cornishman07

Tried twisting as far as I dare but it just springs back to how it is. I'm tempted to just fit it in the bottom groove and see what happens?! If it damages the piston or cylinder I'm no worse off really.

Update time; I cleaned the piston and barrel with the intention to just put the saw back together at no cost. After buying three different bits to make an adapter I eventually did do a pressure and vac test and crank seals are good, held 10psi on pressure -10 on vacuum, both held whilst crank rotated. Result! I finally had a bit of free time to rebuild it but when I came to reinstall the piston rings one of them was no longer a piston ring but a piston spiral!! No idea why as each of the three times I got an adapter for the vac test, that didn't fit, both rings were sat on the workbench perfectly fine ready to reassemble! What would cause this? Anyway, once installed it pinches in the groove and won't move so I assume it's not reusable? Drat! These are the original thin rings and not available any more so it looks like it's a new piston/cylinder and a ton less in my piggy bank! Double drat! On the plus side looks like the 181 and 188 have the same stroke and 2mm different bore so will be an 88cc monster once done! Might get a 28"bar then! Also noticed that right where the wires leave the ignition module they've rubbed through the insulation. If I slide heat shrink it won't get right in. A new module is 35 quid so I might just squirt a blob of clear ct1 once assembled and see how it goes? Still not got over the cylinder/piston yet, don't want to ruin my weekend before it's begun!

Thanks for all the replies everyone. I've familiarised myself with the difference between a compression test and pressure/vac test now so thanks for that! I was thinking about detecting leakage around the piston rings which is what I thought a scored cylinder might result in? Also to clarify the saw is a recent acquisition. I gave it a once over and took the exhaust off to look at the piston, which was scored slightly around the exhaust port. Don't know what caused it or when, but it did run fine and wasn't seized. Thanks for the suggestions as to the cause. Looks like a vac test is probably needed 🙄! There's no debris in the crank case and as it's around the exhaust not the intake can't see how it would be debris sucked in? If it was run without oil I suspect there'd be more damage?! If there's a leaking crank seal how would this lead to scoring the piston? Similarly how would a leaking fuel line lead to the same?

It's a 1983 and it's orange, not an army one. The piston is original with the two thin rings. Never done a vacuum/pressure test before and the half decent testers look expensive! Would be cheaper to just renew the bearings and seals regardless! Any link to a good value vacuum tester that'll do the job without breaking the bank? Can get a compression tester for about a tenner on ebay which looks exactly like a machine mart one. Would this not do the same job or at least confirm compression is ok regardless of any minor leaks? The suggestion something's leaking caused the scoring has got me paranoid now!

Cheers for that. I've taken apart a few saws in the past and this is by far the easiest to take the cylinder off, it took about 10 minutes, 5minutes of which finding my imperial Alan keys!! It ran fine before and was a beast to turn over. I don't have a compression tester but with the cylinder off I can see the squish band is relatively wide and compression chamber relatively small compared to other saws so whilst compression might be down it felt perfectly fine and was a bit of a brute to turn over! I think I'll clean it up and put it back together for nothing and see how it goes! I have seen meteor cylinder and piston sets are available for about a hundred quid and 288 cylinder/piston drop straight on appartantly so that's a future option!

Hi, I've taken the top end off my 181 to inspect some piston scoring I could see through the exhaust port and wondered if anyone could offer a second opinion if they're reusable?! I've cleaned them up with some emery and scotchbrite and there's definitely scoring on the piston. The cylinder feels smooth to the finger but using a fingernail does encounter very slight roughness on the section around the exhaust port. I can't tell if it's scoring or transfer! I'm leaning towards the former as rubbing down I don't think has changed it much. The saw ran fine before and I'd like to reuse if possible as it's all original, and it won't get much use at all as I've other saws. Any thoughts welcome!

Cheers for the replies guys!

Obviously they're not and this isn't a what's best or brand X Vs brand Y question but can chainsaw 2 stroke be used in a MX bike and vise versa or are there specific oils for specific applications? I've always used the green Stihl synthetic in the chainsaw/cut off saw etc @ 50/1 and Castrol or Motul 2t in my dirt bike @ 60/1 both mixed with super unleaded but I am thinking I'll just use the green Stihl @ 50/1 in all logic being chainsaws rev higher so should be fine in lower revving bike? I know it's not a big deal but it would be easier if I just had one lot of fuel to use!

Easy question to answer, you need either an 880 or 3120, and a 42" bar. Just depends weather you're a Stihl or Husky kind of guy?

Trick question, you need three saws minimum, plus a few back ups just in case anything happens to the first three!

I have seen those and they look great but I can't see any 16" .050 light type pro bars with a Stihl mount in stock anywhere? Plus they're triple the cost of the Stihl! The pro lam bars are about the same money but they're not in stock either! I really don't/won't use it much so durability shouldn't really be a problem.

It's only for firewood and cleaning up so shouldn't take too much abuse and I've treated myself to an ms400 (which I might try one of these hexa chains on) so will only be used occasionally for small stuff. I'm going to put a 16" 04 light bar on just to see what difference it makes. I was thinking to give the saw it to my stepfather but I'm very attached to it so I've decided to keep it and I'll buy him a different one! Is it normal to have a sentimental attachment to a chainsaw? I think it is! anyone else?

Thanks for the replies!

I'm wanting to put an 04 light bar on my 024. The previous bar/chain was 1.6mm width and the 04 light bar/chain is 1.3, both are .325. Will I be able to use the same rim sprocket or does it need to be specific for the width of the chain/guide bar? Thanks!

Hi, I need a replacement bar for a still 024 and whilst looking at what type of bar mount noticed there's no inner side plate. There's two options listed. Can anyone help with which I need? It's a 1997 model with 2 bar nuts and front tensioner if that helps!

I went ahead and ordered the 400 which arrived today. Thought it was much bigger but there's really not that much in it!

It's a 2013 model so yes an older saw. I seem to remember the 261 being one of the first mtronic saws stihl did and I got the last carb model they had in. Its a while ago now though! The bottle is actually some of stihls premix which I've periodically started it with to stop it gumming up!

Thanks for all the replies everyone. What a coincidence 90% of them say keep both! I knew that would be the case before I posted! 🤣 I'm not in the arb business hence being a member here for 7 years and not posting, don't have much to add! It's for general use on the farm so either saw is probably overkill, and keeping both is pure folly! I've gone ahead and ordered the 400 which I got for £870 with a 20" bar and chain. By the time I claim back the VAT and knock it off my taxable income it'll come in about £450 so if I sell the 261 it should easily cover it and practically be a straight swap. Maybe I should have asked if you just had one saw which would it be? I wont be using it all day or up a tree either so the extra kg of the 400 shouldn't matter too much and most importantly it's bigger and better than my brothers saw!! thanks again for the replies.

Hi everyone, probably not a usual which saw thread, but there's a bit of a back story. I have a brand new ms261 in the loft which I got as an insurance replacement for a stolen saw. I got a used 024 to use whilst it all got sorted but it's been a super little saw and I never got round to using the 261. I'm letting my step dad have the 024 now so time to use the 261. Or is it?! I'd always fancied having a go at modding the muffler, maybe smoothing the ports as I like tinkering and to make it a bit more powerful for bigger stuff and to run alongside the 024. Since then the ms400 has come out though which I'm really leaning towards. It's more cc than the 261 so probably not a fair comparison. Obviously the 261 would cost nothing but I've seen a good deal on the 400 and I could sell the 261 and put the money towards it. And I can always borrow my 024 back for small stuff if needed. Any opinions greatly appreciated!