spudulike

Everyone says that their bore is "Scored", a score is a gouge in to or through the NiSC plated bore. Very often, the piston surface on the exhaust side has started to melt on to the cylinder bore, this then locks the rings in their grooves, compression lowers and the engine seizes. Very often, this "Aluminium transfer" can be removed with acid or alkali to reveal a near undamaged bore underneath:thumbup: To put it in to context, I have around a 98% salvage rate on seized cylinders that have gone like this. You will find that the OEM bore gives a better piston to cylinder fit, the port timing is better, the port bevels are better and is generally far better manufactured. Personally I always try to salvage the bore and fit a quality Meteor or OEM piston as this gives the machine a better chance of long term service after repair. The original cause of seizure should be found and rectified - if it was 100% bad mix then fine, it is done already but I always do a number of checks on a repaired machine to set it up correctly. If all else fails, I would fit aftermarket and Hyway are not bad but you can't expect a £65 P&C kit to compete on life expectancy with a £300 Mahle kit!

Remove the spark plug, insert either the Stihl double ended plastic (dog bone) piston stop or wind the engine in normal direction until the piston covers the exhaust port and use a length of recoil rope down the plug hole. Don't use a metal one as it can damage the piston crown! It is sometimes easier to remove the starter cover as it has a ratchet effect on turning the engine in reverse direction. Having locked the piston in position, the clutch needs to be spun clockwise )opposite from normal. I believe your clutch has no hex nut on the end so in absence of the Husqvarna tool. you can use an old screwdriver and mallet to tap it round on the central spider casting to undo it. Don't go too close to the end of the central castings arms, you may just shatter it. Try lots of lighter taps rather than hammering the crap out of it - they can be anything from dead easy to a right bitch - you can make a removal tool from a socket or piece of heavy gauge pipe and bar but the screwdriver method usually works for me.

What is wrong with the cylinder? Us it aluminium transfer or are there scores in to the cylinder. The OEM part is generally much higher quality. Do you know why it failed?

Do both, not sure if you are asking as you are trying to fit either on the same bottom end. The 254 ports up very well, ou have to be careful with the squish but there is plenty that can be done and usually includes widening of the exhaust and inlet ports, lowering the lower transfer and a bit of re-shaping of the upper fransfers and inlet/exhaust ports. Also the air filter can be modified, there was a rumour that the 254 was made a bit quick and was too close to its larger brother 266XP so they restricted the intake and it can be opened up:thumbup:

Just what I was thinking - the teeth on the spur sprocket need to MESH with the segments on the white oil pump drive. If it doesn't, it will cause issues with the back of the clutch tightening on the clutch drum rather than the flange on the crankshaft:thumbdown:

I just use a cheapo Silverline one but have modified it with a speed control, it now grinds and barely produces any heat. As standard it used to fry the old crud around the tooth and discolour the red marker I use as the start point. The sharpener now just grinds and no heat build up just takes slightly longer! Sharpening chains is one of those jobs I hate - fine on a 2-3 strokes on each tooth on a dulled chain but one that has been toasted a bit:thumbdown: bloody monotonous job especially when the file stops biting in so well! People knock grinders but they give a consistent finish and good results if used correctly.

Blah Blah, it will be fine:thumbup: You may need to change your fuel line and fit a new carb kit as once the petrol is removed, the rubber tends to shrink and go hard causing leaks. If the saw is in good fettle and these have been done recently, you may get away with it. Barrie - like your new logo:thumbup:

Use the Stihl plastic double ended stop and spin the clutch off clockwise to undo!!

The fact your chain brake is stalling your saw means that there is binding between the clutch/crankshaft and clutch drum. This must be sorted before looking at anything else. Is this an 020T or the older metal cased 020AVT? Fitting a new carb kit tends to improve a saw a little but is no magic silver bullet against all issues.

If the saw is racing, THAT is the reason the chain is spinning. Check the throttle linkage is closed properly and not snagged or catching. If this is OK, I would suspect an airleak or something has come off such as one of the connector pipes etc. The autotunes will hide an airleak by adjusting for it but once it goes beyond this, it may be the death of the saw so get it checked out if it isn't the linkage or the carb come loose etc

All the things I would check. The only question I have of the OP is ....is the idle speed what you would call normal or is the saw racing at a higher than normal idle? One addition - sometimes that plastic twine gets wrapped round the crank and impinges on the crank to drum clearance - worth checking if you have been working near this stuff.

Just started work on an old 162SE, compression is over 170psi and it all looks in pretty good nick. Had to change the throttle and safety interlock mechanism and fit a new diaphragm but reckon it will be up and running shortly:thumbup:

I have just started working on a 162SE from my collection and can say yours IS a 162SE! The other, looked a bit like a 280 or 380 to me!

I had a hire car in Coatia, from the first 100yards we had a tapping noise and thought it a stone in a tyre. A day later, 80mph and had a blow out on their biggest motorway, managed to haul it over andd get the tyre changed with mad Germans coming down the highway at 140mph! Although there was nothing in the contract, and would have been none the wiser if I hadn't pointed it out, they said we would be liable if the tyre needed replacement - turned out to be a £5 repair and he explained to me about a vulcanised repair:001_rolleyes: I gave him one of my firm handshakes when we parted - think I could see his eyes watering:thumbup: They are crooks and the customer pays for everything in their eyes!

