I can see the back of the cylinder, and it does look completely smooth. I'll try to tear it down soon though.
(I had a 90' oak tree crash through my shed last week so unfortunately my priorities are messed up right now.)
Cannot start MS260
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(I had a 90' oak tree crash through my shed last week so unfortunately my priorities are messed up right now.)
Well straight gas would be damage on both sides of the piston, what you are now describing could be a lean condition, we will see. Did you tamper with the carb adjustments? Did you cut with a dull chain and keep pushing through hardwood and get it real hot? Once a lean condition is suspected, you will have to do a vac and pressure test to assure it don't happen again, otherwise all the new parts are in jeopardy of failure.
Tamper with the carb, very possible. Dull chain? Never. And I never ever make the saws labor.
Well, if you turned the H jet clockwise away from the stop, that will do it! It should be resting on the stop . Go see if it is turned all the way counterclockwise till it hits the stop . And or then turn it clockwise slowly until it LIGHTLY bottoms out and measure how many turns out it was set at maybe 1 full turn, does it have the adjustments stamped on the side where the adjustment hole is it should say 1 turn or something like that if you are at like a half turn out that's way too lean. Wrong amount of adjustment will seize an engine up for sure.
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Could be it was tuned a tad lean, used with 50:1 mix and perhaps heated as well, throw in a slight air leak and the progressive thing starts making sense.
Its like when the clutch starts going in your truck- you do not really notice because you adjust to it slowly getting worse- someone else driving it will pick it up quick smart.
But if you have all those conditions, notice the saw getting more bothersome and do not fix it- well we get to the situation you have now.
Once again- you are not alone there- MANY a saw has died in very similar circumstances.
Its like when the clutch starts going in your truck- you do not really notice because you adjust to it slowly getting worse- someone else driving it will pick it up quick smart.
But if you have all those conditions, notice the saw getting more bothersome and do not fix it- well we get to the situation you have now.
Once again- you are not alone there- MANY a saw has died in very similar circumstances.
All I can add is... have your phone with you and take lots of pictures as you disassemble along with tabs you write on to attach to parts. A sharpie to mark parts that join to match going back together. Lots of small tubs, margarine containers you can put a label on it and put parts that go together inside.
Simple now to do but let the saw sit for a long time while life gets busy, makes it easier when time is had to reassemble. Make it easier for your first saw rebuild.
With the wealth of knowledge here you are going to have success.
Simple now to do but let the saw sit for a long time while life gets busy, makes it easier when time is had to reassemble. Make it easier for your first saw rebuild.
With the wealth of knowledge here you are going to have success.
To OP.
Clean the saw up spotless before you take it apart. Both clutch and recoil side.
You can use a piece of rope for a piston stop. Clutch is left hand thread, don't try to take it off wrong way or you can snap the crank. You'll need a puller to take the flywheel off the crank. Clean out both sides under the clutch and flywheel/crank. Do this before you remove the cylinder in case it needs crank seals.
This is a real old thread I did on a 036 that I got for free after it was straight gassed. I rebuilt with OEM parts and there is a lot of pictures. I had to reload all the pictures as the first ones got lost when the site here crashed, pictures pickup on 2nd page. The 036 is almost the same saw as a MS260, just a little bigger.
This will be what you will be in for as far as work, assuming you don't need to buy a cylinder or work on the crankshaft bearings.
Rebuild of straight gassed 036
Get it about this clean before you pull the cylinder, that's a 026.....
Clean the saw up spotless before you take it apart. Both clutch and recoil side.
You can use a piece of rope for a piston stop. Clutch is left hand thread, don't try to take it off wrong way or you can snap the crank. You'll need a puller to take the flywheel off the crank. Clean out both sides under the clutch and flywheel/crank. Do this before you remove the cylinder in case it needs crank seals.
This is a real old thread I did on a 036 that I got for free after it was straight gassed. I rebuilt with OEM parts and there is a lot of pictures. I had to reload all the pictures as the first ones got lost when the site here crashed, pictures pickup on 2nd page. The 036 is almost the same saw as a MS260, just a little bigger.
