other mods are tried. Taking one out of an old original carb is okay, they don't go bad.

 

[MG porting]

Thanks for all the info guys unfortunately I don't have any spare springs to sacrifice Stump Shot so do you think I could snip a little off the spring to lighten it up a smidge and drf256 I'll take a better pic of other areas of the the carb and do some squrts her and there to see what happens.

 

[MG porting]

Ok here's some more pics The pin is pointing at the top of the vantery the other is me shining light into the hole that I sircled above the high speed adjustment needle and you can see the feed hole where the adjustment needle screw gos.

 

[huskihl]

That’s the main nozzle. It probably has about a .6 MM hole in it. You can drill it out to allow it to have more fuel, but I would make sure your pop off pressure isn’t crazy high with that spring. And make sure your lever is set at the correct height first. And make sure your impulse set up is working properly

 

[MG porting]

That’s the main nozzle. It probably has about a .6 MM hole in it. You can drill it out to allow it to have more fuel, but I would make sure your pop off pressure isn’t crazy high with that spring. And make sure your lever is set at the correct height first. And make sure your impulse set up is working properly

It's all good but the spring like Stump Shot mentioned there stiff.

 

[MG porting]

Ok I found that spraying WD in these two spots they both shot WD out the nozzle.

 

[Stump Shot]

Thanks for all the info guys unfortunately I don't have any spare springs to sacrifice Stump Shot so do you think I could snip a little off the spring to lighten it up a smidge and drf256 I'll take a better pic of other areas of the the carb and do some squrts her and there to see what happens.

As critical a function that little spring does, I can't recommend it. A new one can be had from Stihl.

 

[MG porting]

As critical a function that little spring does, I can't recommend it. A new one can be had from Stihl.

I'll might have to see if I can get one ordered tomorrow then and see how it works out.

 

[Stump Shot]

I'll might have to see if I can get one ordered tomorrow then and see how it works out.

Then you will know if you need to drill out or not. Don't forget to double check the metering lever height after installing, it should be dead on, not close enough.

 

[MustangMike]

mind you the sow is ported.

I'm going to have to report this to Randy, he is very concerned about the welfare of the pigs!

 

[MG porting]

Then you will know if you need to drill out or not. Don't forget to double check the metering lever height after installing, it should be dead on, not close enough.

Yep and lol yeah I know they got to be spot o for sure.

 

[MG porting]

I'm going to have to report this to Randy, he is very concerned about the welfare of the pigs!

i need me some good bacon.

 

[Lightning Performance]

If your suspecting anything is off on those carbs replace it like Stump is telling you. Good practices are to clean and reassembled and carb going on any saw here unless it just came from the builder. Even then things might still need tweaked a bit.

Cutting carb springs is BS and creates more problems then it solves. Plus any sharp edge will tear *s-word up. Don't use the thick blue diaphragm. Same problem... she said, "too stiff."

 

[MG porting]

If your suspecting anything is off on those carbs replace it like Stump is telling you. Good practices are to clean and reassembled and carb going on any saw here unless it just came from the builder. Even then things might still need tweaked a bit.

Cutting carb springs is BS and creates more problems then it solves. Plus any sharp edge will tear *s-word up. Don't use the thick blue diaphragm. Same problem... she said, "too stiff."

Lol.