spudulike

The cylinder lining /plating very rarely wears out - only seen a couple that have gone and mostly due to inress of crap through the air filter. If it has seized, then as Ray suggests, fit a new piston and salvage the cylinder. It is very rare where one gets scored that bad it cant be cleaned up with the usual methods.

Stop bragging and hand over the dosh before we can find your friends Grandad:lol:

I can't believe Stihl would let third parties, Chinese or other use their moulds????? Typical issues of aftermarket kits are brittle rings, dodgy circlips and poor piston fit!

Well it shouldn't have seized then, best remove the spark plug and see if it will spin over and if that doesn't do it, remove the recoil cover, get a socket and wrench on the flywheel and see if the engine will turn - it may be something simple or possibly a busted ring! Other than a busted ring, may be a busted circlip or something jammed above the piston or in the crankcase - just go step by step!

Yup, trying to start with a 10mm hole isn't easy!

When you used it, did you put chain oil in the front tank and a petrol/two stroke premix at 50:1 ratio in the rear/handle tank? Or was it neat petrol:blushing:

And.....the budget:001_rolleyes: My Husqvarna faves - 357XP and 346XP, both will do what you want but factor in £300+ for one in nice condition, they are getting rare now but everything is manual not auto tune so easier for someone like me to service. Less money - 350/345, both good saws for homeowner/semi Pro New - 560Xp and 550XP - both autotune and probably the 560XP the better of the two. Stihl - MS260 - some like it, some hate it but very popular MS261 - again. some like it some hate it but it does have the tendency to eat clutch needle bearings. MS361 a little larger - not used one but supposed to be good! It all depends on how much folding stuff you have!

Been very busy as always, lots of kit flowing and ebbing:001_rolleyes: Just rebuilt a 242XP, the piston had signs it had seized and cleared, dropping the base gasket built up good compression but it ran like a bag of nails with lots of free porting around the inlet skirt so fitted a new one. Got it back together again and had some weird carb tuning issues - it would run rich and then BANG, straight up to 15300 rpm - the clutch side seal had leaked a little under vacuum so decided to change it and have yet to tach it but have gone as far as I need to - Oh - carb kit fitted as well! 576XP - seized and the cylinder was a bit pitted where someone had attempted to salvage the cylinder and left the chemical on:thumbdown: Cleaned and smoothed the cylinder, new aftermarket piston - just wasn't sure the cylinder was up to a new OEM one and will see how it goes - starts and runs OK and a relatively cheap repair. MS201 - the chain running on and the carb having little effect on the saws idle. Cleaned the carb and still no effect, drilled the H screw limiter so I could adjust it - no effect, checked the clutch side seal by pouring thick oil on it when running - no effect but did notice the revs changing when the saw was at different angles - found a split inlet manifold - now one on order. A 346XP (NE) - seized and filthy - brake handle buggered and parts missing:001_rolleyes: I have a scrapper so pulled the parts I needed, cleaned the cylinder which came up OK, bevelled the exhaust port and rebuilt - the clutch side seal had an epic leak under vacuum and pressure - bingo, that was the route cause of failure so have just fitted the new one, retested and is ready to tach - looking a damn sight cleaner than before:thumbup: Now got two 550XPs to build in to one working machine - a two day old one got a direct hit resulting in a broken crank case brake handle mounting lug. The owner has struck a deal with the owner of a buggered one that came in so will rebuild the parts in to a working saw....hopefully:lol:

These choices always start with budget and you also need to consider PPE if you have none. Would you consider second-hand or must it be new?

What you are doing is allowing the exhaust gasses out faster and allowing the carb to charge the combustion chamber up more efficiently. Drilling the exhaust does get the saw cutting harder - it is probably worth turning the H screw anti clockwise as far as the limiters will allow and keep an eye on the plug colour but you shouldn't have any issues. Just make sure that no metal swarf ends up in the exhaust once done - I have drilled a running saw before now to ensure the inside of the muffler stays clear of metal particles but make sure the brake is on! Start with a 5-6mm and end on a 10mm - One thing to bear in mind is if you employ workers and this is a saw you give to them to do there work, you may fall foul of the HSE if you mod it and there is an accident requiring over 2 days off work so go careful. If it is your own saw for personal use - go to it:thumbup:

How about most of the saws I have had in during the last month - boxes of bits and "I know it is old but can you fix it for a tenner"? It is when the majority of the saw is filled with woodchip and oil I reaalllyyyy love it:sneaky2: Beginning to see the saw for the shyte now:thumbup:

Splined round - http://www.4husqvarna.ro/fotky8943/fotov/_ps_4HUSQVARNA-135-IPL.pdf Hope this helps - go easy on the H screw, if you don't have the correct setting or a tach then I would set to 1& 3/4 turns out and screw in until the revs clean up but don't soar and then look at the plug colour after a few big cuts. Coffee brown is good:thumbup: The saw should "Fourstroke" a little on the top end and clear during cutting.

