MCCULLOCH The official McCulloch thread

[edju1958]

I found the other starter for 10 series saws & put it on the 55.I pulled it a few times & had no spark,but it was skipping.I thought it was acting like a stuck pawl.Took the recoil back off & found a broken pawl.The dumb ass who had the saw pulled on it so hard that he broke the pawl,it's a fresh break.Lucky for me I had another flywheel with a good pawl & spring.I figured I'd do the right thing & take the flywheel off & clean everything.I took the points out & cleaned them up with emery cloth & found the lubricating felt was missing.I found a thinner Pioneer felt & shimmed it with a business card piece.Got it all together only to find it had no spark.I figured the condenser was bad,looked for another one & couldn't find one,so I got a chip & put it on & still no spark.Now I'm trying to figure out what the hell is going on.The only thing I could think of was a bad coil.Went & got another coil & put it on & had great spark.I had to go back in & see if the condenser was still good & it was.The saw has spark,but the carb needs to be rebuilt.It's missing a screw on the metering side cover & diaphragms are like cardboard.It's an SDC 49,never saw a carb like that - the adjusting needles are in odd places,I thought they were missing,Lol.Also missing the choke rod (got one here) & the snubber is broke (got one here).The oil cap I had is no good,but I may have another.If not I may have to buy one from Mark.I looked on feebay & I'm sure as hell not paying $15-$20 + shipping for one.The saw seems to have good compression.Oh yeah,the air filter had no flocking left on it.The fuel tank acts like it had some moisture in it,the fuel filter squished water out when I pulled it out to look at it,maybe just dry it out.I think the saw was run hard,but no scoring on the piston on the intake side.Surprisingly it has both bar plates.

 

[edju1958]

I gave Bob Johnson a call yesterday wishing him a happy birthday,his birthday is today,he's 83.When I called artound 1:30 p.m.he was napping.I guess old habits die hard,Lol.He was in good spirits & still pretty sharp in his wit.Always a pleasure talking with Bob,it brings back old memories of days on the phone ordering parts.

 

[MedicineMan]

This is something I've never seen.

 

[MedicineMan]

It's on a 6-10. My first right hand start. Piston is at TDC for photo. Couldn't find a witness mark

 

[Dream]

It's on a 6-10. My first right hand start. Piston is at TDC for photo. Couldn't find a witness mark

Never seen that either.
Ive got a 1-10 that is RHS. Never looked at it that closely.

 

[edju1958]

The PM 55 is coming along.Today I rebuilt the SDC49 & it wouldn't hold pressure.I've never had such a run of bad luck as I have on these damn Walbro carbs.I ended up putting an SDC65 in.The linkages are all hooked up as is the fuel line.All I need to do now is find the oil cap & put a new fuel filter in it & it should fire up.I think I have a new 20 in.bar & chain for it too.

 

[Maintenance Chief]

The PM 55 is coming along.Today I rebuilt the SDC49 & it wouldn't hold pressure.I've never had such a run of bad luck as I have on these damn Walbro carbs.I ended up putting an SDC65 in.The linkages are all hooked up as is the fuel line.All I need to do now is find the oil cap & put a new fuel filter in it & it should fire up.I think I have a new 20 in.bar & chain for it too.

Whay are you cleaning your carbs with Ed?

 

[heimannm]

While it is not immediately obvious, the RH start flywheels are slightly smaller in diameter than the LH start flywheels. There is enough adjustment in the coil that either flywheel can be used on the same block.





Both of the flywheels pictured above have the timing mark at 26 degrees BTDC.

LH Start



RH start - sorry about the staple, I didn't see it when I took the photo...



Some of the earlier RH start flywheels did not have any distinct timing mark, unless you count the trailing edge of that bell shaped protrusion.



Mark

 

[Vinnywv]

I have ben mia on here for awhile. My apologies. I have been working on another mac.project though with a machinist. Same guy that helped sleeve an 82cc mac. Anyway, i have a g70 and also a 5-10g. Both 10 series gear drives. I watched a video online and the young man stated he used an adapter and put a rim drive on his 5-10g. I got to thinking and planning and measuring. Talked to mitch and well a few weeks later i had 2 in my hand. Both hardened differently. The first one broke on the first run. The second one was not as brittle and so far works great. I ended up running a 28" bar and 3/8 full chisel chain. 8 tooth rim drive. I was cutting red oak and also ash. It worked as designed. I have one more test and then if anyone is interested id be happy to help get ya some. Ive mentioned on the other saw forum but ive been laxed on posting to both lately. Im not trying to make an early retirement either. My plan is to buy all.of them from him and get them to whomever would like one. Ive no idea how much he wants per drive either so whatever they cost me plus shipping will be the price. Heres the one that held up after nearly 2 tanks of fuel.

