MCCULLOCH The official McCulloch thread

[cinci5]

Just curious, I have a 10-10A and a 10-10S apart and the rods are different lengths. I thought the cranks were basically the same except for cam for points. Mikes says the strokes are the same 1.375" So my question is what is the real difference then besides bore and why are the rods different ?

 

[Steve]

The pin height may be different between the 54 and 57cc engine. I'd start by checking the pin to crown height and report back.


This is very interesting. I always assumed the rods had the same length!

 

[cinci5]

The pin height may be different between the 54 and 57cc engine. I'd start by checking the pin to crown height and report back.


This is very interesting. I always assumed the rods had the same length!

That's an issue I have as I tossed the 10-10A piston by accident so I can't measure it. I measured the cylinder depth and they are the same. Gotta be something I'm missing it's early.

 

[cinci5]

I tried to get it as close as possible. The top rod is from a 10-10A bottom assembly is a 10-10S. Maybe this can help distinguish it for someone, obviously not me.

 

[heimannm]

I have no idea if this is was McCulloch was doing with the 57cc saws, but this is interesting in any case.

Mark

 

[Steve]

I have no idea if this is was McCulloch was doing with the 57cc saws, but this is interesting in any case.

Mark

That guy has a great way of explaining theory in all of his videos.

 

[edju1958]

That guy has a great way of explaining theory in all of his videos.

It's all Greek to me,LOL.

 

[edju1958]

Well the 610 saga continues.I got the Timber Bear running & oiling just fine.I started it up today & the recoil rope didn't rertract.I had a helluva time pulling the recoil off the saw.It was like the pulley shaft had locked up with the pawls,or something similar.The pawls are fine.I found another recoil yesterday while looking for the oil pumps & put that on the saw & it works fine.The only thing I can think of is the original pulley was metal & I put a plastic pulley on when I repaired the original recoilI made sure that the pulley was the correct part # as was in the IPL.

I then moved on to the non-oiling 610.The oil line was intact in the tank.I drained out the oil & put some gas in the tank to try to dissolve any coating that may've been on the oil pick up.The pump pushed the gas out through the oil pad & onto the chain.So I dumped out the gas & put oil back in & it refused to oil.I had enough of playing with oil pumps,so I pulled that pump off & put a new pump on.It oils quite well now.But.....I took the saw out for a test cut & every time I'd put it to wood it would just bog down.I tried adjusting the carb & it made little difference.I ended up pulling the Zama carb off that I'd put on a couple weeks ago & did a pressure test on it.It holds pressure just fine,but when I went to bleed it down by pushing a toothpick on the metering diaphragm/lever it wouldn't release any pressure.I've never seen this before & I'm stumped.I'm putting a Walbro on in it's place.I know some guys swear by the Zama carbs,but they're a giant PITA to me.My line of thinking is this - why put a Japanese carb on a saw when we have a perfectly good carb that's made here in the USA?Even the Tilly HK carb is garbage IMO.It's the worst carb that Tilly ever made IMO.
Now everyone knows where my loyalties lie.Rant over.

 

[JKNW]

Playing with leftovers tonight. I got a box with an incomplete/disassembled 130 and 160S when I bought my Mini-Mac. Went ahead and went through what was in the box to see if it was worth saving after dinner. The 160 was rusted up tight, but this 130 spun free, checked for spark and it was there so I cobbled together enough of a power head that I could pull it and it fired right up on a snort of gas down the carb. Not sure it's gonna be worth the effort/$$$ to make complete but I almost feel obligated now.

 

[heimannm]

There is no such thing as a "parts saw"...only projects waiting for completion...

 

[bobdeaton@ hotmail.com]

Will an 850 run with 125 psi of compression ? I just rebuilt one , cleaned up cylinder and piston . New rings and light hone of cylinder. I can not get it to run on gas squirted in carb . I thought compression would come up with some run time but ? Are there oversized rings for the larger saws ? I am looking for some advice .

 

[heimannm]

125 PSI should run. As far as I know, there are no oversize rings for saws with a chrome bore; if the chrome is worn it's gone.

Someone dropped off this interesting specimen today. I don't think the 35 would be my first choice for a kart engine.





