bmp01

27 minutes ago, Macpherson said:

Hi, Just bought a spare Schott Robax glass by Calfire for my Morso on Ebay, a bit smaller than yours but that's what I last fitted when I broke mine some years ago and It's been fine....I doubt they'd sell any if they couldn't be fitted.

 

The last time mine broke [ carelessness ] I made a temporary  replacement with a piece of sheet steel  so I could still use the fire...also handy to have lying around if needed, cheers.

Nice one, thanks for that. 

The steel sheet thing,  yeah, i had that thought - comforting to realise I could get it working if need be.

Cheers, 

Chaps,

Well, I've darn gone and busted the glass in the stove..... lack of maintenance I reckon, not changed the sealing rope in 15 years and now I'm gonna pay for it.

So, it's a Stovax Huntingdon 35, glass is 390 wide by 305 tall, with quite a pronounced curve to the top edge. 

-Direct from manufacturer is 80 pounds plus delivery and is on back order.

-Supplied by Calfire, supposed to be Schott Robax material, is 40 pounds.

Sounds like a no brainer until you look at glass thickness,  Stovax is 5mm thick Schott Robax 4mm.

Thoughts, anyone had direct experience of replacing stove glass, where to buy etc. Also is it worth polishing the edges to get rid of 'crack here' nasty finishes?

Thanks, 

bmp01

Here's a post taken from the above thread regarding throttle linkage operation that might be useful to your our your mechsnically minded friend. ....

"Its a weird setup on these... the link is made to twist when you pull the trigger, the link is bent into a shape so that it acts as a cam which pushes on the carb lever. Twisting the link can take out play....

The wire link wears, the nylon block on the carburettor arm wears and the throttle rod can become dislodged from its location in the handle, then you only get half throttle movement.

My favourite hate is the cover for the throttle trigger with its protruding piece of plastic that keeps the linkage located in the handle - it's often broken off during reassembled. Result is notchy, half throttle movement. There have been several threads on here about this, new cover fixes the problem until the next time its taken apart and subsequently broken....."

To reiterate: a small twist of the throttle rod can take out the play in the mechanism.

Read this thread on another 211 doing the same,  read it again ....

https://arbtalk.co.uk/forums/topic/118620-stihl-ms211c-problem-with-power-in-the-cut/

And note the only thing that moved this on to something that people could understand and offer sensibIe advice about was posting a video of the saw misbehaving. Took several requests for a video there, guess it'll be the same here.

What is your location ?

Divots in the cylinder surface are one thing; bumps on the running surface are another kettle of fish entirely. Some of that damage is going to cause a few bumps for the piston and rings to run over.

I'd be surprised if you could hone it round without going through the bore coating.

In the first post you said "I have another cylinder, but that looks buggered on the lips of the ports" does that damage match the damage on the piston?

It's quite surprising there is no damage to the crankcase internals (if something got ingested by the engine).

Still,  looks like it'll go back together ok, agree with new piston ...

Meteor piston rings are Caber rings I believe, no problems there. You don't get a gudgeon pin bearing in the Meteor kit so yes, Stihl for that. And Stihl for the clips, cheap insurance.

That piston was running in that cylinder you say. ... But my money says that piston wasn't running in that cylinder when it got damaged, how can the piston have got repetitive impact damage and the cylinder get away no damage?

So what's this other cylinder, where did it come from ?

Reuse the cylinder with a bit of glaze busting and go for a new piston for peace of mind.

One of these guess the saw games,  first one to get it right pays the postage on the double bagger and gets a heap to sort out?

26 minutes ago, spudulike said:

When I get a 395 in I will do my patent method of getting the timing right and send you a pic along with the method of getting there. Just getting a shed load of 365XP Xtorqs in at the moment for conversion...and a brand new MK2 550XP.

That would be very much appreciated, hopefully it'll confirm where I'm at. ...

Clean machine eh, someone's spoiling you !

Thank you mister.

12 hours ago, Toad said:

I was having a little think about chain speeds in relation to my initial question about going with a .325 or a 3/8 chain over the last few days and sat down last night to work them out. 

 

Basing the calculations on the quoted max power engine speed of 9600rpm

 

A .325 chain with a 7 tooth rim has a chain speed of 18.49m/s

A .325 chain with an 8 tooth rim has a chain speed of 21.13m/s

A 3/8 chain with a 7 tooth rim has a chain speed of 21.34m/s

A 3/8 chain with an 8 tooth rim has a chain speed of 24.38m/s

Thanks for that eye opener, had blindly believed chain speed was function of engine speed and no. of teeth on sprocket. But now  you come to mention it .... 

Time for a bit of an update after running the saw today. This is first run since crank seal replacement and frigging with ignition timing after shearing the flywheel key (weather and access to field).

Things I've learnt:

Coil is unlimited as far as I can tell,  I saw 13250pm on the tacho once while settting the high speed.

Coil has no spark advance curve, constant tIming above idle speed.

