McCulloch Chain Saws
- Thread starter Bruce Hopf
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ML12
ArboristSite Guru
I tore down my SP81 last night to find that there is some light scoring on the piston on each side of the exhaust. Seems odd, usually I see scoring right down the middle of the exhaust port. What could cause this?
I also ordered a piston from chainsawr, it says it fits a SP81, and I didn't find any letter stamped on the top of the jug near the spark plug so I am safe to assume its a "B" cylinder. Does anyone have experience with these aftermarket pistons?
I also ordered a piston from chainsawr, it says it fits a SP81, and I didn't find any letter stamped on the top of the jug near the spark plug so I am safe to assume its a "B" cylinder. Does anyone have experience with these aftermarket pistons?
Walter Glover
ArboristSite Guru
Scoring? Most likely carbon trapped in rings then embedded in piston. Get her fixed eh !
Don't get over excited about a little scoring, they will still run well as long as you can make 125 + PSI compression.
Mark
Mark
I have a 10-10 that was scorn on either end of the exhaust port like that. I cleaned it up used another piston, as I had one laying around. If I had not had another piston just laying around I would have cleaned up that piston and used it. It runs good. I use it to cut with all the time. A little scoring is not the end of the world. Big compression is nice but not essential. Like Mark said a saw with 125psi of compression will do alright. Most times after a rebuild like that I will not even check the compression. If it runs good and cuts good I don't care what it's compression is. To me checking the compression is more of a diagnostic thing to see if something is wrong. If it runs good then use it, if it don't then worry about it at that point.
Brian
Brian
Simply use fed ex, ups or usps. It is all charged by weight and destination. Box up the saw with the bar removed, gas drained and oil emptied. Double bag the saw in good plastic bags to keep odor in and any oil drippage. Wrap the bar in cardboard to prevent it from moving in the box and tape to the side of the box if possible. Use a box large enough to allow for packing material to surround the saw and prevent shipping damage. Once the box is sealed with enough tape to insure closure, you may call ups for a pick-up or take to the post office for shipping. You prepay the shipping and back charge the buyer. You can find shipping rates online to most places through the post office and ups or fed ex. Just weight the entire box after it is sealed for a final weight. keep me posted concerning the pm700
ML12
ArboristSite Guru
It definitely has strong compression, and I've had it running briefly so I know that it will run.
I will finish the tear down tonight and take some pictures to post.
Thanks for the advice guys!
Mr. Piste
ArboristSite Lurker
What is the best way to remove the wrist pin from a 380 piston? I put a little WD40 on the ends of the pin and needle cages and let it soak for about 12 hours, but I still can't get any movement. Do you remove the pin from the closed side, or the open side?
Going back to the FW side seals. I was looking at the two 5-10A IPL's I have.
The 1966 IPL (65663) shows a FW side seal PN 65746
The 1971 IPL (85763) shows a FW side seal PN 61618
The 1971 IPL also states in the notes on page 5,
That would mean to me that the 65746 PN was changed to 61618.
The 5-10A is the next saw up as the seals need changing.
Dawnsman
ArboristSite Guru
Guys I've been gone a while seems like you can't tell a judge what is on your mind but any way I'm looking for a fuel tank for a super 250 if anyone has one please let me know
Sent from my SCH-I545 using Tapatalk
Sent from my SCH-I545 using Tapatalk
I just pulled the seal in the 5-10A and it is stamped 61618-1
Walter Glover
ArboristSite Guru
I cannot seem to 'tune' my CP70
It warbles in the cut and wants to die when you cut the throttle. Need that carb kit bad.
Edit
Cleaned carb again except for Welch plugs, seems to run crisp at idle with good acceleration to top, good fourstroking sound but if held there for say 5 seconds it leans out revving up til it dies out, off the throttle and it recovers and can repeat or let it idle. Soooooooo now it appears to be fuel supply issues?
How are these 10 series saws vented? Can those huge filters restrict the flow of fuel to this degree?
Hmmmmm
It warbles in the cut and wants to die when you cut the throttle. Need that carb kit bad.
Edit
Cleaned carb again except for Welch plugs, seems to run crisp at idle with good acceleration to top, good fourstroking sound but if held there for say 5 seconds it leans out revving up til it dies out, off the throttle and it recovers and can repeat or let it idle. Soooooooo now it appears to be fuel supply issues?
How are these 10 series saws vented? Can those huge filters restrict the flow of fuel to this degree?
