MS460 carb on an 039

[tree monkey]

the thing is your both right and your both wrong, it really depends on what you want it to do, work or race

 

[RU NUTZ TOO]

I do simple carb mods that don't require a flow chart or a Phd. I try to bring in more air and more fuel at the H jet. That's why this thread really got my attention

one big thing through all my testing with carbs is a larger venturi is good BUT the throttle bore should also be increased and not exceed the intake boot size. this is where my thing on boring stopped. it just seems a larger carb from another application is the better solution. almost never the easiest but better. i have done a *s-word ton of testing on the 390 husky. i have now tested enough where i know for a fact the WJ39 is the carb to have on that saw. my reasoning is the venturi is larger and so is the throttle bore. the throttle bore also matches the intake boot the best out of any other carb i have tried. i've played with it and the WJ39 even makes a noticable difference on a stocker even. at first i didn't notice it much but used the 390 with the 39 on the hill for 2 days. i really got a feeling about how it ran. a few days later i swapped a 296 back on. this is where i noticed the difference. both carbs tuned to 13k and the walbro made a noticable amount more torque. i still like tilly's though.

 

[RU NUTZ TOO]

the thing is your both right and your both wrong, it really depends on what you want it to do, work or race

i'm a working man. i prefer a saw to start more then anything lol

 

[Deets066]

the thing is your both right and your both wrong, it really depends on what you want it to do, work or race

I like a strong work saw....... That had better well be able to win a few races!

 

[RU NUTZ TOO]

I like a strong work saw....... That had better well be able to win a few races!

i thought for sure you were gonna quote me saying "it sounds like you need a stihl" LMAO!

 

[MustangMike]

That is what I heard!!!

 

[Deets066]

i thought for sure you were gonna quote me saying "it sounds like you need a stihl" LMAO!

You said it, not me.

 

[RU NUTZ TOO]

WJ39 with HS296 shafts. Probably the hardest swap for the 390 but the best!

 

[Terry Syd]

If you go back and read the '7900 carb upgrade' thread on AS - http://www.arboristsite.com/community/threads/dolmar-7900-carb-upgrade.229528/

You'll see where Rich (Poleman) and I ran into the problem of too much fuel in the idle circuit (because we drilled the idle jet) and the idle became hard to adjust. We fixed that problem by drilling one of the .5mm air bleed/transition holes out to .55mm. That's all it took and the idle became adjustable.

You will also read in that thread where Rich tried the modded carb for the first time and commented on the increased torque. It made the saw a much more capable work saw.

As far as atomisation of fuel, this is a two-stroke, it has a huge egg beater in the crankcase called a crankshaft that is thrashing things around quite well. However, it is 'vaporisation' that really counts, and that is done mostly in the hot cylinder when the fuel mixture is fed into it via the transfer ports.

 

[Deets066]

View attachment 5202

WJ39 with HS296 shafts. Probably the hardest swap for the 390 but the best!

Wonder what the bore size is compared to a WJ 48?

 

[RU NUTZ TOO]

If you go back and read the '7900 carb upgrade' thread on AS - http://www.arboristsite.com/community/threads/dolmar-7900-carb-upgrade.229528/

You'll see where Rich (Poleman) and I ran into the problem of too much fuel in the idle circuit (because we drilled the idle jet) and the idle became hard to adjust. We fixed that problem by drilling one of the .5mm air bleed/transition holes out to .55mm. That's all it took and the idle became adjustable.

You will also read in that thread where Rich tried the modded carb for the first time and commented on the increased torque. It made the saw a much more capable work saw.

As far as atomisation of fuel, this is a two-stroke, it has a huge egg beater in the crankcase called a crankshaft that is thrashing things around quite well. However, it is 'vaporisation' that really counts, and that is done mostly in the hot cylinder when the fuel mixture is fed into it via the transfer ports.

it sounds like your talking about a zama lol JK terry. i had to. we can be friends i hope

 

[RU NUTZ TOO]

Wonder what the bore size is compared to a WJ 48?

well the 39 is 18.26mm venturi IIRC. the throttle bore is perfect for the 390 intake boot. after running the 39 on a stock 390 i am convinced that the they are undercarbed. needless to say, after running that 390 with the tilly after the 39 was back on there as soon as i could make it happen. very happy with it but lots of carb body mods as the tilly throttle shaft is shorter. the idle adjust also need to be moved up and over to the right in the carb body. lots to it. it's not worth buying the carbs to do it but if i had another 39 and 296 doing nothing i'd make another 390 compatible 39.

 

[Deets066]

well the 39 is 18.26mm venturi IIRC. the throttle bore is perfect for the 390 intake boot. after running the 39 on a stock 390 i am convinced that the they are undercarbed.

Undercarbed and under powered! Lol.

Nice AV I hear though

 

[RU NUTZ TOO]

Undercarbed and under powered! Lol.

Nice AV I hear though

they rag doll a 660 when both ported. i ran a 660 on the right of way a few weeks ago. i don't mind it but i always miss the full wrap on the husky. the 3/4 wraps suck!

 

[Deets066]

they rag doll a 660 when both ported. i ran a 660 on the right of way a few weeks ago. i don't mind it but i always miss the full wrap on the husky. the 3/4 wraps suck!

You just haven't ran a good ported 066 then, I have one and I know a few others that will smoke a 390 any day of the week

 

[RU NUTZ TOO]

You just haven't ran a good ported 066 then, I have one and I know a few others that will smoke a 390 any day of the week

very well could be, isn't the 660 a 94cc saw to though? it's more comparable with a 395 IIRC it's not even really about the power for me. i really like the way a 390 handles in all aspects of my job. anyways, maybe we should not derail this thread til the end lol

 

[Deets066]

very well could be, isn't the 660 a 94cc saw to though? it's more comparable with a 395 IIRC it's not even really about the power for me. i really like the way a 390 handles in all aspects of my job. anyways, maybe we should not derail this thread til the end lol

92 cc I believe. But anyway.......... Carbs, we're supposed to talkin about carbs

 

[MustangMike]

I run the Smittybilt 660s at the NY GTGs, and they are very stout! One of the two has an 054 top end, but they are both beasts!

 

[RU NUTZ TOO]

I run the Smittybilt 660s at the NY GTGs, and they are very stout! One of the two has an 054 top end, but they are both beasts!

054, you mean 056? that would be interesting.

 

[Brewz]

Pics of the carb that came off my 039

I would love some help in identifying what it is