What's on your bench today?

[gand]

On 23/04/2024 at 12:56, jimug said:

Hello! Following some good advice from @spudulike @adw and @Stubby to not bother doing anything with a Husq 340 just because it was cheap, I failed the weakness test and got hold of an 034 because it was 'really' cheap and didn't 'look' in bad nick at all. Was hoping it'd be a shot fuel line or similar. It's a piston scored on the exhaust side only, and a small amount of transfer inside the cylinder (to my eyes anyway, I had never seen inside one until I looked at this one)... plan is to put an aftermarket cylinder and piston on it, and possibly the crankshaft oil seals since they come with the kit, and see how it goes. If I learn something about chainsaws and engines as a result I'll be happy...

Are you able to clean up the cylinder? Then you might just need a piston 

[jimug]

@spudulike @gand I don't think it's an OEM cylinder, no markings on it and it has a cooling fin cut off so assume it's an 036 one. Given that and the cost of an aftermarket kit I may use the old cylinder to have a go at cleaning it up, but put a new one on anyway - but definitely note that I'll need to pressure / vac test @Stubby. I think I know what to do there and plan to use a bit of inner tube behind the exhaust gasket to seal that end. At minimum I'll need a new cylinder gasket as that was in bits when the cylinder came off.

Piston wise as well as fairly deep scoring (way deeper than just being able to feel it with my thumb nail) it looks like the rings are mashed into the grooves

So far treating it as a learning exercise. I'd rather have this saw in bits than start messing with my 135 that works fine and would rather it stays that way (notwithstanding I now have a clutch spring to fit as per other helpful advice), but as and when it needs work hopefully I'll have an idea what I'm looking at.

 

Thanks for all the input so far!

[Muddy42]

My Stihl MS 460 has been having minor oiling mysteries.  After 20/30 minutes of use the nose sprocket seizes up.  Its a fairly new (first chain) 20 inch Stihl rollermatic bar 3/8ths pitch. On inspection the chain feels dry and I simply clean out the groove and free up the nose sprocket with wd40 and a screwdriver then regrease with my fingers.  This happened twice last Saturday.  BUT during the time I used a tank of fuel, the bar oil tank nearly empties so oil is going somewhere. The adjustable oiler is at max.

 

Back at the workshop I did some further checking.  The oil pump area was still clean and the lines didn't have cracks, but there was masses oil on the inside of the bar and on the case below the bar. I cleaned the saw up and ran it again. I couldn't get oil to flick off the end of the bar and the same mess emerged on the bar. I ran it without the bar, chain and inner guide plate - oil is emerging out of the oiler. My current thinking is that oil is pumped out of the saw but is somehow not reaching the bar's oil hole. Recently I replaced the worm gear, oil pump and flushed out the oil tank with petrol.  

 

Current thinking:

 

1) The inner guide plate is pretty smashed up and bent, maybe this is causing the issue.  I have ordered a replacement (1128 664 1001) but have just found out there are two alternatives.  See below, is 1128 664 1002 any good?

 

2) I've read that some people open up the oil hole on bars. This seems a bit drastic.  Does anyone have any experience of this? Thanks

 

[spudulike]

On the two plates, No31 is by far the most common and if held on by a single screw, it is the one you should use.

With the oiler, on any setting, it should always fling oil from the tip off the bar when pointed at a clean piece of wood and revved. 

Were the replacement parts OEM? Have the crank seals been replaced? sometimes people don't push them in far enough and sometimes they can lock the pump up as it bends the pump when clamped.

Is the bar oil hole clear of debris? I have seen seasoned pros wonder why the oiler isn't working and this little hole is blocked.

It sounds like the oil isn't flowing in to the bar but is flowing behind the mount plate, just check the surfaces of the bar mount are clean and flat, hopefully the new plate will sort it as it is a pretty simple mechanism and shouldn't give any serious issues.