McCulloch Chain Saws

[heimannm]

Two types are easily rebuildable, the ones with the brass insert, and the ones with the longer plastic insert. Grab them with a pair of pliers and give a twist, they will pull right out.

I will try to remember and take a couple of photo's tonight to illustrate, never seem to have any lack of caps needing service.

Hey, I am only using the language the way it was intended...if some have twisted or misused the meaning I cannot be held resposible. I for one will not be niggardly with my freedom of expression and proper use of words.

Mark

 

[promac850]

Two types are easily rebuildable, the ones with the brass insert, and the ones with the longer plastic insert. Grab them with a pair of pliers and give a twist, they will pull right out.

I will try to remember and take a couple of photo's tonight to illustrate, never seem to have any lack of caps needing service.

Hey, I am only using the language the way it was intended...if some have twisted or misused the meaning I cannot be held resposible. I for one will not be niggardly with my freedom of expression and proper use of words.

Mark

It's just a bird.

As for Macs, I plan on fixing the recoil spring and putting the saw back together, then trying again... tonight, that is. I look forward to your cap repair how to as I still haven't put a duckbill on the cap for the 850. It'll "pee" a little when it's tipped on its side...

 

[rwoods]

Problem Solved - PM805 is alive and well!!!!

You guys are brilliant, just keep up the banter. I swapped out fuel caps on the PM805 and she runs. Idles well and accelerates super fast. Thanks. Ron

 

[rwoods]

Actually, the duck bill valve should allow the tank to build up pressure but prevent a vacuum.

I am not suggesting that repairing or replacing yours will not cure the current issue.

On the older large frame McCulloch saws the same duckbill valve was used in the fuel caps for many saws, as well as in the McCulloch pressure pulse carburetors. Those valves all have 6 little "tits" on the bottom end that would, theoretically allow the valve to unseat if the pressure went up too much and vent the excess. There is somewhere a Service Bulletin describing cutting 3 of the 6 little tits off to reduce the "pop off" pressure in the pressure pulse carburetor.

For 10 Series saws the duckbill is held in position with a small spring, it is very possible that the spring is also calibrated to allow the tank to vent excess pressure and avoid the kind of issue ODW has been having. If the duck bill has turned to goo (whale snot according to one of our east coast guys) it can't vent no matter what and could certainly cause excess fuel pressure related problems.

I have discovered that the little red Homelite duck bill valve (sorry, I don't have the part number memorized) will serve as a drop in replacement for the orginal NLA Mcculloch duck bill in the fuel cap for those that can be disassembled and replaced. On a few where the spring was AWOL or badly damages, I have gotten by stacking 3 #0 o-rings over the nipple before installing the duck bill and it seems to work under normal conditions. Not sure what happens if it gets very hot and creates a lot of pressure in the tank.

Mark

Mark. I look forward to your followup post and the Homelite part number. A new cap is about $25.00. Last night I ordered $200+ in consumable parts for the 800s; it didn't occur to me that cap parts should be on the list. Ron

 

[rwoods]

McMaster Carr has 12-24 x 1" hex...
Stainless - 92314A296
Zinc - 93075A296

You taught me something. I was searching cap bolts and should have been searching machine screws. Thanks, Ron

 

[dieselsmoke]

You guys are brilliant, just keep up the banter. I swapped out fuel caps on the PM805 and she runs. Idles well and accelerates super fast. Thanks. Ron

Awesome!! Now if someone will lift the hex on Kyle and his 790....

 

[RandyMac]

Awesome!! Now if someone will lift the hex on Kyle and his 790....

I think the kid is missing something simple, Kyle needs to retrace his steps, starting with flywheel removal and run the ignition again.

 

[dieselsmoke]

I second that plan. Patience is a virtue....... lost in the make up of one Kyle, AKA shop monkey.

 

[Eccentric]

Homelite Duckbill Valve Part Number.

Mark. I look forward to your followup post and the Homelite part number. A new cap is about $25.00. Last night I ordered $200+ in consumable parts for the 800s; it didn't occur to me that cap parts should be on the list. Ron

Ask and ye shall receive my friend.