It most probably will have a splined round H & L screws - you can sometimes use the plastic end of a crimp connector to move the screw and I have taken them out before and slotted them. Most carbs are set to one turn out each, there are exceptions but this setting generally gets the saw going well enough to adjust the L screw first and then set maximum revs with the H screw.

Thoughts - yeah, buy a two stroke:thumbup: These sort of projects can take days of work and still not work so don't go too mad, it may well be not worth it!

Once had a MS880 in with the H screw set to 1/2 turn, needles to say, the piston had expired!

Look at the amount of moving parts in a four stroke engine compared to a two stroke - all the timing on a two stroke is done by a solid cast aluminium cylinder - the only thing that moves is the piston and bottom end. Compared to the 4T engine, you have valves, tappets, cam followers, cam, timing chain, timing chain tensioners, advance and retard mechanism, gears, valve springs, collets etc etc. Now tell me that this is an improvement over a simple cast cylinder with no moving parts:confused1: I worked on Wolfies KM100s, got it working fine, a week later, it was back - I had to kep adjusting the tappets and we gave up in the end as the next thing was to start stripping the engine -under 30 mins on a two stroke, much longer and more complex on the four stroke:thumbdown:

The piston looks OK, the valve seat may be able to be ground in, look for a nice grey seat around the full circumference when done - do the other and compare. If it isn't good, you will lose compression and burn the valve out in time - if you have time, try it. I admit to hating these Stihl 4T engines and not having had many on my bench, two strokes are far simpler and have never seen valve issues with them:sneaky2:

Sounds like fuel restriction - under load , the saw needs more fuel and lack of it is stopping the engine making full power. Before diving in to the carb, it is worth removing the muffler and looking at the piston through the exhaust port. If there are any vertical scores (not small scuffs) then you have real problems. If the piston is wet and grey silver with no marks, then you need to remove the carb and it is worth removing the cover tht is held on with one screw - there is a wire gauze strainer in there the diameter of a pencil and it is common to get fine wood chip catchng in there. Other than that, you may have a holed fuel line - it is possible to remove both ends plug one end and then suck and stick your tongue over one end to see if it holds vacuum, I prefer a pressure gauge:thumbup: It may be worth opening the H screw up 1/4 turn (anticlockwise) but be careful as if you turn it too far clockwise, you may melt/seize the piston!

If you rev the saw flat out with the bar pointed at a log etc, you should see a line appear within a second or two. The oil tank shouldn't empty before the fuel tank if both are full before you start - as Steve said!

I also believe that in a fight, a grizzly bear will see off a wolf:thumbup:

I think we can conclude that the MS261 is like Marmite - perhaps that is what we should call it from now Marmite261:lol:

The saw not idling - try making the coil to flywheel gap smaller, had twom"non runners"that leaped in to life after a quick tweak:thumbup:

I have never seen or heard of a tuning kit for the MS200, you can buy aftermarket big bore kits and dual prt mufflers for the big stihls but nothing for the MS200. The muffler mod is the simplest mod but I do far more than that inside my engines and have developed my techniques over the last few years to make the saws stronger in the cut! It is all about compromise, time and skill - if you have 10 minutes, a big hole is a simple mod and I also always pressure and vac test engines as many saws that owners have sent in have had leaking crank seals so have repaired before returning the saw. The porting will generally protect the saw as it will run a little richer and faster but tuning is not just about quick easy mods - the base machine has to be sound before tuning is done. The MS150 and MS201 ARE saws that a hole in the muffler is a decent easy option, the MS200 has further gains that can be made!

The one thing that is baffling in all this is the dry plug you mention because the rest sounds like a leaking carb needle valve which will make the engine not run well if at all and will flood the engine at standstill. A new full carb kit would be good but it is worth checking the carb metering arm height and make sure the spring under it is correctly in place. I would normally pressure check the carb but lacking that equipment you may struggle. If the engine is suspected to flood, pull the plug, turn the engine so the plug hole is downwards, turn the ignition off and pull it over fast a few times. My money is on fuel - worth checking the fuel filter and line and if it plays up again, see if loosening the fuel cap helps. Also make sure the compression is good, if you have a bright small LED torch, shine it down the plug hole and try to look at the exhaust port side of the cylinder wall to inspect for scores. All these engines are similar and operate on the same principles.