Part Number 544 02 83-01 appears to be the correct one from the IPL I have! It should have the top exit, double front bracket and no baffle! Also very easy to modify - just open up the exit hole with a dremmel:thumbup: The 85-01 appears to be the Etech which I presume is the CAT version.

Sounds like it is the old 45cc one, it would work but would cut the performance.

Simple, the jaw type thing goes round the back of the worm drive and the bolt pushes on the crank end and pulls the gear off:thumbup:

Did I tell you how much I hate Stihl 039/MS390s....... I always have issues with removing the long bar stud that goes through the plastic cradle from the bar mount in to the engine. The one I am working on, looks like it has been worked on before at some stage and guess what, the guy has put a nice big dollop of thread lock on the bar stud....got to be careful how I spell that:lol: I have used the normal two nut method to shift it, decent grips on the inner flange, heat, oil, drilled and pinned it, will it shift? The HELL it wont Grrrrr:sneaky2: In the end, I ground off the end with an angle grinder, drilled off the recessed flange with some very useful Colbalt drills, removed the cylinder and drove the butchered stud through the plastic cradle and removed it from the lower clam crankcase by grinding flats on it and putting it in the vice! Got it all done in the end but what a bitch:thumbdown:

Relax, I have used a conventional hone to break the glaze on all seized machines over the last couple of years. I took the plunge when I had a MS660 in with three years on it after similar treatment and the bore was good. Nikasil CONTAINS Silicon Carbide, you are putting a little roughness on the bore so the rings can bed in quick. As long as the hone isn't used to REMOVE the transfer, all should be just fine. Lots of methods will work, some may be frowned upon but doesn't mean they are not valid in ones own environment!

There are always a number of ways to look at the same thing, I was interested to find more about this and read this PDF which answers a number of questions but does contradict much of what we all do - http://www.mt-llc.com/pdf/98winter_snowtech_article.pdf Firstly the porosity appears to be caused by air holes in the bores aluminium casting and is in fact pitting! Not quite the same as the plating being porous and letting fluid etc through - I couldn't understand how this could be with something so damn hard as Nikasil! Secondly - Nikasil is a basically Silicon Carbide suspended in a Nickel carrier, Silicon Carbide is pretty close in hardness to Diamonds! I knew a bit but this is interesting. Nikasil also allows coverage of oil on its surface where Chrome doesn't. Thirdly, this article states ball hones should not be used on two strokes due to the balls damaging the ports and recommends FLEX hones which are basically nylon brushes with abrasive material impregnated in to the fibres. It ALSO states that conventional hones shouldn't be used - in reading the article, it is perhaps aimed more at a newly plated cylinder that needs a machined honed finish to complete the process rather than the sort of honing or TBH, glaze busting that we are doing. It also states that it isn't as important to hone a plated cylinder as a cast iron liner! BTW Carborundum IS another name for Silicon Carbide so not sure the difference between SI paper and stone:confused1: So - from my side, after cleaning the cylinder from the aluminium transfer, I will still use my traditional two legged hone - I always use oil and use the hone sparingly just to break the glaze and clean thoroughly afterward. Why will I carry on with this method - each ball hone size only covers a small amount of bore size and the ports may suffer damage - I usually take great care with bevel when porting and have noticed older bores (probably chrome) are pretty fragile and can chip easily. The flex hone seems like a better option, may think about getting one but I have a number of long repaired saws out there using my standard method and have had no complaints or premature failure to date. Matty F had a borderline MS260 that had about the heaviest hone I have ever done - it was still running as his dads "go to saw" one and a half years later:thumbup:Perhaps he can give us an update! We can all get hung up on the technical stuff and each guy will have his own methods or copy others. All I aim for is a repaired bore that will allow the rings to bed in PDQ maximising compression and retaining the longevity of the saw. From experience, I am doing something right!

A bit blurry but reckon it would clean up!

Thanks Joe, I have got one on order and hope that will do it, I did try a big French banger but just covered the lawn in soil and annoyed the neighbours:blushing:

I would imagine your local Husky agent would love to help. I would suggest you put on your next post, the size saws you prefer - I would imagine a top handle, 50cc, 70cc and 90cc would be typical! Welcome to the site:thumbup:

Lightly sand the aluminium transfer, apply the acid with a cotton bud to the effected area, if all is good, it will fizz. Once it has gone black and stopped fizzing, lightly rub with more wet and dry, try more acid and if it fizzes repeat until it doesn't. If it doesn't fizz, all the aluminium has converted to Oxide and can be lightly sanded off. Most acids will attack aluminium, it is something to do with the amount of electrons in the outer shell of the atom, 3 in this case and the acid reacts with the metal to make a salt and hydrogen hence the fizzing - the salt is the black shyte you will sand off! Sulphuric is fine as is Hydrochloric (Muriatic) acid as well as a few others. You want to use non concentrated and it is easier to get hold of - 15% would work fine and the proof is in the fizzing that starts when you put it on the aluminium. Time scales - around 30 mins to do a reasonably caked one but don't leave it without checking regularly and clean it down thoroughly once done - eye protection is a damn good idea! If you get the fizzing along a vertical score, go easy as you may lift the plating - the stuff on old machines is much more brittle than the new plating - found this out when porting! Good luck - the first 10 are the most difficult:sneaky2:

Good luck on that one, the customer gave me a maximum budget, my repair was advised to be more and unfortunately:sneaky2: the budget was changed:lol: