Glad to hear you got the old gal up & running again.
Ed
McCulloch Chain Saws
- Thread starter Bruce Hopf
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Ed
Glad to hear you got the old gal up & running again.
Ed
My son & I took down a medium sized maple for our elderly farmer neighbors yesterday.I hate to say this,but my son used the Stihl MS310 to fell it.(My 7-10 is in need of a new chain,I've got 2 of them on the way now) I am happy to say that the majority of the tree was cut up with my Super 10-10.That saw kicks ass! We were all done with bucking,hauling branches away,& loading the trailer in just under 2 hrs.Everyone was happy - the elderly neighbors don't have to worry about the tree falling on their house anymore,& we got some nice fire wood.
Ed
Ed
My son & I took down a medium sized maple for our elderly farmer neighbors yesterday.I hate to say this,but my son used the Stihl MS310 to fell it.(My 7-10 is in need of a new chain,I've got 2 of them on the way now) I am happy to say that the majority of the tree was cut up with my Super 10-10.That saw kicks ass! We were all done with bucking,hauling branches away,& loading the trailer in just under 2 hrs.Everyone was happy - the elderly neighbors don't have to worry about the tree falling on their house anymore,& we got some nice fire wood.
Ed
Ed
Nice one Ed.
The saga of Kevin's 7-10 continues...
I tore it all down again this week, pressure test and vacuum test were good, I had already replaced the flywheel side anyway. There was still a little bubbling through the automatic oil pump so I looked into it and found a few problems.
The gasket was also bad so I replaced it, fixed the piston as well.
Just to be sure I was not chasing my tail I rechecked the compression, 130 is not the best I've seen but it certainly is enough to make it run strong.
Recheck the crankcase again, there is still a very slight leak down somewhere but not through the seals, crankcase seam, or compression release. The oiler stopped making bubbling noises so we made some progress there.
I even changed the condenser as Brian had suggested but the results are all the same; starts well, top end is strong, but it won't idle steadily and no amount of adjustment will make it right. I have tried 4 different carburetors, three SDC18's and one SDC3 thinking a smaller one might work better at idle but the behavior is always the same.
I also tried spraying some carb cleaner at the PTO side seal with it running, no affect whatsoever. I thought maybe the intake gaskets or insulator between the cylinder and the fuel tank so I sprayed a bit in there with it running as well and again no affect.
So - Kevin you were right thinking that something was amiss, but I am having a very difficult time finding it.
Anyone else out there have any suggestions, I am open.
Mark
I tore it all down again this week, pressure test and vacuum test were good, I had already replaced the flywheel side anyway. There was still a little bubbling through the automatic oil pump so I looked into it and found a few problems.
The gasket was also bad so I replaced it, fixed the piston as well.
Just to be sure I was not chasing my tail I rechecked the compression, 130 is not the best I've seen but it certainly is enough to make it run strong.
Recheck the crankcase again, there is still a very slight leak down somewhere but not through the seals, crankcase seam, or compression release. The oiler stopped making bubbling noises so we made some progress there.
I even changed the condenser as Brian had suggested but the results are all the same; starts well, top end is strong, but it won't idle steadily and no amount of adjustment will make it right. I have tried 4 different carburetors, three SDC18's and one SDC3 thinking a smaller one might work better at idle but the behavior is always the same.
I also tried spraying some carb cleaner at the PTO side seal with it running, no affect whatsoever. I thought maybe the intake gaskets or insulator between the cylinder and the fuel tank so I sprayed a bit in there with it running as well and again no affect.
So - Kevin you were right thinking that something was amiss, but I am having a very difficult time finding it.
Anyone else out there have any suggestions, I am open.
Mark
Could you possibly be fighting a weird timing issue at low RPM's? Try a different flywheel and/or coil and see what happens?
I'm wondering ignition issue of some sort too
Just for the heck of it, did you pressure check the fuel line to make sure there isn't a pin hole in it inside the tank? I guess you could accomplish that by filling the fuel tank to the top.
If it is a (weird timing thing) I would think its got to do with space or distances between pick or coil bcause it evens out with rpms , had coil that was loose on the rails on a 10-10 allowing it to side back and forth.
Your a knowledgeable guy with these McCulloch saws Mark I'd go with the "weird thing" going on.
