High Quality Chainsaw Bars Husqvarna Toys Hockfire Saws

Stihl ms 460/660 Hybrid. 469e

ManiacalMark

Pinnacle OPE Member
GoldMember
Local time
4:48 PM
User ID
8282
Joined
Jan 2, 2019
Messages
985
Reaction score
2,290
Location
PA
Country flag
I've had great results with just boring the choke area and not touching the throttle or venturi areas. It's all about high/low pressures and how they help to draw fuel.

Agreed, I bored the Venturi on a wj years ago, ran like shiitake, pretty sure it increased spit back too.

Also pretty sure the one Rick Hennessee 440 had a HD8 on it.
 

NateSaw

Pinnacle OPE Member
Local time
4:48 PM
User ID
26310
Joined
Mar 13, 2023
Messages
1,033
Reaction score
2,901
Location
Maryland, USA
Country flag
Working around current fueling is a poor train of thought, I’d chase air first, then mod a carb to fuel what I desire…

Modding or large carbs isn’t that a small carb can’t keep up, it’s that a larger or modded carb may allow you to either make more peak power, or move your peak power up and cut faster. Keeping a stock HD on the saw it will be constrained to warm 046 levels imo. Just a hack, take it for what it’s worth
This. I'm chasing more air. Fuel is satisfied and then some.
 

huskihl

Muh fingers look really big
GoldMember
Local time
4:48 PM
User ID
360
Joined
Dec 31, 2015
Messages
22,581
Reaction score
143,745
Location
East Jordan, MI
Country flag
This. I'm chasing more air. Fuel is satisfied and then some.
Could be in the pump itself, not necessarily on the fuel side. Seen a 79 cc echo hybrid smoke my 7900 and 500 with an HDA carburetor a little bit bigger than what’s on a 357.
 

NateSaw

Pinnacle OPE Member
Local time
4:48 PM
User ID
26310
Joined
Mar 13, 2023
Messages
1,033
Reaction score
2,901
Location
Maryland, USA
Country flag
Could be in the pump itself, not necessarily on the fuel side. Seen a 79 cc echo hybrid smoke my 7900 and 500 with an HDA carburetor a little bit bigger than what’s on a 357.
You've found my stupid. I'm afraid I don't understand... The pump? Impulse?
 

bogieboy

Well-Known OPE Member
Local time
4:48 PM
User ID
28216
Joined
Jan 1, 2024
Messages
226
Reaction score
498
Location
Rochester, NY
Country flag
Yes, I bought one from HL. Couldn’t pass it up - it was $15… We’ll see how it times out if I find a saw to put it on.
I didnt crunch any numbers other than squish.... which came out to .0205 without a base gasket on my particular saw...which is running pretty darn good i would say...LOL
 

NateSaw

Pinnacle OPE Member
Local time
4:48 PM
User ID
26310
Joined
Mar 13, 2023
Messages
1,033
Reaction score
2,901
Location
Maryland, USA
Country flag
Likely too long for most of you. This was more of a case study I guess. I worked my way down a mulberry I dropped to put it to functional use. I wanted to work the full range of throttle. I think it's safe to say the carb is fine. It's peaky. Could use a bit more torque... I'd like to spread the power band a little. I think gentle work on the lowers and uppers may be all that's needed...

 

Powerstroke Cowboy

Pinnacle OPE Member
GoldMember
Local time
2:48 PM
User ID
26178
Joined
Feb 23, 2023
Messages
1,300
Reaction score
3,858
Location
Montana
Country flag
It sounds good. Was that the low speed srew you kept adjusting or the high speed?

My opinion might not be right, but, it looks like you need more fuel from the high side. I might not be reading the signs right. But the way it seems to stall out quick and jump in the cut makes me think it's running lean on the high side.

Or your chain was just grabby?

Take it for what it worth.
 

NateSaw

Pinnacle OPE Member
Local time
4:48 PM
User ID
26310
Joined
Mar 13, 2023
Messages
1,033
Reaction score
2,901
Location
Maryland, USA
Country flag
I didnt crunch any numbers other than squish.... which came out to .0205 without a base gasket on my particular saw...which is running pretty darn good i would say...LOL
So that's with the cross cylinder, as is out of the box?
 

NateSaw

Pinnacle OPE Member
Local time
4:48 PM
User ID
26310
Joined
Mar 13, 2023
Messages
1,033
Reaction score
2,901
Location
Maryland, USA
Country flag
It sounds good. Was that the low speed srew you kept adjusting or the high speed?

