spudulike

We had this discussion a while ago, firstly, it is NIKASIL and the emery will have similar abrasives to a hone - Silicon Carbide/Carborundum and you simply do the work and then clean thoroughly with solvent and compressor. Anyone who says this can't be done - go talk to the guys I have rebuilt seized saws for still using them years afterwards! I have used emery paper on localised damage and to smooth bevels, the hone will give a nice finished surface but don't go too mad, an engine doesn't take a view to how it looks but does note how well mating surfaces join together.

I rarely sell machines I have refurbished but have been working on a 2009 MS460 that has been stood up for the last five years after being lean seized. You can see the original piston in one of the photos! I have done some porting on this saw, the muffler hasn't been modded although it could be and the ignition has been advanced a little. It now has a Meteor piston in it, the cylinder is fine and compression is very healthy. The saw has been pressure and vacuum checked, the carb has been stripped and checked and it is very clean. It won't be going at a bargain price as it now owes me a bit but if you are looking at a saw that will pull like a train and keep you in business then PM me for a price.

Just caught up, you should be looking at the most powerful option out of the box and then port, muffler mod and use a head with extra long thick lines. I say this as you will need to keep the thing bang on the powerband and cut as much as you possibly can - perhaps make a special head with wire cable lines so you are less likely to loose one and cock up your chances. Failing that - drive a steel stake in to the scythes path - he won't be so chipper when he hits it

Possibly someone using a piece of wire to unblock the holes and piercing the membrane

Looks OK from what I can see.

I would guess Poundland or Primark

I was saying to measure the ring in different areas around its circumference to compare the thickness but was trying to say the thickness between the outer surface that contacts the bore and the inner that butts up to the bottom of the piston groove and not the height of the ring as if you laid it flat on a table! Ring wear will give too much end gap and will effect compression. Nikasil can wear due to ingress of fine woodchip, seen a few but not common.

Don't know what you are doing to them, I have found one or two get blocked and you get a vacuum in the fuel tank but it is pretty rare and the breather assembly is used on most Stihl equipment albeit with the pipe connector on the back on the MS200T.

A new cylinder and piston will give 170 - 180, a reasonably well worn cylinder will give 150 and is a little low but acceptable. Dropping to 125 is a bit low but probably OK for now, it is normal to get a 20psi drop cold to hot. Ported, it will pull 200 - 220psi due to dropping the base gasket!

No typo on my side???

I thought the breather was located firmly under the air filter back plate to the left of the carb and there is no way the item can be damaged and was unlikely to leak but what do I know!

You can put the rings in the bore and measure the end gap plus measure the ring thickness/depth (where it contacts the bore and the inner surface) in different areas of the ring to check for wear then replace if necessary. I would try to fit a Meteor piston or a complete top end if the bore is worn - they typically fail near the inlet port! If the rings are significantly worn then fill your boots!

Adjust the tappets, they always lose their setting!

Highly unlikely that the rod or crank is bent, they don't go that easily. I would usually remove the flywheel and clutch, pull the plug out and the saw should turn over easily. Fitting the wrong seal can cause the crank to be stiff but would be at all crank positions. If you remove the top end, it may stop the issue and if it returns when the top end is refitted, you are getting somewhere. A bent rod becomes obvious if you lightly undo the top end bolts so the cylinder is loose and turn the engine over slowly, holding the top end lightly in place. The top end will rock from side to side of the rod is bent. Most bent cranks I have seen have become obvious from the chain moving up and down excessively on the bar of the chain is loose, visually wobbly when the crank is rotated or impact between the coil and flywheel plus the engine will feel tight. Are you sure the cord was removed fully and the seals were fitted correctly?

If there is no external breather and the Cap hole is the only way for the tank to breath, the hole must allow for air to enter the tank as oil is used otherwise a vacuum will occur - swig in a bottle of beer and you will get to a point where no more beer will come out until sir is allowed in to replace beer swallowed!

Good luck with fitting a non standard coil, anything can be done but get it wrong and the saw will either be very boggy or pre ignite and cause serious issues. Close the flywheel to coil gap up to almost nothing, remove the kill wire, take the plug out, earth it on the cylinder away from the plug hole and pull it over hard and view the plug in subdued light. Many fail to pull the saw over hard enough and diagnose the wrong fault!

You can go off people!!! He has been quoted and will see what falls out of the tree!

I've seen it, usually found on saws that have been standing a while and the oil has thickened on the cylinder walls. You should try pulling a 298XP over or a vintage McCulloch!

Excess compression tends to be either fuel gathering in the lower crankcase due to a leaking needle valve or a build up of oil in the combustion chamber causing a very good deal between piston and cylinder. Not too much else left! Some saws do just have good compression and can kick but are generally 70cc+ in size.

If the flywheel has slipped very slightly then the saw will run but will be underpowered and may rumble a bit if the ignition is too advanced. I reckon your saw just has a slight bit too much ignition advance. New saws have coils that move the ignition timing around to make the saw easier to start and develop more power. Older ones had fixed ignition timing and would often rip the starter out of your hands if the starting method was a bit lethargic.

Knock...knock....feck that, fire up the chainsaw and go through it

The blast of evening cold air when you walk outside from a stuffy room on a summers evening. The first heat from the sun on your body in spring after a hard winter. First BBQ of the year, half a bottle of red and in to a bag of chilli crisps just before the meat is ready for serving.

Just pop off the flywheel and check it but it is probably OK. If you increase the distance of the coil from the flywheel, it will retard the ignition timing and help with severe kick when starting it. Try around 1.5 - 2 thicknesses of a typical business card but watch out - if you go too far, the spark may fail. Opening up the plug gap has a similar effect on ignition timing.

Idle is a bit fast or those clutch springs are a bit shot!

Which saw....365/372 Xtorq perhaps?