Ouch! Granny used to cut a switch off the live oak tree in the backyard and would get me on the backs of my calves. I wince just thinking about it!
Stihl 260MS Pro find
- Thread starter TrekJeff
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Ouch! Granny used to cut a switch off the live oak tree in the backyard and would get me on the backs of my calves. I wince just thinking about it!
So go in from the exhaust side, lots of oil and a flat hand? Then what about the impression on the cylinder wall, straight down with Mad Professor's method?
Like Brad said if that dent is bulged out it needs to be relieved back with the radius of the cylinder. If that takes out/goes through the nikasil at that spot add a small chamfer so you won't catch a ring or have some liner flake off.
The deformation in the port itself does not matter. Only the surface of the cylinder wall is critical. There can be NO high spots.
I was very conservative with the sanding. There's no lip or high spot that I could feel. Would smoking the old piston and cycling the crank do anything to show what I can't feel? If be looking for a line in the smoke residue.
Khntr85
Addicted to ArboristSite
My first rebuild ever had a flat head screw driver indention on the exghust port from the owner "working" on it....I was able to get the bad spot out...I used the saw quite a bit....I took the muffler off a few times to make sure there was no damage, and it was fine.....just actually sold the saw last week...
Here are some pics
Here are some pics
Crank is smooth as you could ever hope for. I'm ordering the new piston and rings today, hopefully I can have her back in the woods this next week. There's a lot of work I want to get done before the spring time growth takes place. Cutting all the mature aspen off at 4' high to promote new lower growth and get more sun...This project is all deer bedding area I'm focused on improving. Timber will just lay where I drop it to promote Morel mushrooms down the road, serve as drumming logs for grouse. I had been working on it with my Jonsered 630Super, but I ran old gas in that and it's on a shelf now waiting for a rebuild too.
BLS....I just watched a bunch of your videos....Nice collection of saws and the work you've done on them, before and after sounds great!
drf255
BAD CAD
Gasket should be the same. Most 44.7 260's have a squish around .017 without a gasket. You'll need sealant and to use good oil at that squish. The saw will run better though.
You can use acid to help you clean up that cylinder as well. Just not near that nic in the exhaust roof. I apply acid with Q-tip, keep wiping out, and sand in between acid application to allow acid contact to fresh aluminum. Then I need to sand very little. You just need to be careful near the squishband and ports. Also, you've got to take notice for any spot that keeps fizzing when it looks like there isn't much transfer. That can be a pin hole in the plating and the acid could undermine it.
Wash with soap and water after the acid. Soap is alkaline and should neutralize any acid.
That exhaust roof dent. Get a diamond coated ball for your dremel and slowly going that lip down. It's ok if you go a bit deeper than flush with the wall. Make sure you chamfer all the edges and then hand sand afterward.
You're lucky you got a 44.7mm, they are pretty rare. Most 260's I've seen are 44mm.
Because 44.7 are so rare, there's a glut of OEM NOS 44.7 pistons on eBay for very cheap. An OEM 44mm piston is over $50. A 44.7 can be had for $15 with rings delivered to your door.
You can use acid to help you clean up that cylinder as well. Just not near that nic in the exhaust roof. I apply acid with Q-tip, keep wiping out, and sand in between acid application to allow acid contact to fresh aluminum. Then I need to sand very little. You just need to be careful near the squishband and ports. Also, you've got to take notice for any spot that keeps fizzing when it looks like there isn't much transfer. That can be a pin hole in the plating and the acid could undermine it.
Wash with soap and water after the acid. Soap is alkaline and should neutralize any acid.
That exhaust roof dent. Get a diamond coated ball for your dremel and slowly going that lip down. It's ok if you go a bit deeper than flush with the wall. Make sure you chamfer all the edges and then hand sand afterward.
You're lucky you got a 44.7mm, they are pretty rare. Most 260's I've seen are 44mm.
Because 44.7 are so rare, there's a glut of OEM NOS 44.7 pistons on eBay for very cheap. An OEM 44mm piston is over $50. A 44.7 can be had for $15 with rings delivered to your door.
New piston kit from Meteor and gasket are at the house, delivered today...love USPS tracking service. The mightyvac should be there tomorrow so I can run the vac pressure test. Hope she can be working this weekend.
Thanks for the info about the squish. I was actually going to check that using the solder/grease method. The reading I've been doing shows that a carb adjustment would be needed and something about "4 cycling" and a muffler modification drilling two more holes...not really clear on all of that. I'll do more reading and see if I can't figure things out. I'm hoping to get the basics down on this saw, my next project will be the old 630 JRed.
Had some time to put things together. Pressure/vac test, Good, held pressure after sitting for 5 minutes. I did this before the new piston went in, just wanted to make sure the case itself was good and sealed. Then in my rush to get things put back together, while tapping in the new piston with the rings compressed, the end of the top ring came free from the ring compressor, placing itself out of the grove, before I realized what happened and gave it another "tap" with the mallet resistance was noted. I took off the ring compressor and saw the end if the ring pinched between the cylinder and piston. Backed everything out slow and 1/4" of that ring just fell off, it cracked. So live and learn, if there's pressure and it requires more UMPH, then stop, back off and observe. Ordering new rings today.
OK got everything put back together. But she'll fire with full choke the nothing after. Fresh gas, new plug. Could the clearance between the ignition and flywheel (or what ever is called) be off? The distance I found for my other saw is .30mm. Is that in the same ballpark as the Stihl?
drf255
BAD CAD
I use a business card to set the distance between the coil and flywheel. A bit tighter will increase your ignition advance, looser will retard.
All bets are off on a restoration that wasn't running. Sounds fuel related to me. Check the fuel line and filter, impulse line and carb.
@pioneerguy600 taught me a quick trick to check the impulse line on an assembled saw. Pull the carb and cover the outlet with a small dab of grease. Pull the saw over. If the blob didn't move at all, something's wrong.
Chinese H adjustable carbs work great and are cheap. Contact @Definitive Dave .
All bets are off on a restoration that wasn't running. Sounds fuel related to me. Check the fuel line and filter, impulse line and carb.
@pioneerguy600 taught me a quick trick to check the impulse line on an assembled saw. Pull the carb and cover the outlet with a small dab of grease. Pull the saw over. If the blob didn't move at all, something's wrong.
Chinese H adjustable carbs work great and are cheap. Contact @Definitive Dave .
Do you know the compression for this new frankensaw? A new Meteor piston in an OEM cylinder if I read this thread correctly, what was the piston to cylinder clearance? I have seen a 44mm piston come in a box marked 44.7, likely a one time return from someone but the box was completely undamaged.
drf255
BAD CAD
Excellent point Jerry.
He snapped a ring on assembly, I doubt the mismatch could be that great.
If it runs choked but not on fast idle, I think it's lacking fuel.
He snapped a ring on assembly, I doubt the mismatch could be that great.
If it runs choked but not on fast idle, I think it's lacking fuel.
Maybe I missed the running part. The way I read the last post was that it would hit but not start or run at all. If its just hitting sporadically and only when cold then it may be fuel related, it could even be flooding or as my first thought was low compression. We need more details from the OP, I like to get a better picture of all the support system to make an educated guess at what is going on with this saw.
I build so many box of parts saws that I see many with multiple problems.
I never thought of checking the clearance from piston to cylinder, but I did mic the new piston and sized it up with the one being replaced, that checked out.
Rings are camber. Compression is just shy of 170.
Pioneer, you are correct, it won't idle, it will just fire once then nothing. I mixed the gas 30:1, could that be to much oil? I wanted it rich for break in.
