spudulike

Is the exhaust outlet standard or pointing at the brake handle?

The grey plug colour is where the piston has overheated and the aluminium has vaporised and spattered on to the plug. This is the stage after being white (overheated). The piston has partially melted although the saw has continued to run. I would say that the melted aluminium has probably worked its way down to the main bearings. Typically this can cause the saws bottom end to make a "hollow" rumbling sound, I had the same on my 357. What do you need to do the job - experience or/and a decent dollop of engineering skills. The main difficulty is how you do the actual splitting of the cases - I did do a tutorial on a 660 some time ago on my "whats on your bench" thread. I have pics of what I used - a BIG G clamp, a splitter - donated by ADW (Many thanks) and a homemade splitter - two pieces of angle iron. Don't use a big hammer on it, a positive is that this machine is BIG and is therefore easier to get splitters in. Once you have all the bearings and crank in, the crank will feel tight so bash each crank end with a copper mallet to take any stress out and the crank will become much smoother to turn - like silk.

Should be "An Iron"🙄

In addition to my earlier post, a repaired seized saw should be pressure and vac tested, the carb overhauled and then tach tuned. You need to ensure that the reasons for the seize are eliminated otherwise it is likely to go pop again. These tests will also ensure the new seals are sealing well. On the running lean issue, are you seeing the idle racing, light plug colour, flat out revs too high?

Probably main bearings. The noise of bad main bearings resembles leaving the saw running on a concrete hard standing, a heavy rumble from the bottom end. With the top end off, the crank spinning should be super smooth when you rotate it holding on to the con rod with the piston not fitted. Possibly debris has made their way in to the main bearings and won't show as play in the crank....if you do fit new, ensure you "de-stress" the bearings by whacking the crank on both ends after putting the cases back together again.

I have burnt laburnum and can confirm that it didn't kill me👍not saying it isn't dangerous but burning it isn't like catching bullets in your teeth. A very heavy wood.

Shame you don't have a guy two miles down the road to sort them overnight.....good times👍You helped me get started in an indirect sort of way...thanks.

Looks like bamboo rhizomes to me. Dig them out and glyphosate any green bits that come up as the larger types are very invasive if I am correct.

Those screw in piston stoppers can damage the crown of the piston so the Stihl plastic "dog bone" one is generally the tool of choice for me but do have a modified spark plug for engines with the plug hole at the top of the cylinder - typically mowers. Rope does work well but you need to ensure the ports are covered by the piston before using it. To remove the busted bit of the piston stop...probably just shake the saw around, a torch and a pair of tweezers. If that doesn't work, try getting it out of the exhaust port. If that doesn't work then it is a cylinder removal...grrrrr.

Look at it as a relationship and see if you can get future loads of wood or do a bit of clearance on windblown etc. Just make sure both parties are happy at the end and the door is open for the future.

I thought these bee hotels were all Nobby bollox but was surprised my one was used so much and still is. Glad yours is becoming fully booked up👍

Blimey, how the other half live, must be a decent life up there👍Nice job BTW.

68 Guns, decent anthem from the 80s👍

Good luck with that, at £250-350 per hour and generally advising mediation with posdibly a neighbour with the computing power of an ameba or totally intransigent, it is all ball ache. Can't you either go off the deeds or just agree to get a mutually acceptable land surveyor to determine where the boundary is? Much cheaper.

Mmm, I know what you mean, apparently I am talking bollox and it can't happen...what do I know having had a fair number apart and owning a ported pop up piston 357 which rips your arm off....with the decomp valve pushed in on starting!! It never happens 🙄🙄🙄

Missed this little thread....the 357 is very prone to spinning the clutch off when you rev it and snap the throttle closed just after the clutch has been off. This has the effect of the clutch partially loosening and then doing up again out of mesh with the pinion. The way around it is to rev the saw up and snap on the chain break a few times or just rev the saw up and cut hard in to a big lump of wood both without letting off the throttle. This locks the clutch on.

Nice job and the advice I speak is one of experience...as always. I made a bee hotel and was amazed by the uptake BUT....the bloody birds liked pulling out the bamboo bits so...a piece of wire grill over the front sorts this out...or glue the bamboo in place - perhaps you have and I am preaching to the vicar. Good thing to do and they do actually work......a few long flowering salvias, cosmos, nasturtiums and marigolds nearby makes it really good.

The plug colour takes a while to form. Black colour may just be a dirty air filter, big mower and small garden where it isn't warming up, the mower may not be revving properly. I had issues with my Atco Royale yesterday, turned out to be water in the petrol....that's ethanol for you, all running well now.

Looks a decent swing though....just saying!

Black plug = running rich. Mower carbs are pretty basic and most rely on the main jet for fuel delivery and have little in the way of adjustment so....I would say that your choke may be sticking on partially which would make it run rich. I don't know how your choke functions but some have a heat activated solenoid, some have a manual choke lever, some operate off the throttle and some just have a primer bulb (No choke). You will need to whip off the air filter housing and see how the flap nearest the outer part of the carb is operated. Having done this, at cold and in the starting setting, it should be fully cold. Warm the machine up and when fully warm, it should be fully open. If it isn't, it is either set wrong or whatever opens and closes it has failed. BTW, typical carb issues are blocked main jet, emulsion tube holes blocked, crap in the float bowl or leaking needle valve. The OEM carb will generally be better quality than cheap Chinese.

In the first pic, it looks like the saw has been revved up without cutting as the oil is coming from the top of the cover. We will wait and see what happens now!

I would check the clutch shoes are moving freely as if they stick out they will cause the symptoms you have. Are the idle revs excessively high where you would expect the blade to spin on idle.

Glad it is all OK and it seems similar to the suggestions I made. I had similar on my Rover mower which wasn't switching of or starting well and turned out to be a dry throttle cable lacking full travel plus the obligatory carb issues...all good!

The problem would most likely be that the longer shaft gear is being pulled against the smaller gear when you are fitting the cutting head. You just need to work out why this is happening. I don't have the part in front of me but you need to work out why. Just looking at the parts list...bearing 9 could be too thin - are they OEM and fitted in the correct price. if washer "4" is missing, it would have the same effect. If bearing "8" isn't seated correctly then the same..... Is part "15" fitted as without it...the same condition as it would appear to secure the last bearing.

The saw never had a paper gasket in this area so it won't need one now. I would think that the oil pump may be leaking oil from the oil pump pinion shaft. I state this because I once had a 372XP in doing the same and it was just a worn oil pump and replacing it sorted it. Are you sure that it isn't just excess oil coming from a pump set too high? it should only need to be set that way if using a bar to the top of the spec - probably around 28". Is the saw leaking in use or standing? There are seals on the pump inlet and the outlet that are worth checking.