McCulloch Chain Saws
- Thread starter Bruce Hopf
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I tried it with only one diaphragm & it wouldn't hold any pressure,so I put the 2nd one in.It holds pressure,but won't give me more than a pop.If I could find a Walbro SDC20 I'd put that in & see what happened,but I can't find one.If there's another carb that'll work I'll use that.
I hope you can clean it without any problem.
The pressure should be also checked by the needle and seat also, I feel like you might be blocking instead of sealing?
Following the advice of the fellows who have the most experience with this I recoat the SP81 tank ,but thinned it out just a little bit too make the process of coating easier.
Being that I don't want to do this AGAIN I cleaned out the tank joint with a knike and dremel stainless steel wire wheel and epoxied the seam from the outside . I'll sand the epoxy smooth in a couple days and it'll give the tank a one piece look.
I figured if the SC sun can burn the paint off the roof of my old 300.00$ jeep it'll help cure everything up nicely.
might wanna let it cure @ room temp, rather than cookin some of it
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They are, especially when the reeds fully open up. It's like a shot of nitrous.
Never mind, I accidentally stripped out a muffler bolt hole while trying to pressure/vacuum test it. Now I have to decide, Helicoil it or use a tap to make it the next size up?
A friend put helicoils in my 110 when that happened, seems to have worked OK.
Time-sert is how I fixed my stripped exhaust mounting point on my PM800. No problems since. Brian T. uses them all the time and graciously helped me out with the insert and necessary tools. Maybe you can find someone local so you won’t have to make the investment.
Ron
Ron
GoBigRed
ArboristSite Operative
I know the 10-10 and 55 do. I would assume the same
For the 700. As far as I know it was only the bore that changed for that family of saw. Mcculloch kept them all very similar and interchangeable for parts. Heck, folks take a 700 jug and piston and swap it out on a regular 10-10a. Makes a great sleeper saw
Jaygettinstarted
ArboristSite Member
I have a pro mac 10-10. Was told its a '78. And i use it every chance i get!
There were two different bearing and seal options used on the flywheel side of the 10 Series saws. Most have the hard to find 63429 bearing on the flywheel side with the 61618 seal that presses into the wider outer race of the bearing. Others use the same bearing and seal combination as the 600 Series saws with the 67905 bearing and 67906 seal, the bearing in narrower and the seal matches the O.D. of the bearing and presses in side by side. The two are completely interchangeable as a combination. Most 10-10 models use the 67905/67906 combination as well as other random saws along the way.
The PTO side all use the same bearing and seal, 104357 needle bearing and 110260 seal. The 60 cc and larger saws have a sleeve or insert that the bearing and seal press in to and are positioned in the crankcase with either a dowel pin (later models) or a snap ring (earlier models). On the 54 and 57 cc models the bearing and seal press directly into the bore of the crankcase.
Mark
The PTO side all use the same bearing and seal, 104357 needle bearing and 110260 seal. The 60 cc and larger saws have a sleeve or insert that the bearing and seal press in to and are positioned in the crankcase with either a dowel pin (later models) or a snap ring (earlier models). On the 54 and 57 cc models the bearing and seal press directly into the bore of the crankcase.
Mark
drumbum
ArboristSite Operative
Thanks mang.
drumbum
ArboristSite Operative
Thanks much Mark.
Camperspecial
ArboristSite Member
Thanks Mark, for the idea of using stainless tig fill rod for throttle linkage. Worked great. Bought one pound of 1/16” (lifetime supply) at local welding shop for $15.
Tip: As it comes, it is super springy and hard to bend.
I heated the length of the rod with a propane torch to red and let it cool at room temperature. Bends and holds shape a little easier.
Tip: As it comes, it is super springy and hard to bend.
I heated the length of the rod with a propane torch to red and let it cool at room temperature. Bends and holds shape a little easier.
I did like you said Ira & took the tan pump diaphragm out & then did a pressure test & it held pressure.I put the carb back in the saw & it wouldn't fire - no spark.I pulled the recoil off & went through the wire (they looked kinda iffy from the start) & I found a bare spot on the kill swith wire where it goes into the recoil.I put a piece of fuel line on it & found the points wire was off the coil as well.Once the wiring was fixed it fired right up.The wiring was the culprit right from the start,probably wouldn't have had to rebuild the carb,but it's running a bit leaner now.No more excessive smoke out the exhaust.It throttles up nicely & idles well too,I'm happy again,Lol.
I was watching a video with Donny Walker talking about Mac carbs, he said it's not a good idea to leave out the tan diaphragm.
The tan skin is ethanol resistant or used as a stiffer back up on the rubber diaphragm, the worst that could happen is you get too much fuel pumping.
I basically add the tan skin all the time, but that carb sits directly on the impulse port , the 125 dosen't. The farther you move the carb away from the port the more diffused the impulse signal is going to be.
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