It's MS461 Time In Tennessee

[MustangMike]

T

The hd50 has a main jet that delivers x amount of fuel at wfo regardless of the H screw setting. The H screw just adds a small amount of fuel to fine tune the high side. They deliver added fuel as soon as the jet is cracked open out to about 4 turns out. Drill the main jet too big and the saw will always 4 stroke even with the screws in tight. Drilling the jet or replacing it won’t give more power, it just gets you back inside the tuning range of the h screw, like somewhere between the preferred 1 and 2 turns out.

To get more power or rpm you’d need more air, as in bigger venture in the carb. Or create a controlled air leak somewhere if the carb can deliver enough fuel to support it

Thanks for the detailed information Kevin. In theory, I agree with everything you say, but in actual testing on different saws, some seem to prefer one carb over another, and I can't explain why.

One of my ported 460s noticeably gained cut speed with an HD-50 carb, while my other two ported 460s did not like it at all, nor did my CFB Hybrid. I can not explain the results, I'm just saying what happed with timed cuts in Hickory that I conducted on my saws.

 

[RI Chevy]

TY Kevin. Very informative.

 

[huskihl]

T


Thanks for the detailed information Kevin. In theory, I agree with everything you say, but in actual testing on different saws, some seem to prefer one carb over another, and I can't explain why.

One of my ported 460s noticeably gained cut speed with an HD-50 carb, while my other two ported 460s did not like it at all, nor did my CFB Hybrid. I can not explain the results, I'm just saying what happed with timed cuts in Hickory that I conducted on my saws.

No idea. Given the choice , I’d have every carb shut the fuel off when the screws are tight. More simpler

 

[RI Chevy]

Interesting how the internals work on these carbs.

 

[MustangMike]

And the majority of saws I tested seem to prefer those carbs … but not the one 460!

 

[Deets066]

And the majority of saws I tested seem to prefer those carbs … but not the one 460!

You think it’s possible your times were swayed by something other than the carb?
Possibly?
Maybe?

 

[huskyboy]

The hd50 has a main jet that delivers x amount of fuel at wfo regardless of the H screw setting. The H screw just adds a small amount of fuel to fine tune the high side. They deliver added fuel as soon as the jet is cracked open out to about 4 turns out. Drill the main jet too big and the saw will always 4 stroke even with the screws in tight. Drilling the jet or replacing it won’t give more power, it just gets you back inside the tuning range of the h screw, like somewhere between the preferred 1 and 2 turns out.

To get more power or rpm you’d need more air, as in bigger venturi in the carb. Or create a controlled air leak somewhere if the carb can deliver enough fuel to support it

Kev is the 394 and 395 walbro carb set up similarly to this? I’m shocked to see .56 and .62 main jets in the WJ39 and WJ115. One of the 39’s I have here even has no hole for the H main jet to the chamber, it’s cast shut by the appearance of it. But they both seem to feed pretty good, especially on a stock saw your only 3/4 turn out usually.

 

[Spladle160]

You think it’s possible your times were swayed by something other than the carb?
Possibly?
Maybe?

Probably need a dyno to know for sure....

 

[MustangMike]

You think it’s possible your times were swayed by something other than the carb?
Possibly?
Maybe?

I swapped the carb on the spot, same day, don't know what I could have done to make it less dependent on other factors.

Confirming my assessment, that 460 faired very well in the Upstate NY competition with the HD-50 carb. Most of my other saws will not run as well with that carb. Sorry I can't think of a valid explanation as to "why".

 

[Mastermind]

This group of saws is blooming.

10 MS461s, a 066, and a MS660.

 

[Nutball]

2-3 look used, are you doing used saws now?

 

[USMC615]

2-3 look used, are you doing used saws now?

I'm gonna send Monkey Man a used Wild Thang...and he better not 'Return To Sender' until it's stuffed with little nanners!

 

[Mastermind]

2-3 look used, are you doing used saws now?

I've never stopped doing used saws for repeat customers. These are low hour units from people I know.

The 066 is a fresh rebuild on a clean old saw.

 

[Mastermind]

I'm gonna send Monkey Man a used Wild Thang...and he better not 'Return To Sender' until it's stuffed with little nanners!

Who are you again?

 

[USMC615]

Who are you again?

 

[sawmikaze]

Your threads come in at #2 for best derails.
@sawmikaze still is #1

It's nice to come in 1st place for something other than my smile.

But my threads aren't on topic to begin with so it really doesn't matter.

 

[huskihl]

Kev is the 394 and 395 walbro carb set up similarly to this? I’m shocked to see .56 and .62 main jets in the WJ39 and WJ115. One of the 39’s I have here even has no hole for the H main jet to the chamber, it’s cast shut by the appearance of it. But they both seem to feed pretty good, especially on a stock saw your only 3/4 turn out usually.

See the brass jet in the middle with the hole in it?



That’s also the main nozzle.



To the right of that jet though, is an h side feed hole for the screw. So the #56 jet is always allowing that much fuel through, regardless of your screw setting. And when you open the h screw it flows down through that hole to the right and around the screw tip and back into the main nozzle in addition to what the #56 jet flows.

 

[Mastermind]

See the brass jet in the middle with the hole in it?

View attachment 249810

That’s also the main nozzle.

View attachment 249811 View attachment 249812

To the right of that jet though, is an h side feed hole for the screw. So the #56 jet is always allowing that much fuel through, regardless of your screw setting. And when you open the h screw it flows down through that hole to the right and around the screw tip and back into the main nozzle in addition to what the #56 jet flows.

I just did some Echo 590s with that arrangement. They wouldn't make it to 13000 with the H screw closed. So.....I filled that hole in the nozzle with epoxy. Then..... 14,200 with the H at 1.5 turns out.

 

[huskihl]

I just did some Echo 590s with that arrangement. They wouldn't make it to 13000 with the H screw closed. So.....I filled that hole in the nozzle with epoxy. Then..... 14,200 with the H at 1.5 turns out.

I had a 288 that was set up the same way. Although it may have been like a 461 with the separate main jet. It wouldn’t lean out to where I wanted it. I soldered the jet shut and just ran it off the screws. 1.25 turns out

 

[Redfin]

See the brass jet in the middle with the hole in it?

View attachment 249810

That’s also the main nozzle.

View attachment 249811 View attachment 249812

To the right of that jet though, is an h side feed hole for the screw. So the #56 jet is always allowing that much fuel through, regardless of your screw setting. And when you open the h screw it flows down through that hole to the right and around the screw tip and back into the main nozzle in addition to what the #56 jet flows.

I want to like those pics but your fingers are taking to long to load.