Mark

 

[edju1958]

And the 610 saga continues on.I put the Walbro carb on & it wouldn't start till I primed it.I tried adjusting the carb so it'd idle,but the carb I put on had a problem with the idle screw.I shut the saw off (rather it stalled out) & I heard something odd under the recoil.I pulled the recoil off to find the FW nut had loosened up.I thought it best to pull the fan housing off & the FW to have a look.Good thing I did because the FW key had sheared off.I was able to get the key out of the crankshaft,but I didn't like the way the slot in the FW looked.I had another FW from the parts 605,but the pawls had been taken off (not by me),so I transferred the pawls from the damaged FW to the 605 FW along with the FWkey.I noticed the FW nut was a different size.The FW nut on the 610 was 11/16 & the FW nut from the 60-5 was 5/8.Maybe someone used a clutch nut on the FW & that's why it loosened up?
I quit working outside early as it was getting chilly,but took the carb inside to see what was up with the idle adustment screw.It turned out that I had another Walbro carb to compare it to,although it was a bit different.Someone had the little throttle stop lever apart at one time & the little piece that the adjustment screw is supposed to butt up against was put on backwards..I had to bend that little piece so it didn't bind against the carb body.It works great now.I'll put the carb on tomorrow & hopefully that'll end this 610 saga.

 

[Bigmac]

I have no idea if this is was McCulloch was doing with the 57cc saws, but this is interesting in any case.

Mark

Love that guy too, but there are even more variables in a two stroke, long rods create less port duration as a function of length, same stoke, and same stroke, same piston, different rod increases case volume, by increasing deck height, that can also effect transfer height tuning.

 

[bobdeaton@ hotmail.com]

n

An 800 super, a 1010s, 2 promac 700s, 4 promac 1010s, 1 right hand start 1010, 2 or 3 1010a, and a half dozen various black top 1010 saws. My friend wanted the 800 and the 1010s. Both of them were super clean, but the 1010s needed work. The 700 he kept runs strong, but the one he gave me was beat...pretty suspicious lol. I cherrypicked a promac 1010 that looked like it hadnt been fooled with. Still had packing peanuts stuck in the bottom of it, so I think it was an ebay purchase the guy had not fooled with. I wanted one that had not been "fixed" before. Most of the saws were a nightmare really. They had the wrong carbs and all kind of problems. Finally getting some of the issues sorted out.

 

[heimannm]

Todays curious McCulloch...by Husqvarna.







I also managed to get a couple of signs to put out in the display area.



Mark

 

[edju1958]

I have the same sign hanging above my garage door.

Apparently the crank on the 510 has a problem.It wouldn't hold the replacement nut either.I ended up pulling the saw apart completely & I'm going to transfer everything onto an engine that came out of a Monkey Wards saw that I got last summer.The M.W.saw fired on a prime,but was "worked on" by an imbicil who thought he was clever.There was no kill switch,the screws on the switch plate were not OEM & he had wires wrapped around them possibly acting as lock washers,& the screws on the oil tank that hold the fan housing/recoiol on were replaced by unbelievably large bolts.I'm surprised the oil tank didn't leak.Regardless,the oil tank is useless.
The carb I thought I'd fixed gave me problems too,it wouldn't pull fuel.So,I'm going to use the carb that was on the M.W.

 

[cinci5]

Something on Market Place new for me never saw one. It says brand new in the case never gassed.

 

[edju1958]

I swapped everything over onto the MW engine only to find out that it has an air leak from a bad crank seal.Then I discovered that I've been ripped off once again.This time the prick(s) made off with at least 3 Poulan Pros & 2 of the recently acquired 610s.I'd have to say that they've made off with around 25 saws over the past 6 yrs.I keep my garage & my house locked up at all times when I'm not home & at night.The only thing I can think of is that a former tenant made a duplicate house key.If I ever catch him he'll be missing his nuts cuz I'm going to shoot 'em off.

 

[Al Smith]

Regarding the model 610 IMO the oil pump is the weak link .I've never had any luck attempting to repair one .They either just plain will not pump or leak into the crankcase which will really carbon them up .Other than that plus they are heavy for 60 cc's not a bad saw .It's pretty hard to kill one .Other than the 610 I've never owned or worked on the later variants like the Timber Bear ,650 etc. I own a 650 but that's the 87 cc geardrive made in the mid 60's .