ArboristSite.com Sponsors


Who knows Walbro HDC carbs?

Old2stroke

Old2stroke

Never too many toys
Joined
Jan 24, 2016
Messages
975
Location
Ottawa, Canada
I must be lucky as all the brass inserts I have pulled so far had a fairly thick bottom end to them, the thread of the machine screw barely makes a mark in the brass but holds strong enough to pull it out of the carb body. I did use a bottoming tap once but found the machine screw to be better to hold and pull the brass valve body out with. I made up a puller that a long nut on the machine screw can thread down the shaft and it applies enough force to pull the brass part out with little effort. Think of a steel bar 1/4" X 1/2" X 1.5 " long with a hole in the middle, thread the screw through the hole and then into the brass nozzle body , the bar spans the carb body resting on the outer rim , then just run the nut down. When it contacts the bar a couple turns with a wrench or pliers and the valve body pops right out undamaged. I found using a new machine screw each time gets a better hold on the valve body, I have lots of them in the screw assortment tray.
The puller is a great idea. Gotta make one. Are you really using a 6X32 tap? That would require a drill bit to be used before the tap, I've been using a taper 2X56 because it will thread right into the existing hole, might be why I'm breaking them. What is your method of getting the retainer out of the end so that you can replace the disc and still use the retainer again? All the ones I've pulled out have the rim flanged over the retainer and I'm sanding them down flush with the top of the retainer to avoid damaging it while prying it out.
 
pioneerguy600

pioneerguy600

Lost in Space
Staff member
Joined
Dec 23, 2007
Messages
41,343
Location
N.S. Canada
The ones I have pulled so far all have snap rings, like a circlip, a fine metal screen and the fiber disc trapped below the brass body, the hole near the bottom is perfect fit for a #6X32 screw. A bottoming tap can be used the same, no drilling required. I found that the machine screw does not damage the brass body as it does not cut threads very deep, hardly scratches the brass but fits very tight. When I tried to reuse the same machine screw a second time it was a 50-50 chance it would hold or slip out so I just use another new screw each time.
 
Old2stroke

Old2stroke

Never too many toys
Joined
Jan 24, 2016
Messages
975
Location
Ottawa, Canada
The ones I have pulled so far all have snap rings, like a circlip, a fine metal screen and the fiber disc trapped below the brass body, the hole near the bottom is perfect fit for a #6X32 screw. A bottoming tap can be used the same, no drilling required. I found that the machine screw does not damage the brass body as it does not cut threads very deep, hardly scratches the brass but fits very tight. When I tried to reuse the same machine screw a second time it was a 50-50 chance it would hold or slip out so I just use another new screw each time.
Great thread, I like your idea of making the disc by "drilling", rather than punching. Lots of things to try on the next crappy Poulan that comes along, they all have primer bulbs and little wee body check valves.
 
pioneerguy600

pioneerguy600

Lost in Space
Staff member
Joined
Dec 23, 2007
Messages
41,343
Location
N.S. Canada
I have made a policy of not working on many makes of chainsaws like the throwaway models of homeowner grade saws. Just me and my availibility chain of replacement parts and more so the owners of such won`t even pay for the part or parts necessary to repair them let alone any labor costs. The PRO saws are worth enough most will pay to repair them but the lower end saws of all makers usually just end up cluttering the work bench or storage area as the owners balk at paying to repair them, even just a carb kit and rebuild time exceeds their worth. I did recently refurbish some Stihl models like the 009,010, 012, 015 and 020 saws that I wouldn`t bother with years back due to them being too expensive to repair. There was a pile of abandoned complete saws in one of my storage buildings that I dug out and was pondering about tossing them, hated to but need to get some space cleared up. I rebuilt a 009 and that set up the slippery slope for doing just one more, then another and another. Still have a few more to go but if time allows they will get done by this summer and sent down the road. I like to make my own tooling for any type of work, usually my own makes work better for whatever I made them for and coming from my background its simple enough for me, ideas are always circulating in my brain for the next tool.
 
Hoggwood

Hoggwood

Dumpster saw enthusiast
Joined
Apr 5, 2014
Messages
981
Location
Okanagan, BC
For what it is worth, here is a link to a method I devised to retrofit the Walbro checks without having to pull the assembly other than the clip and screen. When complete, the retrofit check functions as new.

 
pioneerguy600

pioneerguy600

Lost in Space
Staff member
Joined
Dec 23, 2007
Messages
41,343
Location
N.S. Canada
I actually tried using your method, Hoggwood , I could get the disc out but on the first two I tried doing that way they would not seal. After pulling the brass housing out I found a rough buildup of a black rubbery material that I needed to remove and polish the surface the disc seals to, did so on a sharpening stone. Made the disc and replaced all parts, the disc would seal after doing the remove and polish. I can see the shortcut method working well if the seal seat were nice and clean but many of these old saws have gunk buildup in all areas of the fuel supply components. Thanks for posting the link and the great pics of the process, a pic is worth a thousand words.
 
Old2stroke

Old2stroke

Never too many toys
Joined
Jan 24, 2016
Messages
975
Location
Ottawa, Canada
For what it is worth, here is a link to a method I devised to retrofit the Walbro checks without having to pull the assembly other than the clip and screen. When complete, the retrofit check functions as new.

That's an easy fix for those check valves, the ones I have problems with are the smaller ones from the WT series, the brass body is only 0.185" in dia. and the disc is only 0.1" in dia. and will not come out through the 4-finger retainer which is crimped into the end of the valve body. Walbro 84-613-1
 
Top