Piston stop method of finding TDC gave me exactly the same result as using a piece of wire in the exhaust port - but it is simpler, less juggling.

Sadly I didn't get to check ignition timing before stripping the key out the flywheel. My best estimate of standard ignition timing is 19 degs BTDC.

I've advanced timing to  25 degs BTDC, engine seems quite happy,  no nasty noises or signs of impending doom. It has had 4 tanks through it today whilst milling oak, 28" bar with 22.5" max cut, (need longer bar...). Engine runs pretty strong, I'd like to think a little stronger than before but no hard evidence to support this.

Starting is more precarious,  starter rope was ripped from my hands half a dozen times; it doesnt seem quite as willing to start.

And that's about it,  I'll stick with the 25 degs of advance for now, the starting issues being the limiting factor for me. 

2 hours ago, John Rainford said:

 

When I had finished the single practice cut, and put the saw back on the bench with the shroud off, it was smoking quite a lot for a minute or two, it was obviously very hot.

Should I check the L screw, or leave it where it is?

Err yeah, its hot because there are twice as many bangs going on inside the cylinder when its 2 stroking rather than 4 stroking. And as you're reving the engine a good deal faster than before thats probably another 50 %. So maybe 3 times the heat input. Smoke will be the acumulation of oils (from rebuild and chain oil) burning off, probably less smoke next time.

Proper chain sharpening = faster cutting.

As Stubby says, get a sharpening guide, you will thank him once you've tried a sharp chain. It can't be emphasised enough the benefit of a sharp chain with correct cutting angles. The saw will stop bouncing about, you won't need to push on the bar to get it to cut, there will be less wear and tear on you and the saw. 

The key to it is the 'Top plate angle'. To get that angle right you need to have the round file at exactly the right height relative to the top of the tooth, (which the guide does for you). 4.0 or 4.5 files will make a small or no difference if the heights wrong.  Have a look at 'chainsawbars' sharpening here:

https://www.chainsawbars.co.uk/chain-sharpening/

12 minutes ago, spudulike said:

We may sort this before 2021....hopefully!

Maybe.  Have you got a walk through for changing the oil pump just in case? Hopefully just chain tension - couldn't see any blueing on the bar. But slightly intrigued by the tops of some of the teeth which did have a bit of colour.

That saw's not going to know what's hit it when it runs right,  probably grenade itself in panic (well, lets hope not).

Picture paints a thousand words, video even better.

In addiion to whats been said it looks like by the end of your demo the saw wouldnt reach 'high' revs out of the cut... it started out reving piss poorly but by the end the engine is labouring so badly it hardly has enough power to turn the chain even when its not cutting. I could be wrong, cant tell what you are doing with the throttle but the sound says its trying but can't do it - like the chain brake is part locked on, or the chain in is exceptionally tight. Just look how quick the chain comes to a halt,  it's almost locked up... 

If you repeat that exercise and turn the engine off, can you turn the chain by hand? Hot is it?

I totally agree with Spuds view but I'd say you've got some sort of chain or chain brake issue too.

Oh and the choke mechanism on these is on a par with the thottle linkage.... With age they jam and/or break.

13 hours ago, spudulike said:

......... throttle rod is bent or there is wear in the linkages.

Its a weird setup on these... the link is made to twist when you pull the trigger, the link is bent into a shape so that it acts as a cam which pushes on the carb lever. Twisting the link can take out play....

The wire link wears, the nylon block on the carburettor arm wears and the throttle rod can become dislodged from its location in the handle, then you only get half throttle movement.

My favourite hate is the cover for the throttle trigger with its protruding piece of plastic that keeps the linkage located in the handle - it's often broken off during reassembled. Result is notchy, half throttle movement. There have been several threads on here about this, new cover fixes the problem until the next time its taken apart and subsequently broken.....

Chain will start to run dependant on engine speed (so not directly related to throttle position). Presumably you are comparing with the newer saw ? Are you saying there is more movement in throttle trigger before the saw responds (wear in the throttle linkage)? Or you need more engine speed before the chain moves (possible clutch issue) ?

Either get agreement or wait until your brother is not watching then borrow the complete carb off his saw and try it on yours ! Taking known good parts and swapping them onto your saw is a sound way to diagnose issues. Complete clutch assy ought to be right up there to try as well.

Hope that video makes an appearance soon, Feburary is looming...

I can't see any pictures,  just minture no entry symbols ??? 

If all the parts  look ok, could it be the inside of the drum is oil or grease coated ? Too much grease on the clutch bearing ? Oil pump leaking?

How long have you been sharpening chains, have you got the raker depth correct (not too deep)?  Picture of the saw chips ? (But this type of problem would cause the drum to over heat. ... and drum isn't blue (hot) so...)

