spudulike

A high idle speed can make the chain run as can the chain being too loose but if the springs are working properly, you shouldn't see that chain moving on anything than a fast idle.

The usual signs of clutch springs getting weak are a ring ping sound coming from the saw at idle which are the shoes hitting the clutch drum and also the chain pulsing forward when the saw is standing on idle. If you look at the clutch against a light, look at the springs - if you can see light between the spring coils then they are probably OK, if the coils are touching each other, they are past it. You can remove them by getting a small screwdriver under the hook and levering it off and using a piece of thin string doubled around the hook to extend them and get them back on.

Try the easy options first and then explore the more difficult ones if the easy ones don't cure it. It always helps to know the age and condition of the unit.

What happened to the OP and his issues??? Any luck sorting the low compression?

I use two pneumatic rattlers, the only real risk tends to be that the flywheel can come loose when rattling the clutch off the other side of the engine. This is mostly on MS150s as the flywheels are not REALLY cranked up hard like some so I usually avoid guns on small engines if the flywheel is in place.....many say they haven't found the same but I have seen it, great bits of kit in many applications but take care with smaller saws especially if the flywheel has come off recently.

Red Stihl is just a lower spec oil, HP Super is probably the best choice £££ to performance wise. Another thumbs up for Rowena, excellent service which is typically one day from order to delivery. I do always try to bulk up my orders so they are worth processing but more difficult when ordering a single carb kit.

Most likely carb issues, check the gauze strainer by pulling it out of the carb and inspecting with a magnifying glass. It is easy to think they are clean when in situ....learnt the hard way on that......or just swap it out! Pump diaphragms can perforate so check that in a similar way. Try starting it without the head on and see if it is OK like that, a tight cutting head or faulty oiler can cause bogging symptoms. Other than that, these four stroke units often lag on the throttle if the accelerator pump is worn. It is a bit difficult to change for the uninitiated but had this on one KM100 I worked on, very flat on the throttle response and fitting a new pump cured it! Try the easy things first!

I think you need to calm down a bit and agree.....simplest engine on Gods earth! The rest of it is a bit iffy.

My chart says C1Q S121 or 122 is 1.5 turns on the L and H is 1 turn. The MS181 has changed over the years, the initial saw was non Strato, yours is the later model. If you are using the handbook that came with the saw, go with that otherwise use my setting if you have the S121B or 122B carb

These saws tend to leak oil from the rubber pipe underneath the saw where the oil tank connects the oil pump. The smoke could be oil burning off the clutch drum. It is worth checking the clutch springs, if they are slack, they can contact the drum and produce heat. Unlikely for anything to fly off when revved as it is an inboard clutch but....there is always a first time! The carb - probably the most common issues are crap in the gauze strainer , perforated or distorted pumping diaphragm, weak needle valve spring and hardened metering diaphragm. Your carb has had the limiters removed, make sure it is set correctly - 1&1/2 on the H screw and 1 turn on the L screw.

If compression drops significantly when hot, the saw will lack any grunt, torque, mojo.....poor compression hot maybe wear to the piston, ring/s, or bore, it is possible the saw has nipped but the ring is loose enough to seal but is scored......etc I do tend to use the starter handle to tell what the compression is like and use the gauge if it feels poor. Ergo start mechanisms do mislead at times making a saw feel low compression when it is really OK and some saws often feel low but when measured are fine - just the size of the pulley used. Many times a saw comes in for a rebuild and a compression reading cold is all you can do as the saw isn't running and it does give you an idea of the state of the saw. and the type of work needed. A cold compression check does give you an idea of what the engine gets to start it especially on the first pull. I generally use it more if I have a bad starter, saws that feel a bit low after a rebuild and ported kit.....everyone has their own methods and ways of gaining info from kit being repaired or modified.

Not much colour on it to judge but it looks like the end electrode is going tan which is good. Use it a bit more and expect the outer parts of the plug to go black and the inner part to be beige/tan!

Interesting on how others work. I measure compression cold and if I then feel it is suspect or feels less than I have measured when cranking, measure again hot so I get a comparison of the drop when hot. One of the most telling parts of the compression test is the measurement after the first pull, if it comes up high on the first pull, it generally shows an engine in good fettle.

The autotune module has no facility for adjustment like you probably think it does, no silver bullets are there just a basic diagnostic and firmware upgrade. If the machine is over revving, has a fast idle etc then the first thing I would check is that the throttle is closing fully. If you can, start the machine and try pushing the throttle arm on the carb completely shut, if this snaps the revs down as it should then you have a throttle cable issue - chaffed, poorly sited, control handle moved in to the wrong position, carb throttle return spring broken or the carb throttle shaft binding (possible if stored in a damp area or cleaned with water) etc. If the carb throttle is closing exactly as it should then the next most likely issue is a big air leak - impulse line, inlet manifold or something like that but is less likely on a later machine.

The MS880/088 will thump like a goodun when revved flat out with no load, it should clear up under load in the cut - just check that the plug is a dark tan to light tan around the central electrode, white is bad and graphite grey is terminal. The MS880 revs to 11000 or 11500rpm depending on carb, the 088 revs to 12000 and the ones I have ported have picked up faster and been more livelier. The MS880 won't sound like a small saw, they rev slower and produce a lot of low down grunt. If it isn't starting well, try richening up the L screw, this may help and expect to increase the idle speed a little as a side effect of the carb adjustment.

They do, usually pieces of wood chip get pummeled in to tiny pieces of wood pulp and these gather in the gauze strainer, it happens, fuel filters are not infallible!

Dirty boy!!!!

If the pressure vacuum check included the manifold and impulse line and a carb swap didn't give an improvement then you really have an issue unless both carbs are shot. The only thing left is the throttle linkage as if the saw isn't leaking air and the throttle valve is completely closed, it is pretty much impossible to get a fast idle speed! A split fuel line will give you bogging and is unlikely to give a fast idle. Are you sure you reconnected the impulse line?

Yup, I know that, we will see who is still remembered in 30 years and that will prove a point.

Typical of some of the ijuts I have had to deal with on eBay that have no comprehension of what an Auction is.....you bid, you buy, you pay.....simple, it isn't a lifestyle choice, you aren't in Primark!!! Joe is a good bloke, he may have been a bit premature but knowing him, he will have it!

There is a lot of this going on, been waiting for a MS200T top end for a while now, nothing I can do about it, it is what it is and will fit it when it lands. Not making life easy but can't change it so don't worry about it! I duck and dive, get inventive on priorities....not much else you can do!

See if you can pay the duty up front so the consignment doesn't get hooked up by the customs. That way you know what you are in for. Look for GSP or Global Shipping Programme or look at 20% VAT on top of the local duty and the handling charge!

Cylinder With Piston 42 mm for Stihl 024, MS240 - 1121 020 1212 | L&S Engineers WWW.LSENGINEERS.CO.UK Cylinder with piston 42 mm Genuine Stihl Part OEM Part No. 1121 020 1212 Suitable for the following Stihl...

If you had purchased a TT-20K, you would have slapped in another PP3 and off you go for another 3 years!

Blimey!