254 Husky with a HDA 120 carb

[DustyRanger]

Hey Gents - Firstly, I been reading threads from this site for over a year. Thanks to all for sharing your collective wealth of knowledge. This is my first post so let me know if I screw up.
I jumped in and modded one of my 254's (ported intake and exhaust, matched all gaskets,muff, heat sheild, etc to the new port sizes, muff mod, new piston and ring, opened up the air intake elbow and used a slightly thinner jug gasket.) Obviously, this site has had a bad influence on me. She's running a little rich on the idle. So much that I cannot reduce the chain to a stop with the throttle adjustment screw. Same problem before the mod. Yes i put a carb kit in it (including welch plug). I don't have a sonic cleaner but let it soak 2-3 days in Sea Foam before blowing out all passages. Pressure checks were good. I readjusted the needle lever slightly below level.. no change. The H needle is set at 1 1/4 turns out and 4 strokes nicely, cleaning up in the cut. The L needle at 1 1/2, leaned to peak rpm and then turned back in 1/4 turn (as per specs). Unless I missed something obvious, I thing this carb is toast. So...thinking of replacing this carb (walbro HDA 35 ) with a larger venturi model (HDA 120 or 87 if I can get my hands on one). Has anyone tried either of these carbs on the 254 and did you make any gains? Thanks again!

 

[nmurph]

A rich setting will result in a lower idle not a higher idle speed. Try backing the L out some, that should reduce the idle.

 

[funky sawman]

jacob j member on this site knows 254's very well, need to get him to tune in.

 

[firefighterwolf]

Hey Gents - Firstly, I been reading threads from this site for over a year. Thanks to all for sharing your collective wealth of knowledge. This is my first post so let me know if I screw up.
I jumped in and modded one of my 254's (ported intake and exhaust, matched all gaskets,muff, heat sheild, etc to the new port sizes, muff mod, new piston and ring, opened up the air intake elbow and used a slightly thinner jug gasket.) Obviously, this site has had a bad influence on me. She's running a little rich on the idle. So much that I cannot reduce the chain to a stop with the throttle adjustment screw. Same problem before the mod. Yes i put a carb kit in it (including welch plug). I don't have a sonic cleaner but let it soak 2-3 days in Sea Foam before blowing out all passages. Pressure checks were good. I readjusted the needle lever slightly below level.. no change. The H needle is set at 1 1/4 turns out and 4 strokes nicely, cleaning up in the cut. The L needle at 1 1/2, leaned to peak rpm and then turned back in 1/4 turn (as per specs). Unless I missed something obvious, I thing this carb is toast. So...thinking of replacing this carb (walbro HDA 35 ) with a larger venturi model (HDA 120 or 87 if I can get my hands on one). Has anyone tried either of these carbs on the 254 and did you make any gains? Thanks again!

One of my 254's - muffler modded only - HDA-35B Carburetor
H = 1-1/4 Turns
L = 2 Turns

A rich setting will result in a lower idle not a higher idle speed. Try backing the L out some, that should reduce the idle.

nmurph is correct.

 

[DustyRanger]

When I open up the L more, she drops in RPM as per usual but smokes bad and had fuel coming out the muffler which I'm guessing indicates to rich a mixture. She also bogs on the throttle response. I also checked the clutch springs to make sure they were not broke or week, causing chain rotation. I will try nmurph's suggestion again tonight to make sure. I do know one thing, I can take the carb off this saw now in record time blind folded!

 

[nmurph]

Then replacing the springs sounds like it should solve the problem.

 

[jammin_with_j]

DustyRanger, are you the person with the listing up on the local classifieds looking for the HDA 87 or 120 carb?

 

[jammin_with_j]

When I open up the L more, she drops in RPM as per usual but smokes bad and had fuel coming out the muffler which I'm guessing indicates to rich a mixture. She also bogs on the throttle response. I also checked the clutch springs to make sure they were not broke or week, causing chain rotation. I will try nmurph's suggestion again tonight to make sure. I do know one thing, I can take the carb off this saw now in record time blind folded!

If you can't get that carb fixed, I've got a used HDA 35 carb

 

[DustyRanger]

If you can't get that carb fixed, I've got a used HDA 35 carb

Hey J - fellow "Blue Noser". Yes -that is me. I have another used HDA 35 that I can try but would have to put a carb kit in it. I figured if I was going to try a bigger carb (HDA 87,120 or 144) I would have to put a kit in that one as well. I only have one kit left so figured I see if a bigger carb surfaced before kitting out another HDA 35. (I believe all these models take the same carb kit). Make sense? Thanks for the offer but will hold off for now.