My opinion might not be right, but, it looks like you need more fuel from the high side. I might not be reading the signs right. But the way it seems to stall out quick and jump in the cut makes me think it's running lean on the high side.

Or your chain was just grabby?

Take it for what it worth.
I was adjusting both. In the beginning, just getting the idle to calm a bit. Then, I was playing with high. I had it leanish deliberately, was trying to work towards a sweet spot. I think @huskihl is right, it's the pump. Being fixated on the carb, without running it more has been a distraction. However, it's been a wonderful discussion about some carb theory. And proper approaches. But yes, it was too lean. I can't blame the chain. 33rs hand filed with a 7/32 file, rakers @ 35thou. This is exactly what I run on the 446 hybrid. It's my favorite profile for ease of filing, and longevity of the cutters. It is pulling some chips, but it's not stupid aggressive. Cutting up this tree gave me a chance to work at different throttle positions. I have to say I'm pleased. All the small wood was cut at 1/4-1/2 throttle. Good response. Good gontrol. It's in the heavier wood I can see it needs more torque. It needs to be tamed a bit. I'd like to take some power from 11k rpms, and sprinkle it a little lower. While I'm waiting for the cabers, I'll do like @Ketchup suggested, and just run it. I'll try a 28" on it too. When I do get the rings, I'm going to even the uppers and open the lowers. I appreciate your input David. You aren't wrong!
 

drf256

Dr. Richard Cranium
GoldMember
Local time
4:48 PM
User ID
319
Joined
Dec 29, 2015
Messages
9,421
Reaction score
61,827
Location
Strong Island NY
Country flag
Then I vote to go to a one size smaller jet and let it rip.
It’s actually the opposite. A larger carb on less displacement needs more jet, not less. Moves less air so pulls less fuel. Happened to me with 026/044 carb swaps.

BTW, there ain’t much Venturi in the WJ.
 
Last edited:

Rich Fife

Sally slap my ass
Local time
4:48 PM
User ID
26245
Joined
Mar 4, 2023
Messages
708
Reaction score
1,065
Location
Central New York
Country flag
It’s actually the opposite. A larger carb on less displacement needs more jet, not less. Moves less air so pulls less fuel. Happened to me with 026/044 carb swaps.

BTW, there ain’t much Venturi in the WJ.
I kinda learned this on a dirtbike... with a big bore it needs a smaller jet because itll pull more vacuum/fuel. Whereas the smaller bore requires more fuel/bigger jet.
 

Powerstroke Cowboy

Pinnacle OPE Member
GoldMember
Local time
2:48 PM
User ID
26178
Joined
Feb 23, 2023
Messages
1,300
Reaction score
3,858
Location
Montana
Country flag
I was adjusting both. In the beginning, just getting the idle to calm a bit. Then, I was playing with high. I had it leanish deliberately, was trying to work towards a sweet spot. I think @huskihl is right, it's the pump. Being fixated on the carb, without running it more has been a distraction. However, it's been a wonderful discussion about some carb theory. And proper approaches. But yes, it was too lean. I can't blame the chain. 33rs hand filed with a 7/32 file, rakers @ 35thou. This is exactly what I run on the 446 hybrid. It's my favorite profile for ease of filing, and longevity of the cutters. It is pulling some chips, but it's not stupid aggressive. Cutting up this tree gave me a chance to work at different throttle positions. I have to say I'm pleased. All the small wood was cut at 1/4-1/2 throttle. Good response. Good gontrol. It's in the heavier wood I can see it needs more torque. It needs to be tamed a bit. I'd like to take some power from 11k rpms, and sprinkle it a little lower. While I'm waiting for the cabers, I'll do like @Ketchup suggested, and just run it. I'll try a 28" on it too. When I do get the rings, I'm going to even the uppers and open the lowers. I appreciate your input David. You aren't wrong!
Okay, sounds like there's more torque to be had just by fattening the mixture up. Lean makes peaky hp with less working grunt.
 

ManiacalMark

Pinnacle OPE Member
GoldMember
Local time
4:48 PM
User ID
8282
Joined
Jan 2, 2019
Messages
985
Reaction score
2,290
Location
PA
Country flag
Doesn’t seem to run too bad so far, compression feels good for running too ring only.
 

ManiacalMark

Pinnacle OPE Member
GoldMember
Local time
4:48 PM
User ID
8282
Joined
Jan 2, 2019
Messages
985
Reaction score
2,290
Location
PA
Country flag
I think for only making 4 or 5 cookie cuts it’s hard for me to judge. It cut nice in the clean log but I hit a piece of metal in it so I have to trim it and prop it off the ground.
 
Top