 

[Vinnywv]

That tillotson carb ended up with a bidding war. It started at .99 cents. When it hit 75 bucks i was pretty happy. I made money. I paid 60 bucks for it. When it ended i was astonished. Yes i was the seller. I could not believe that. Im not bragging by no means. Stunned. So was my wife when i showed her. Gotta love an auction.

 

[Squareground3691]

That tillotson carb ended up with a bidding war. It started at .99 cents. When it hit 75 bucks i was pretty happy. I made money. I paid 60 bucks for it. When it ended i was astonished. Yes i was the seller. I could not believe that. Im not bragging by no means. Stunned. So was my wife when i showed her. Gotta love an auction.

I think everyone was astonished . Lol

 

[edju1958]

Whay are you cleaning your carbs with Ed?

I use nothing on the inside unless they're varnished.The problems with the Walbo carbs is their damn check valves.I put the SDC65 on & it won't pull any fuel whatsoever.The saw will fire on a prime only.

 

[Maintenance Chief]

I use nothing on the inside unless they're varnished.The problems with the Walbo carbs is their damn check valves.I put the SDC65 on & it won't pull any fuel whatsoever.The saw will fire on a prime only.

It should fire on prime ,but the check valve is a PITA. Its symptoms are more it dies when throttled up though, it'll idle all day.
Try a little bit of mean green for varnish, I ve had pretty good luck with it.

 

[Squareground3691]

Got the PM850 reed muffler, with a fresh coat of high temp paint on the PM800, what a difference.

 

[MedicineMan]

Mark,
What was the practical purpose of having a timing mark? getting the points set exactly right? And where is the reference point on the crankcase?

 

[edju1958]

It should fire on prime ,but the check valve is a PITA. Its symptoms are more it dies when throttled up though, it'll idle all day.
Try a little bit of mean green for varnish, I ve had pretty good luck with it.

Thanks for the advice Ira.I pulled an SDC37 off a 1-10 I was working on a while back & notice a diamond shaped gasket that came off from under the carb.I don't remember there being a gasket on the 55.I'll pull the carb either tomorrow or Wed.to see if it's missing.This is what happens when I'm in a hurry,I make a rookie mistake..I fiddled with the SDC49 a bit & it still leaks down fast.If the SDC65 doesn't work then I'll put the SDC37 on.

 

[Maintenance Chief]

Thanks for the advice Ira.I pulled an SDC37 off a 1-10 I was working on a while back & notice a diamond shaped gasket that came off from under the carb.I don't remember there being a gasket on the 55.I'll pull the carb either tomorrow or Wed.to see if it's missing.This is what happens when I'm in a hurry,I make a rookie mistake..I fiddled with the SDC49 a bit & it still leaks down fast.If the SDC65 doesn't work then I'll put the SDC37 on.

All I know Ed is carburetor work takes me alot longer than it used to if I'm not wearing my 3xs readers! Lol

 

[Maintenance Chief]

Got the PM850 reed muffler, with a fresh coat of high temp paint on the PM800, what a difference. View attachment 364773

Looks good.

 

[heimannm]

The McCulloch convention for setting the points (timing) was to set the timing mark at a point on the coil and see when the points are open/closed. McCulloch also made some timing "tools" you could slip over the crankshaft when the flywheel was removed to make it easier to adjust the points and check the timing.



The timing mark on the flywheel would be pointing at the trailing edge of the outside leg where the timing tool points to the trailing edge of the middle leg when the points open.

With all that, I just set the point gap at 0.018-0.020" and leave it at that.

Mark

 

[MedicineMan]

The McCulloch convention for setting the points (timing) was to set the timing mark at a point on the coil and see when the points are open/closed. McCulloch also made some timing "tools" you could slip over the crankshaft when the flywheel was removed to make it easier to adjust the points and check the timing.

View attachment 364798

The timing mark on the flywheel would be pointing at the trailing edge of the outside leg where the timing tool points to the trailing edge of the middle leg when the points open.

With all that, I just set the point gap at 0.018-0.020" and leave it at that.

Mark

Thanks Mark. Good education. I've always just used 0.019 just in case I'm a little off. Has always worked fine. I know I'm being over curious but I wonder why they bothered putting before and after marks on my flywheel. There is enough slop in the flywheel keyway to rotate about 1/2 the distance to the adjacent mark. I was thinking that it might just be wear. There is actually more slop in the bolt holes in the coil but moving the coil to advance or retard the timing would negate the timing marks as the coil is the reference point.