Hmmmmm
It has been over a year since I have put a Mac in wood. I pulled down the PM570 and rebuilt the carb. I hadn't done that in the 3 years since I'd picked it up. It responded well.
I noodled down some rounds after I dialed it in. Pulled like a train. I'd forgotten how strong these were.
Some of the Douglas I was processing was ripe with goodness. It will burn very hot when the time comes.
I noodled down some rounds after I dialed it in. Pulled like a train. I'd forgotten how strong these were.
Some of the Douglas I was processing was ripe with goodness. It will burn very hot when the time comes.
There's a duckbill valve inside the fuel cap.
The fuel issue almost sounds like a carb governor issue. Not sure if you have one on that saw.
Mac&Homelite
Addicted to ArboristSite
By the way, do the 10-series use the poulan or homelite duckbill valves?
Got back in the saddle today after being summoned to the woodlot to cut some "big" stuff. The big stuff turned out to be two 12 to 14' maple logs about 5' across and 30" deep (it was a split trunk tree), several 30" maple logs and several 3 to 4' oak stubs about 6' long. Brian met me there. Unfortunately while waiting on MAC parts to arrive this summer, he went over to the dark side and built a chinacom 660. If he doesn't get his 125 together soon, we may need to schedule an intervention.
I brought a Sp125C with a 33/34" ten series .404 bar and Brian brought his chinacom with a 28" 3/8" bar and a Mac 600 series as a backup. I shot a video of him running the chinacom but I can't remember how to download from my phone. I thought it ran well. Of course the 125 just snacked on the maple. We took care of the pile. Not sure how much fuel Brian burned but I went through three tanks on the 125.
Only pictures that I took worth posting:
Posing at the pile next door before we started; my before picture of our log pile didn't take for some reason.
After photo - most pieces skidded away, some pushed to the side; all that sawdust was ours.
Ron
I brought a Sp125C with a 33/34" ten series .404 bar and Brian brought his chinacom with a 28" 3/8" bar and a Mac 600 series as a backup. I shot a video of him running the chinacom but I can't remember how to download from my phone. I thought it ran well. Of course the 125 just snacked on the maple. We took care of the pile. Not sure how much fuel Brian burned but I went through three tanks on the 125.
Only pictures that I took worth posting:
Posing at the pile next door before we started; my before picture of our log pile didn't take for some reason.
After photo - most pieces skidded away, some pushed to the side; all that sawdust was ours.
Ron
Now for some serious Mac discussion. Brian broke the sad news to me today that my 101B 125 encountered a major hiccup shortly after he cranked it this week. I posted a video of it running a few weeks ago. Being the careful and meticulous person that he is, Brian wanted to change out the NOS seals we used in the rebuild for some fresher (and doubled lipped) seals. He did this, reassembled the saw and cranked it in preparation of tuning it. It immediately when down. He disassembled it to find that the wrist pin had walked to the closed side, the wrist pin needle bearings were split out and two eaten between the piston and the cylinder wall. We are a little baffled as to why a pressed in wrist pin would move. I told him that I would bet someone here has had it happen and would know why. Would that have been a good bet? If it helps some may recall that the reason I had the saw rebuilt in the first place is the rod would bind when the saw was turned on its clutch side. Following advice here, I purchased all new bearings and had the rod checked for straightness. The rod was a little blue on the wrist pin end but the consensus before was it was okay. Unknown to me until recently, Brain also had a machine shop check the rod before he rebuilt the saw.
Thanks in advance for your sage advice.
Ron
Thanks in advance for your sage advice.
Ron
I've used both but there are a few different style caps.
Mark Heimann did a great write up on them some time ago. Not sure where it is. Maybe someone saved a link?
Yikes Ron! Sorry that happened.
A few pictures of Ron cutting with his SP125c. Had it buried up all the way most of the day and that thing just kept on going like a champ. Love the sound of the SP125c. It just sounds like it could saw all day long at that speed and never breath hard.
This is why Ron's back is probably hurting right now (I know mine is, right between the shoulders) and will be hurting bad tomorrow. I was worried about him in the heat today but this time he took my advice and cooled off a little. He was getting way too hot and he don't realize it when he does. But the SP125c was really going strong and Ron had it going for a lot of hours today.
Brian
This is why Ron's back is probably hurting right now (I know mine is, right between the shoulders) and will be hurting bad tomorrow. I was worried about him in the heat today but this time he took my advice and cooled off a little. He was getting way too hot and he don't realize it when he does. But the SP125c was really going strong and Ron had it going for a lot of hours today.
Brian