3 hours ago, John Rainford said:

The sprocket has two grooves on each arm, which have been cut in to it to a depth varying between 0.5mm and 1mm 

Those 2 grooves are in the OD of each tooth. The chain is driven on the face of the tooth, you will see a singIe wear mark on each tooth face - or with extreme wear a slot cut through each tooth (cuts the tooth more or less in half)....

One in the attached picture is worn but would still drive the chain. 

1 hour ago, peatff said:

 

What kind of carb is that ? Needles and float bowls are for bikes and wouldn't work upside down in a saw situation. Metering valve would give different problems straight from the off so it sounds like a fuel starvation thing.

Bog std Walbro or Zama carb I'd expect.

Assuming you start the saw from cold there is unlikely to be much pressure in the fuel tank,  you reply on the pump in the carb to deliver fuel to the metered side of the carb. This is controlled by the metering diaphragm in conjunction with the Needle Valve, ok call it a metering valve if you like. That's all pretty low pressure.

With running (think vibration) and heat you often get a build up of pressure in the tank (depending on breather type). If the needle valve were a bit suspect it mght not seal adequately.

Breather types - modern breathers are one way valves,  allow air in, don't allow fuel vapour out and cause pressure build up in tank.  Old breathers like 023 were a hose at the top of the tank with a grub screw (or pair of) in the pipe with a tiny drilling through - allow air flow in either direction. Not sure what version the 230 is. 

But anyway, fuel starvation is most likely, breather or otherwise.

As you say - an engine spluttering to a stop is likely to be fuel issue, after 5 mins tank vent strong possibility. When it stops,  have you removed the tank filler cap and tried to restart it? You might even loosen the filter cap before then as it starts to cough and splutter, does it recover? The 5 minute time would vary dependent on amount of fuel in the tank. Does the 230 still have that vent pipe with 2 grub screws in it ? Easy fix if so.

But it could also be the other way around,  building up pressure in the tank, flooding the carb/engine if the needle valve in the carb isn't closing at pressure, less likely but possible.

Let us know how you get on. 

17 hours ago, topchippyles said:

Saw/bar and mills for £300 + delivery as just not used,Bar cost £250 on its own and chain is still good 

I'd be interested in the bar/chain and winch? Might take the lot if you don't want to split. Whats on offer? Have to got pictures or details ? New thread time?

Thanks. 

5 hours ago, John Rainford said:

Thanks for your info spud. Wise words from an expert as usual. The compression test is obviously a must and your line about inferior parts resonated as well. So I will take your advice and keep my original parts until the culprit is found. The JB Weld gasket sealer is a rubbery type substance which says that it is high temp, fuel and oil resistant, so maybe that was okay. In answer to your questions.

1. The chain starts to cut and will go in to the wood a couple of centimetres. At this point the chain tends to stop running, but the engine doesn't die, it still sounds as though its operating well.

2.  The chain does not continue to run at high speed. Although the engine is running and sounds good, the chain stops moving in the cut. If I lift the saw away from the cut, the chain will start to run again.

3. The saw revs high in the cut, the chain slows down and then stops altogether, although the engine is still at high revs. 

John - regarding compression test,  in your previous thread you confirmed - the crude hang it from the starter cord test ....the saw dropped and nearly stopped at each compression stroke. Ok, its not precise but it confirmed compression isn't too bad.

I think Spud was offering multiple choice type questions, but nevertheless you're one step further on. Got any pictures of the clutch drum? 

49 minutes ago, NFG said:

"The saw revs high in the cut, the chain slows down and then stops altogether, although the engine is still at high revs.  "

 

Would that be the clutch slipping then? would have thought it would be smoking though holding revs.

Sounds like it or the sprocket is so completely trashed the chain is slipping over (or through) the teeth. Either way it doesnt sound like an engine problem.

Open fires win on appearance.

Stoves win as a means of heating a room because they only need to draw the right amount of air for the fire to burn. Compare that to the open fire that has a chimney that is also open to the room. The point here - once the chimney is hot it can move (draw) huge amounts of air from the room and that air has to be replaced from somewhere, usually from outside. 

By opening the fire door (or not having the glass in the door) you are converting your stove to something like an open fire because you've allowed as much air up the chimney as it can suck through the big opening.

Ceramic glass is used in stove doors. It's a special high temperature glass, available as cut to shape glass for common stoves but can also be cut to a template shape if need be. Quite expensive unfortunately.

Edit - I used the term 'Mica glass' which was wrong, Mica sheets are a different thing. Looks very thin and weak compared to the stove glass. 

9 minutes ago, htb said:

Steve would that be the same as base of barrel machined and base gasket thinner, so for a given thickness of spacer stop the crank would be in a slightly different position from modded to standard?. Correct me if I am wrong.

It would be different for an engine that has 20 thou squish compared to a saw that has 40 thou of squish. Squish being the distance from top of piston to underside of chamber at TDC. You'd have to know what the squish was in ech case and then move the piston down a further equal amount on both set ups. Halfway down the stroke the squish gets less signifcant but its still there in the detail.