Your a knowledgeable guy with these McCulloch saws Mark I'd go with the "weird thing" going on.
Is there a clutch and drum on the saw?
I've run it both ways, with and without the clutch installed and it does not seem to have any impact on the way the saw behaves.
Mark
Mark
Ive had this thought since this started but didnt want to sound silly. He replaced the piston with an NOS. Is it in there backwards? Would it even run that way? Im no expert but could the piston in backwards cause these symptoms? Just a thought....you did ask for suggestions.
Kevin - can you comment on the above?
Mark
Mark
The piston direction is to position the ring end gap(s) so they don't hook on the exhaust port or a transfer and break a ring. That could explain the low compression or it could just mean the rings aren't seated yet.
Kind of a long shot and I bet you have changed the plug but I have seen them not fire consistently or plug wire arcing off somewhere. I think you have more than ruled out a carb issue.
Maybe perform an exorcism.
Brian
Maybe perform an exorcism.
Brian
I like the exorcism idea,maybe I'll perform one on my 7-10 & see if I get better results.Lol
Ed
Ed
I have tried to different plugs, same results. The piston skirts are also different, they won't cover the intake port if they're backwards
Mark
Mark
Mark I have seen you set up with a drill turning the flywheel and using a timing light to check timing. Wonder if you put it in this setup and watch closely for maybe a misfire. I am just digging deep. This is a very strange problem and I feel you have ruled out fuel issues, crank leak has been mostly ruled out though you said a very small leak. It seams like it has to be something ignition related. I had a PM6 once that would run wide open but would not idle and it turned out that the points were not making good contact at low RPM. That for some reason sticks in my head. I used a volt meter set in low OHMs and the coil disconnected. Slowly rotated the crank and you could see the points close and then kind of fluctuate before they opened, kind of like a dirty potentiometer. I had the points in wrong and it would not let the points move freely and completely close. They did not have the pressure to firmly close and did not make good contact. A long shot but just an idea to try.
Brian
Brian
Here is the kit I used to rethread the sparkplug for Ron's PM800 just so people know this exist. It is quite pricey but the best I have found. Time Sert.
The silver inserts are for taper seat plugs the coper inserts are for regular plugs.
Brian
The silver inserts are for taper seat plugs the coper inserts are for regular plugs.
Brian
Spent all day cutting today started the 1st 7-10 at 8am and here's a short little vid of a few play cookies of the first tree for the day
Run three macs all day and none missed a beat. I remembered to grab a few pictures today not very well thought about but any way..
That tree in backround got the chop it was just under 30 inches at the bottom.
That macro above is next hopefully it has like 5 big 20 odd inch trunks and the main one before the split is massive for me and my little 24inch bar.
That's around 80 years old and the others are even bigger lol they grow fast here and they are everywhere these and big pines and blugum trees are our horizon.
so far we've (3 of us) cut 16 trees out of here probably 20 inch average some way bigger I've cut the majority and has been a nice learning experience.
An old guy who was working on the farm had a real treat seeing all these old macs from 40 years ago. When he was in his 20s cutting firewood he ran them he hadn't seen them for a long long time and also thinks he has some bits n bob's for them in a box somewhere so was cool having a yack about them. He didn't realise people still ran these things especially not young blokes
He was also in amazement at me using an old steel wedge from donkey's years ago too.
Run three macs all day and none missed a beat. I remembered to grab a few pictures today not very well thought about but any way..
That tree in backround got the chop it was just under 30 inches at the bottom.
That macro above is next hopefully it has like 5 big 20 odd inch trunks and the main one before the split is massive for me and my little 24inch bar.That's around 80 years old and the others are even bigger lol they grow fast here and they are everywhere these and big pines and blugum trees are our horizon. so far we've (3 of us) cut 16 trees out of here probably 20 inch average some way bigger I've cut the majority and has been a nice learning experience. An old guy who was working on the farm had a real treat seeing all these old macs from 40 years ago. When he was in his 20s cutting firewood he ran them he hadn't seen them for a long long time and also thinks he has some bits n bob's for them in a box somewhere so was cool having a yack about them. He didn't realise people still ran these things especially not young blokes
He was also in amazement at me using an old steel wedge from donkey's years ago too.
