Discussion in 'Chainsaw' started by Paul Bunions, Jan 4, 2019.
I just choke it, and pull the starter. The rest of it is Greek, and English.
Overheating a clutch drum can produce some distortion. A common way to overheat it is to stall the chain in the cut and keep the power on hoping to get it unstuck and another way is to consistently lug the engine down to the point where the clutch starts to slip, usually by putting too much pressure on the bar to try and make a dull chain cut. If the chain is stopped and the throttle is held open, all the power the engine is making shows up as heat in the clutch. Melted clutch bearing cages and melted side cover plastic is a common result as well as weakened clutch springs that produce a lowered rpm engagement.
I have gotten stuck a number of times. I wonder if that was the beginning of this mess. Now that I have this information, I can avoid this problem in the future. Thanks.
More bad news. I got the new parts, and I started installing them. Then I found out the piston was stuck.
When I Googled for help with this thing, I saw that people suggested putting a piece of rope in the chamber to keep the piston from moving while removing the clutch. Unfortunately, the 3/8" nylon rope I used appears to be partially sheared between the piston and exhaust opening, and the piston will not budge.
I made a dowel and inserted it through the spark plug hole, and I banged on the end of it to knock the piston back down, but nothing happened.
Pull the muffler and see if you can pull apart some of the cord with needle nose pliers.
Otherwise, you might have to pull the cylinder.
The rope method claims another victim!!!!!!
So this is common? If it's common, there must be a known counter move.
Take a few pics and put them up, firstly.
It's only common if you aren't paying attention and/or are (un)lucky enough to get the rope caught in the exhaust port! Normally you advance the piston to cover the port BEFORE you start stuffing in the rope. Stihl also makes a plastic piston stop for this same purpose. However, it likes to slip out of position if you are not careful.
Um...I put the rope in through the exhaust port. If I manage to get the cylinder off, can I count on having to replace the gasket? That would mean ordering one and waiting a week.
Take off the pull starter, and try turning the flywheel by hand.
Put up some pics.
Yeah, that was wrong. Can't believe everything you read on the Internet for free (including chainsaw forums). Should feed it through the spark plug hole after raising the piston past the exhaust port opening (like @SteveSr noted).
Might not have to. Depends on the condition. Cheap part to replace if you are opening things up.
Although I have a non-rope piston block that I now use, for years I used this one:
The knot that goes inside the spark plug opening is on the left, just beyond the threads. That's heavy-duty nylon pull cord that has never broken apart. One of thee days I may replace this cord with the next size down because the piston will sometimes flatten the knot and that makes it a little tough to pull out. One thing it has never done is crack the piston or the rod.
I got the saw put back together. I had so much trouble with the little brake band, I wonder if I would be better off leaving it off the saw. I think it may actually be a little short, causing it to apply friction when the saw is cutting. I suppose I could re-bend it to add a small amount of slack.
Today, I started the saw, and it ran great. Problem: it ran too well. It idled so fast the chain would not stop moving.
I looked up information on the web, and I decided the solution was to adjust the carb screws (L & H still have factory caps on them; idle speed screw is not covered). I am using the new carb I bought. When I took the saw to be repaired, the mechanic stuck me with an old carb and kept my new one, which was probably full of gum anyway.
Now I have a saw that will not start. Clearly, I adjusted the screws wrong.
I got some bad information. Someone said to turn all 3 screws all the way in, and to start from there. The idle speed screw on this saw does not work that way. It has a conical end to it, and the cone contacts a little arm that controls the throttle. The farther in the cone goes, the more the throttle opens. When you turn the screw in all the way, you open the throttle to its maximum resting opening, and you also go way past the conical tip, so in order to get back to the starting point, you have to back the screw out.
When the saw was running away, I had the screw turned in so far, the little throttle arm was resting on the threads, not the conical tip. I didn't know this. I thought the answer was to turn the screw in farther, which, of course, was the wrong direction.
Where should I start with these screws? My right hand is now blistered, so I am hoping to get the saw working without pulling the cord another 200 times. Should have worn a glove.
The throttle just BARELY opens on this carb, with the speed screw adjusted to maximum. I looked at the old carb the mechanic left in the saw when I took it back, and I would say it opens a little over a millimeter, which is considerably more.
Separate names with a comma.