365/372XP mixture adjustments on Walbro HD-12B carburetor

[Todd Noel]

Hi guys,
I recently built a Farmertec repair parts kit into a nice clone saw. I replaced the Chinese carb (among other parts) with a brand new Walbro HD12B. Saw is a ripper! Only problem I'm having is making carb adjustments is a bitch since I cut all the carb limiter crap off the adustment needles. The adjstment slots in those screws are so small it's impossible to get a screwdriver to fit throught the support sleeve "tunnels" and actually engage them. You can't feel what you're doing and the vibration makes it even harder. I have to take the filter cover off, remove the support sleeve and hold the screwdriver in the slot by hand while making running adjustments. I managed to pull it off but dread having to go through this process every time I need to make adjustments...
Here's the question: Does anyone know if Walbro HD-6B needles have normal size slots? Could they be substituted for the ones in my HD12B? Or is there a tool that would slide over the slender needles and stay in place while making adjustments?

Thank You, Todd

 

[huskihl]

Buy new limiter caps and put them back on and just trim the tabs off

 

[Todd Noel]

Probably the best advice Kevin. I should have waited before ordering HD6 needles. Maybe they'll work, maybe not. Well at least I have a backup plan.

 

[huskihl]

Probably the best advice Kevin. I should have waited before ordering HD6 needles. Maybe they'll work, maybe not. Well at least I have a backup plan.

Yeah I don’t know if they will work or not. Part of what makes some of these carburetors EPA carbs is having larger fixed main jets and smaller variable jetting so that 1/2 turn doesn’t make much difference in the amount of fuel sent. But they might work

 

[Todd Noel]

I don't think

Yeah I don’t know if they will work or not. Part of what makes some of these carburetors EPA carbs is having larger fixed main jets and smaller variable jetting so that 1/2 turn doesn’t make much difference in the amount of fuel sent. But they might work

I don't think this carb has a fixed main jet as it's high and low speed needles adjust normally-or at least the same way as in my past experiences. Very close to one turn out for both after adjustment. Saw is quite sensitive to small adjustments of the idle jet. Idle speed adjustments affect the low speed needle and vice versa. just as I've always experienced in the past (Stihl 026, Homelite Super XL Auto, etc.). High speed needle tunes normally. Set kind of rich right now as I'm still breaking in the Hyway big bore, pop up, Titanikel and Caber combo. Just wish I hadn't gone all ninja on the limiter caps before I knew what I was getting into...

 

[steele_109]

I think you can cut the slots off and use a splined carb adjuster to make your adjustments.You have to open the holes on the cover to get it in.But the splined driver gives a positive lock on the adjustment needle.

 

[Todd Noel]

I think you can cut the slots off and use a splined carb adjuster to make your adjustments.You have to open the holes on the cover to get it in.But the splined driver gives a positive lock on the adjustment needle.

Yeah, I have a set of those drivers and was wondering if the "18 spline" would fit. Was trying to avoid having to open up the holes though. Going to wait and see. It is an option.

 

[huskihl]

Never seen any of the drivers fit jet heads under the caps. There are so many different diameters of splines underneath the white, black, and red caps that I don’t think it would be on purpose if one did work. I’m certain of at least 4 different size IDs on the jet caps and I only know of two splined driver sizes.

 

[ChickenPappy]

Never seen any of the drivers fit jet heads under the caps. There are so many different diameters of splines underneath the white, black, and red caps that I don’t think it would be on purpose if one did work. I’m certain of at least 4 different size IDs on the jet caps and I only know of two splined driver sizes.

There are three splined drivers for the Walbro carburetors now. The newer one is a 20 spline 5mm tool, I believe that’s right.

 

[huskihl]

There are three splined drivers for the Walbro carburetors now. The newer one is a 20 spline 5mm tool, I believe that’s right.

Yes. It’s the newest one and it’s used on the 585 and I believe the 455. Not certain on the 455 tho.
But the dealer cant legally sell them. Last I heard they were back ordered

 

[9050LX]

I had a small engine repair mechanic tell me it was illegal to sell the splined screwdrivers. I told him they sell them all over E-bay. I don't think he knew.

 

[huskihl]

I had a small engine repair mechanic tell me it was illegal to sell the splined screwdrivers. I told him they sell them all over E-bay. I don't think he knew.

Chinese aftermarket are available on eBay, but not oem tools from a dealer. They don’t have to comply with either the tools or the saws for whatever reason

 

[thompsoncustom]

Why not just pull the needles and cut bigger slots in them? I've cut the head's down by half before and then made my own slots before when fixing a bigger carb.