bmp01

Just once so far. I have some joiner links arrived today. But also wondering about new chain if its going to break often from now on. Chain and bar not getting hot but they do look 'dry' to the point that after each plank I run the saw out of the wood to ensure chain is thoroughly oiled. Its oak that's been down for 5 years or so, still damp in the heart wood though. Auxillary oiler would be an advantage...

Newbie to milling question about chain life really. Would you expect to get the full tooth life out of a chain used for milling or is it typical to bin the chain after say a 1/2 or 2/3rds tooth wear ? Let's assume no chain damage through its life, just wear. Reason for qu - I've busted an Oregon 75DPX chain where the chain has been used for milling the majority of its life. To be honest it doesn't owe me anything, for the cost of the chain I've milled a good deal of oak. But well ye know the chain teeth still look very servicable and the links still feel pretty tight. Power head is a tuned up Husky 395XP, chain is Oregon 3/8 regular, chamfer cutters, ground to 15 degrees. Chain did see some metal a while back but very minor just dulled the teeth and quickly fixed with routine file sharpening. Failure was through the preset joining link which always makes me suspicious. I'll see if I can find a picture.... Thanks for any input.

I'm torn between 'cheeky fecker' and justifying the experiment statement along the lines of real life experience .... valued by manufacturers ,... blar, blar Think we'll go with 'cheeky fecker'

Nice one. I use the Stihl Super already, no complaints to date. I'll not worry so much about it hanging around in saws.....

Thanks for that last bit - useful home experiment 👍 Can we assume your experiment was undertaken in shed type conditions ie cold (winter) and hot (summer) ?

I read it that it was heat from the outer surface of the twin wall within the plaster board duct - which is fair game IMHO, providing some thought and precautions go into it. Opening up the twin wall obviously not a good plan... no point discussing .... Can OP clarify intentions ?

I'd be checking your repair shops claim before going too much further, not saying they are wrong but I'd be wanting to know what the evidence was to draw the conclusion they did. Pull the exhaust off and have a look at piston - that's easy enough. Did the saw stop unexpectedly - you said it wouldn't restart. If it has trashed the piston I would have expected it to stop running by itself. When I rebuilt the top end on my secondhand 395 (lots of hours ) I did the crank seals as a precaution. Sure enough the flywheel side had been leaking, lots of muck on the bearing cage on that side, lucky to have got away with it I guess. The only other thing - emptying fuel is good plan but make sure you then run the saw until it's dry otherwise you are just leaving fuel in the carb to evaporate away.

More likely its the thing the electric motor is attached to and the job its doing. I mean - I dont imagine these people just switched on their electric motors and just sat there holding 'em all day 😃 (maybe some did...) Macpherson got it right - manufacturers cant quantify vibration in use, too many variables.

I'm still of the view that the vibration of an electric motor spinning by itself is insignificant to almost every thing else in the real life cutting wood situation. I think the chain and vibration due to cutting is the key to it. When you consider the guide bar is isolated on the petrol chainsaw (it being mounted to the engine which itself is av mounted to handle) where as the guide bar is directly mounted to the handle on an electric saw. In this case only the flexibility of the plastic handle can dampen the vibration. There isnt much weight in the handle to help either. As an aside, I witnessed a sharp chain with uneven tooth lengths gave a good deal of vibration at the handle, which disappeared once tooth lengths were evened up (MS201T, sensible high chain speeds, wire spring av).

Nope... Must be vibration of the teeth cutting the wood though - its certainly not from the elec motor.

Thanks for that, there's one going cheap nearby might be worth a punt then.

Anyone got a view on the Lidl electric saw ? Think it's sold as 2.4kW which ought to be enough, no idea about chain speed though. Anyone played with one?

Can you come up with a way to drive the oil pump without the clutch in place or engine running? I'm thinking battery drill and an adapter or rubber drive drum (like the rubber drum you have in a demel kit for the sanding drum). Blank off the outlet to the bar, as youve done already. Spin the pump and look for leak. ...

Yeah....but.... The outside of the bar is what it is. It's the inside working bearing you need to see but of course you can't. The only thing you might gleen some info from is the sprocket (not the nose assembly but the actual sprocket), so chain off and inspect down to the root of tooth form. Look for coloured steel indicating heat. I'm guessing your planning on running it anyway. 1) Cross cutting would be a safer way to assess the nose sprocket assy and build confidence. 2) Your milling attacement is still too close to the nose bearing IMHO. There is a void just back from the bearing, where the sprocket teeth would run. CIamp into solid metal back from this void.

Think I'm with adw on this, the metal bits that are made hard in manufacture by heat treatment have most likely been re-heat treated - meaning they will now be softer than they should be and not last. The scortched paint tells where it got hot. The thing to note; its not just hot where it was pinched .... I'd say the (nose) sprocket itself got hot and subsequenly transferred the heat to the near by bar, hence the circular pattern of scorched paint. For the little sprocket to put that amount of heat into the relatively bIg bar I'd say it got very hot. And if the sprocket got hot so did the needle rollers, these are (were ?) both hardened material parts. If you take the chain off and clean / degrease the nose spocket can you see if it has gone blue ? Edit: heat pattern is inboard of the nose sprocket, looks like it matches with where the rolling bearing is....

Ah, thanks for feedback good to have some run time on it. T'is the final confirmation the gremlins have been driven away.

So swap the old 'top half' on to the new non purge bulb 'bottom half' ? That'd work I think and not much to go wrong with 'top half'. Think I'd ditch the purge bulb if new was the only option. But just fix the old carb, such a waste and expense to bin it.

A nice tell-tale, if you are prepared to do a bit of disassembly, is to drip some Redex into the accelerator piston hole behind the throttle shaft and see if you can suck it into the hi speed circuit. I tend to blank off the drillings in the metering chamber with blutack, remove hi speed screw and suck through there via soft tube. Any time you see red coming through the carb you know the accelerator piston seal is leaking.

No worries, pleased to be able to help

And so it starts......

Thanks for posting your findings and well done in doing the comparison between good and bad carbs, you have some certainty there. So, these valves can go wrong in a range from the working parts 'just get stuck' through to parts completely missing. The latter is often the result of high pressure air being blasted through the adjuster screw holes. There's a chance you can resurrect a 'just stuck' valve with carb cleaner, petrol, etc or ultra-sonic cleaning - basically you are just freeing up a tiny disk that 'floats' in the valve. Remove the low speed screw to access.... start with low pressures and progress, not much to loose at this point 😈 😨

Ok, I hadnt realised that, apologies. The point about the purge bulb pulling in air is still valid - it shouldnt do that. As stated before either hose fit on the purge bulb fittings is loose or the bulb itself is leaking. Always worth fixing things like this before they create a problem or symptoms you don't understand. ...

I'm confused by your experiment and statement that its not sucking fuel. I see fuel and air bubbles in the return line. So it must be sucking some fuel through the carb, no ? I don't see any air bubbles in the line between carb and purge bulb, is that all fuel? Edit: Looks like 100% fuel in the line between carb and purge bulb. I agree with Openspaceman, you have an air leak around the purge bulb, might just be a loose fitting hose on purge bulb, or a cracked leg on the purge bulb....

So you've got 2 fuel circuits in the carb, a low speed and a high speed. Low speed circuit is fed via the bung in your blue circle and there is a little flap check valve on t'side. High speed circuit is fed via the small hole below the main jet / check valve assy. If you have a piece of small dia hose, preferably soft silicone, you can hold one end over the entry hole and blow / suck to confirm the check valve operation. Adjustment screws need to be NOT bottomed out. Low speed circuit will flow a lot less than the high circuit....