Homelite #69451. Available new from Oregon and Stens. Which 10-series caps are rebuildable (and which caps aren't)? "Nipples" and "tits" in the Mac thread.

 

[rwoods]

Ask and ye shall receive my friend.

Thanks. I just skimmed over it. I also found a source for new caps for under $10. Ron

 

[dce1843]

Thanks. I just skimmed over it. I also found a source for new caps for under $10. Ron

Where? I need one for my double eagle 80. It also leaks a bit when is tipped.

 

[rwoods]

Where? I need one for my double eagle 80. It also leaks a bit when is tipped.

Banta Saw - Small Engine Parts and Accessories DE80s are nice saws. Ron

PS You may just need a gasket for the leakage if it isn't the valve simply doing it's job.

 

[Toolslinger]

You taught me something. I was searching cap bolts and should have been searching machine screws. Thanks, Ron

No worries... I spend half my day in that catalog/website... Awfully nice when you can get same day delivery from them... Can't beat that from anyplace else... Grainger, and MSC are both next day for me, and I'm an impatient soul...

-Tim

 

[paccity]

Ron, oops I thought 850, oh well, nice saw anyway. your saw should run for a moment with a squirt, and WOT, even if the carb is buggered. A bright blue spark is good, so maybe a timing issue?

Kyle, my old 740 did not have a plastic sleeve under the points plate, the insulation had worn enough that it caused intermitent grounding. It would run fine one day, then no start the next. I had disconnected the stop switch wire to eliminate that possibility. Only then did I dig into the wiring from points to coil.

I have one tip for you guys with a sore arm, Go-Kart starter. I'll post a pic when I get home tonite. A quick spin with the spark plug out and grounded will show if spark is constant. With the plug in and a squirt of fuel I hit the start button and the saw WILL run. If it doesn't, then it's time to tear into it.

Nice gear-drives Frazier, Is the lower pic of your 1-6X?? Kinda looks familiar.

super 55 on bottom, 1-81 one top.

 

[a. palmer jr.]

I think the kid is missing something simple, Kyle needs to retrace his steps, starting with flywheel removal and run the ignition again.

Yeah, I think the ice was a little over the top. I got my big Echo started today in the heat with no trouble at all, not quite as big as his saw but big enough. He may need to check timing or something like that..

 

[dieselsmoke]

Fraz, now I see the bigger tank of the D-XX series, looks like a runner.
here's my 1-60 GD. It runs great, just a little hard on the hands, vibration.

 

[RandyMac]

Yeah, I think the ice was a little over the top. I got my big Echo started today in the heat with no trouble at all, not quite as big as his saw but big enough. He may need to check timing or something like that..

Maybe the ice was for his little fingers.

 

[heimannm]

Sorry guys, the grandchildren stopped by tonight and I was distracted from my appointed rounds. I will get to the cap photo's sooner rather than later. I will post some photo's of the Target progress tomorrow.

Mark

 

[rwoods]

Yeah, I think the ice was a little over the top. I got my big Echo started today in the heat with no trouble at all, not quite as big as his saw but big enough. He may need to check timing or something like that..

Kyle, with two cap culprit stories in a row I think I would check the cap. If the 250 cap doesn't interchange just loosen it a little. This is an easy item to eliminate from your potential culprits. Ron

 

[heimannm]

First off, the update on the 795/Target cut off saw - progress is slow but slow...I am rather taking my time and enjoying this one. The early 795 saw used thin rings (58353) but later saws, most 895's, and the 795L use a thick ring (62422). Fortunately I had a set of the thick rings in the attic so I went ahead and installed new rings and new seals. I don't really plan on using this one a lot (not a lot of concrete sawing in the forseeable future) so I expect the piston will be good enough. There were a few scuff marks as you might expect from a concrete saw, one on the intake side and one on the exhaust side in particular but nothing to be too concerned about. I did have to repair a broken wire from the points to the coil, but after one false start (the key fell out) I have the flywheel installed and a nice fat, blue spark.

Using Lee's advice I did install three long 10-24 studs in the intake to keep everything aligned as the tank went back on. I expect this one should be up and running by Saturday morning.

Mark