spudulike

What happened...in the 80s you could get drinks for a night out and a Chinese on the way home for £20.

Sounds like lack of fuel, check the gauze strainer on the pump diaphragm side of the carb. Do take it out to inspect as they can get blocked by a fine scum. If that is OK, try giving the H&L screws 1/2 a turn anticlockwise and that should get the thing running. These saws are usually set on the lean side on manufacturing to save them failing the emissions checks and as the saw gets a bit older, it stops the things revving out.

Yup, his spelling is suspect at best and utter shyte on the other end of the scale. I would never mention such a faux pas🤔👍

Not bad service or price on that, a bummer that they don't do coffee and doughnuts though! Hopefully it is all working and good now.

Ah, the symptoms of excess fuel and not needing choke on cold start like you have are generally contributed to the needle valve not sealing up correctly. This could be a hardened diaphragm, weak needle spring, worn needle or just a poorly adjusted needle arm. A full carb kit may well sort out the issues. Personally I would get one and fit it unless your local arb fixer offers coffee and doughnuts to all customers👍

Looks like Cherry and Plum to me, Apple is smoother and flaky. Agree on the third looking like apple and it does shed bark when older.

I usually turn the L screw in until I hit the high point just before dying and then turn it anticlockwise until I get the idle sounding slightly out of rhythm but 1/8 to 1/4 turn is probably good. The 372XPT can be a bit sensitive to idle speed, I think the ramp up on the coils ignition advance from starting low revs to idle speed wasn't the greatest.

You have pretty much answered your own question. The saw isn't fuelling correctly so you need to inspect the fuel system so we are talking fuel filter, fuel line (not split), the carb (diaphragms and gauze strainer) and the impulse line. The most common issue on an old saw is a split fuel line, clogged gauze strainer or hardened diaphragm. The only caveat to this is that a BIG air leak in the engine can stop fuel vapour being pulled in to the engine but is less likely.

Difficult to tell but your description of the engine not starting until stone cold could be that the engine has low compression and it is dropping off further when warm and making it hard to start. You can measure it with 150psi+ being OK, you can take the exhaust off and inspect the condition of the piston and when there, check the exhaust port isn't clogged with carbon. The cooling down thing can be a dodgy coil or the flywheel to coil gap being too large. You can regap the coil to flywheel with thin paper and this may get a weak spark back up to full tilt. Other than that, the fact the plug is wet may mean the needle valve is leaking letting through too much fuel and flooding the saw but can also mean the engine is just not firing on start up so very difficult to tell. A carb rebuild is my normal start but do check the spark by removing it, earthing the plug on the cylinder and pulling it over to test but make sure the plug is away from the plug hole as you can get some pretty spectacular flames from ignited fuel from the plug hole. In the carb, make sure the needle and spring are sealing correctly, the metering diaphragm is soft and flexible, the pump diaphragm isn't deformed and the flaps are not holed and finally that the gauze strainer isn't full of chip.

I think the coils are limited to 13,200 or thereabouts. My usual method was to tune low and build up revs to the point the tach just went loopy so the carb would be limiting at the same point the coil rev limiter cuts in. Your method may OK if you have the time to do cuts and plug chops to see what you have but I never had the luxury of time so the above gave me what I wanted...a reliable machine doing what it should.

The saw should be set to 13-13.5000 RPM. It may take more but setting tuned saws to near maximum of the manufacturers stated limits is what I always did. Not sure how you are tuning it but taching a saw in this way always ensures the same result.

Yes, all sounds about right. Generally those slider bearings fall apart from lack of grease and implode. There is a C clip that can come off and stop the drive, failure of the "non splined" bearing can stop the drive to the head plus one of those bearings is riveted to the shaft and failure of the rivet can cause lack of drive. Agree that the Stihl diagram is pretty confusing but if you look at it enough with the parts in front of you, it does make sense. The bearings have slots in them to ensure they locate in the large outer shaft correctly....yet another hoop to jump through.

When I was in the game, I appeared to be the only guy in the area that could rebuild these things. It started with one that I took apart in my garage with a mallet and bits shot everywhere so I had to sort out what every bit did and where it went. Once I had done that, it was relatively easy. You are missing one of those funny sliding bearings, you should have two with the splined internals and one with just a round inner. You also appear to be missing the round tube cover that sits on that splined shaft which is a bit baffling as it slides up the round slider bearing you have pictured. These are an acquired taste to rebuild but once you have done a few, it becomes much easier. Oh...you are also missing the fecking great springs that usually sit between the sliding bearings. It has been a while since I last did one.

The fellas in France so probably not.

PM me when you have the info.

If the muffler mod has been done correctly, good gains can be had from this small saw. Just tune it to rev out at around 13,000rpm and all is good. Stuart - is this saw one of the old ones? Look at the serial number above the recoil cover. If it is a sticker then I may have a fix, if it is a laser etched serial then it may just need a carb tune.

Difficult to say but if it was in my hands, I would check the maximum revs and if they were higher than they should be and the high screw is turned fully anti clockwise (I am assuming limit caps are in place) then it is most likely an air leak or an issue with the fuel system. Generally it is easier to check out the fuel system from the fuel filter, fuel line, tank breather and carb then doing a full vac/pressure test but if the fuel system is OK then you would need to test for an air leak and be prepared to sort this out if present and then resetting the carb to correct the maximum revs. Often you can tell an air leak is present from the effects on the low screw adjustment where you have to compensate for the extra air by richening the screws and turning down the idle screw.

BTW, if you are looking at fitting the old piston in this new cylinder, it looks like there is a big gouge above the exhaust port and, if so, you will need a complete new top end. It is unlikely the cylinder will show no damage after this sort of issue.

The ring pins should run either side of the inlet port and NOT the exhaust port. You should be able to see the marking on the original piston if the crown is lightly cleaned of carbon. Just look at what you did last time and do the opposite.

Very likely, I replaced very few when I was fixing up saws. The odd one was through years of use rather than much else. It is likely the pawl isn't extending outwards as it should when the handle is pulled.

Another village litter pick coming up soon, more vodi bottles in the ditches I am sure🙄

You put the piston in back to front, the arrow points towards the exhaust port, in your case, it is pointing upward towards the inlet port. All parts are OEM but the ring ends have caught in the exhaust port and smashed the piston up. A little knowledge is dangerous!!

I saw a YouTube vid of a McLaren engine rebuild where the oil pump shaft had failed and was surprised that the engine didn't just stop on a fault code rather than running until it seized. Your ECU should save the code and a decent OBD2 module and app may be enough to help you find the fault. My usual is the 2nd sensor on the CAT failing....got changing that one down to an art! The OBD2 does allow you to reset non safety warnings and will only come up again if the fault is still present. May just be a bit of shyte on a crank sensor or something like that.

Sanatogen and an Ibubrofen chaser may be tops with the elderly.

Yes L&S for OEM parts. Check the flywheel inner boss that the pawl contacts with, if it is badly worn or covered in crap.....possible cause. You can fit the double spring retainer and twin pawls as in the MS460 but tbh...it shouldn't be necessary. Double check that the pawl is extending fully when you pull the starter handle slowly....with the cover off otherwise you won't see it🙄