spudulike

And don't we all know it:001_rolleyes: Seen sprockets spinning on the spot, disappearing down the drive at high speed, shoes flying off for 30 yards:blushing: Never again!!!

Long time no hear Wes, those 181/281s are a bit of a pig to pull over as standard let alone with extra compression, they do go well though. Done any porting on it?

Mmm you would be surprised:001_rolleyes:

Well you can try turning it anti clockwise but it will never come off, the left hand thread is there to stop the clutch undoing as the machine cuts......think about it please:001_rolleyes: Maybe that is why it won't come off!!!!

A bit of heat can work but in the past I have ground the socket end so it is flat and makes the most contact with the clutch hex boss as some have rounded ends on them that don't grip the hex immediately. You then just use a decent stop, put a decent tommy bar on the socket, stick your foot in the handle, hold down the top handle and pull the bar upwards with much force while making sure it doesn't slide off! I think if that central boss goes, you are looking at either grinding it off or creating a special tool to locate on the clutch - old sockets can be ground down - I use this on Husqvarnas. A piece of weighty bar and two dowels brazed in it and engaged in the clutch may get you out of the mire but just contemplating the worst case scenario If you use heat, apply it to the boss and get some oil on the middle but be prepared to chuck a damp cloth over the fire:blushing: I hate to say it but the Stihl ones with the big or small hex boss are the easiest to remove! You could try and air chuck or take it to the local garage but ensure they know it is a left hand thread - clockwise to get it off!!

Probably the metering diaphragm has gone hard or the metering arm is too low:thumbup: Check the fuel line is OK as well!

Yes, fortunately the crankcase survived as did the crank shaft (measured up OK) a lucky one but was still pretty costly on new parts! Your 346XP cylinder is almost ported BTW, just the upper transfers to do then bevelling the modified port edges. New fuel line fitted as the original one snapped when the carb was removed! Should be good once done:thumbup:

Exactly what I said!

You can use hand sanitizer - the ones that make your hands cold, many solvents don't work, the ones that do tend to be oil based. I have 5 litres of printing ink solvent that works pretty well!

Had a Stihl MS441 in at the weekend, the saw was locked solid, the owner thought seized but my thoughts were it would be unusual as seized saws generally free up once cool. Pulling on the starter wouldn't shift it so the next step was to strip off the cases to see what gave, the clutch cover came off and inside, a birds nest of noodles and the picture below. It looks like the clutch and clutch drum had seen better days as the mating surfaces were worn significantly to the point that the clutch burst the drum and impacted the brake band totally destroying it. I will fit a new clutch, drum, needle bearing, brake band and a new oiler as the arm was also buggered. The oiler looks OK despite being impacted and the top surface being badly abraded. It should be up and running in due course:thumbup:

The Stihl stuff always has part numbers "Stihl" ir "Mahle" on them, the pistons also have distinctive stamps on the crown and usually a crosshatch pattern on the inside crown of the piston. If these are not present then perhaps someone has ground them flat...........or it is aftermarket! The shortness of the piston is probably down to the stroke of the engine and the inlet port timing which is dictated by the skirt length! Short stroke pistons tend to be shorter.

Nice bit of furniture, just watched the programme, nice job:thumbup:

Yup, a bad bearing can knock the sprocket out so if there is play with a new bearing, change the sprocket as well.

Yes, usual issue is the flange wears till it has gone, the pinion rubs on the outer seal until it leaks or the oiler misses the drum. Fit a new one and replace the seal if worn and leaking!

worth a go if you can do it yourself, make sure you seal the bottom joint well and also check the reason for failure with a leak down test. If you have no facillity to do this then fit new seals, use a quality gasket sealent and check the manifold and impulse line has no splits etc.

nope, it is just that the oiler pinion has an internal flange that can wear down in time. Seen it s few times now

Brick cleaner is acidic and works so does caustic soda. As long as the aluminium fizzes, it will do the job. Repetative rubbing of a damaged area will cause minute cavities that will lower compression and will take forever to bed in so get rid of the worst with the chemical first and then use 120 -140 followed by 400 grit to finish it - rub around the bore and not up and down. You shouldn't be able to feel any damage once the job is finished. MS200 - I am waiting for stuff for over a year from some:001_rolleyes:

The piston is shagged but the rings are still loose so not too bad but use a Meteor replacement. Clean the aluminium off the bore fully until it has all gone, best use chemical and then rub off the oxide residue until it is clean and then hone with wet and dry of a small bore hone but don't go mad! Should make 170psi plus when done! Set the H screw a tad rich for the first few tank fulls

Check the Impulse is clear, the fuel line isn't split, the fuel filter is clean, the tank breather is clear, the manifold isn't split, the carb metering height is correct, the flywheel to coil gap is OK and then check the low speed section of the carb is clean. These issues tend to be fuel related!

Thats what we hang around for:thumbup: Let us know how it works out.

Make sure the clutch bearing is ok, if it has gone, it may be causing friction on the crank stopping it idling properly! Other than that, check the fuel system and carb settings, just mention the clutch bearing as that is the usual issue with this saw!

It is always better to try to clean up the original cylinder than fitting an aftermarket one.. Meteor are the best pistons after the OEM part with Episan also being good and the likes of Golf and others coming after that. I have used Meteor pistons in many saws in standard and tuned saws with no issues.

The issue won't be with the quality of the piston but with how well your friend cleans the cylinder and if he sorts out the cause of the seize correctly and tunes the carb to the correct revs for the saw. Largest saw - done a few 395XPs and many MS660s all in profesional daily use, the longest in use must be 3-4 years+

Another suggestion is to fit a much longer bolt and put a nut on the other side of the alloy casting to hold it in place!

Use a helicoil or insert if the hole is too large for the helicoil.