This will be what you will be in for as far as work, assuming you don't need to buy a cylinder or work on the crankshaft bearings.
Rebuild of straight gassed 036
Get it about this clean before you pull the cylinder, that's a 026.....
I was under the impression the saw only had seen a few hours use. So, taking the clutch and flywheel off would seem a useless endeavor. Unless I missed something. Which is probable.
Everyone is jumping ahead! I want to see the carnage.
Not to jump ship or anything, but can't you just hold it hanging by the flywheel and give the crank a tap to pull the flywheel? Or no? Just wondering.
absolutely, what I do every time
also I never use a piston stop, just leave the sparkplug in and zip the flywheel nut off with an impact driver, clutch could be done the same way also, with low compression I would certainly hold the flywheel with a rag during this process, coil off already
clutch off, then flywheel, need the flywheel on to get the clutch off without a piston stop
edit, realistically, you can just hold the saw by the top handle and whack the nut to knock the flywheel loose, or leave the saw loosely sitting on the bench, as long as the saw can move the weight of the flywheel will do the work for you
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to remove the entire top end to replace itNa- you gotta undo the nut first.
But why do we need to remove the flywheel again?
So you don't get dirt in the case when you pull the cylinder. Do you want to finish cleaning that filth up with the cylinder off? Also makes scraping the gasket surface clean a lot easier.Na- you gotta undo the nut first.
But why do we need to remove the flywheel again?
Since the saw had some sort of lean condition you want the clutch and flywheel off to give it a pressure test and be able to see the seals. If the seals fail you already have them exposed.
I ponyed up the $10 years ago and brought a real flywheel puller instead of using one of the various cave man methods, I don't regret it. Soft nylon rope works fine for a piston stop.
I do nice clean work on my saws........
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Each to their own and all- but I have done many top end renew replacements without ever removing a flywheel just because.
I do do a lot of solvent washing and compressed air blowing before cracking the joint- but have never had lumps of debris jump off the back of the flywheel and into an open case set just because it could.
Just in from doing that very procedure on a 281XP that just arrived- gummed up thin rings. Flywheel stayed on during entire procedure.
Just goes to show more than one way to skin a cat I guess.
I pressure test before pulling the lot down- then you know if the wheel has to come off or not.
Brass hammer and yeah! If you have a puller, even better.
Every saw doesn't have a nut with a skirt. So, you can't just use a deep socket. And, if you just screw the nut out even with the end you can make a miss hit and break the cup, or bugger the threads. Either is bad.
So, if you consistently do it that way buy a few skirted nuts in case.
So, if you consistently do it that way buy a few skirted nuts in case.
How I do it. I'll loosen the flywheel nut, take it off and then rethread it and whack the nut with a large brass hammer. That way you don't bugger the threads and the impact of the brass hammer blow will pop the flywheel loose. One or two whacks usually does it. In fact that is how I do it with all my small engines if I need to remove the flywheel.
Are all these your own saws, or pay for play?
I'd rather my saws get a bath if I'm going to spend the time fixing them. Saves me time having to fix them again sooner than later.
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Both- often I will pull a flywheel to get a good deep clean under and NOT remove the cylinder on old used saws that come to me that I intend on keeping for myself. I am talking that much gunk in and around the ignition starter side half that the coil is buried type filth.
Paid to repair saws are charged by the hour- eat your dinner off of clean is not required nor expected by the owner and most would be miffed to see a deep cleaning charge added to an invoice.
If it is agreed to prior- sure, if not they get what I deem to be safe, that might be solvent and compressed air- or high pressure waterblast to the areas to be worked on.
But like I said, each to their own and if you have the time and the tooling- pull whatever you deem necessary- its just in this particular case, at this stage of the game, an owner with this level of experience and lack of tooling- for an MS 260 and to inspect the internals of the engine enough to try and determine a cause- the flywheel can stay in place and negate any possible further mishaps as described elsewhere.
