billpierce

9 hours ago, openspaceman said:

Does the gap change as the ring is moved up and down the bore?

Have not checked but will do so

Just answered my own question! Thanks for help so far! Piston skirt doesnt seem to rock much 

Well with the ring pushed square down the bore an inch I can fit the feeler gauge which says 100 on it through the smallest part of the gap and that's the biggest one I have. Think that means 1mm gap as its .05mm to 1mm guage so reckon that means worn right?

8 minutes ago, bmp01 said:

The plot thickens !

I have nothing to add regarding your question.

So it's definitely been apart before then,  what is the running spec of a 350, ie max speed, speed of max torque

Also, what is that piston? Ring looks very thick, or is it just the picture? 1.5 mm rings found in old pistons and aftermarket lower grade pistons are not good for speeds over 12 k. I would have expected a 346 piston, genuine or Meteor, to be using a 1.2mm ring. Wheres someone with Husky knowledge.... 

 

It's a mahle piston, perhaps it looks big in that pic, I didnt notice it as being that big before. Ring doesnt look over worn either tbh.

Any help appreciated. Shall I get a 350 piston?

Update on this troublesome 346. Got a new meteor piston today. Doesnt fit. Turns out it has a 350 pot and piston on it, so that's annoying. Is this a common swop? 

3 hours ago, gary112 said:

How many hours does a piece like that take Bill?

I'm really bad at keeping track but 4 to 5 days

Had wee commission to make this as a memorial for a book shop owner (shop called slightly foxed) in berwick. Few pics start to finish. Made the specs from some old chain links.

On 06/12/2020 at 08:49, bmp01 said:

Think you've done enough engines by to know what to look for, residue on piston ie combustion gases passing the rings never a good sign.  If the piston is unworn ie. still showing turning marks on the skirt and rings are unworn  maybe the ring grooves are choked up with crud ? Piston ring does some sealing on its own but it also needs the combustion gas to get on top AND behind the ring to force it onto the cylinder wall. Obviously if the ring groove is too tight (piston made wrong or clagged up) - then that doesn't happen.... result is blowby past the ring. Swaping in new piston is obvious solution.

 

Is the cylinder bore shiny ? Might be worth a gentle deglaze ?

 

As an aside, ever heard of ring groove porting? Several small drillings to get combustion gas to the back of ring. Drillings in top edge of ring groove only.

 

Thanks bmp! Going to swop pistons out

On 05/12/2020 at 19:48, spudulike said:

The Gunson gauge is one of the more reliable ones, I did keep blowing the schrader valves on modified saws so fitted a Presta one and it has lasted well. 

A decent 346 should have 170psi.

What was the end gap like? 7 thou is good, below 20 is OK, anything over and it is looking a bit iffy. 

Sometimes you have to tear it all down again and then build it up again to get to where you need to be.

Are there signs of it being over-fueled  such as a wet oily residue, black plug etc. 

The only time I have come across this sort of issue is with saws with excessive top end wear, the last one was an 020T that was doing exactly the same thing, couldn't get the revs above 12k even with the H screw turned in!

It is possible the HT cap is leaking down making the high revs miss or the carb having a leaking check valve or the coil being like your 361 one but that was a limited one.....weird one but my diagnosis head still comes back to engine wear.

Stick a new piston in it😉

Sorry seem to be missing posts dont know why. 

Have tried a 357 coil and swapped the carbs and still the same so piston swop next!

16 hours ago, peatff said:

MS 200 back handles used to be the wanted saw for carvers and always fetched good money, has it changed ?

Nah think they are still desirable just the last few I have sold (back handle 201 and back handle 200) did not really get any interest above £200.

I guess if I had a choice of new smaller echos or used 200 (especially if it was £300 ) for carving I know which way I'd lean

4 hours ago, spudulike said:

It is an easy one, there is something that is stopping the saw reaching peak revs - Circa 14700+ on this saw. All you have to do is find it! 

Electrical - you may be getting something stopping the coil doing what it should, is it a blue limited coil....probably not and none of the limited blue coils limit to 12Krpm. Perhaps there is arcing on the plug or cap or the kill wire/HT lead is touching earth or the coil is shot. In my experience, these arcing/shorting issues don't cause rev limiting issues,they stop the engine. A limited coil can blow the high speed section so an engine won't rev out, seen that on a 361 and a blower so it does happen but isn't common. You could try many of the coils off the 3 series saws just observing some may be limited so will send a tach all over the place once it hits the limiter. Check the HT lead with a multimeter and check connections at both ends, check the kill wire or just disconnect it. Check the coil gap.

Fuel - how is the saw running? Wet, oily, smokey black plug or is it lacking power, bogging, lacking power. If the carb is throwing in too much fuel, you will be getting a heavy fuel residue. It is possible you are getting far too much fuel or far too little. I would pressure check the fuel line, check the tank breather and also the HOLE that goes in to the carb elbow as I have seen two with the through hole not present! Check the gauze strainer - take it out and use a magnifying glass, get carb cleaner down the H and low screw, check the pump diaphragm, especially the pump flaps and pressure check the carb.

Mechanics - Check out the piston for the things BMP has mentioned, chack the compression, 150 is getting low on these saws, 170 is decent. Check the first hard pull. With the base gasket deleted, you should be 80-100psi - if this is much lower and you don't get up to almost max reading in 3-4 pulls, the engine isn't in good shape.

Check the bore and plating for wear and discoloration. Check the inlet manifold, especially the impulse nipple (Yes, I did say NIPPLE)....it often splits along the top or can get distorted if not fitted properly. Is the short impulse line fitted between the inlet clamp and the carb connector fitted correctly - just had this problem!! make sure the inlet manifold perforated inlet support sleeve is fitted.

Make sure the muffler isn't blocked - had one plugged with mud once!!!

I can't think of much more - I have just spent 4 hours on a 200 I had rebuilt that just wouldn't start. I had replaced the HT cable and was getting a big fat blue spark jumping 7mm so it was never going to be an HT problem was it......cock yes it was, after stripping it doing a full leak test, swapping carbs, coils, flywheels etc etc, I swapped the HT lead and bingo....the HT lead being screwed on had forced the copper strands deep in to the sheath making a bad connection - great spark in air, none under the 200psi compression the saw had!!

If you check all possible issues, the issue left, however improbable, is the culprit!

 

 

Thankyou for the thorough reply. Have done an awful lot of those things, but still more to do. Will let you know how I get on

Yes but.....what is the compression reading? Even OEM cylinders and pistons wear out. I have seen this before and bores can wear out. 
Is it the older 45cc machine as this was the older version.
I once had a 024 and it had compression of 180psi as I had dropped the base gasket, it would barely spin the chain and there was nothing on the handle - the inlet side of the bore had no plating left!
I would measure the compression or check the bore, the ring end gap and then the piston in the bore.

oh and get a 1/4 carving bar  not 3/8

klingspor fibre discs with the smaller white plastic  115mm backing pad is best combo, found the cheap discs wear out really fast

dont seem to get as strong money as the top handle versions. id say about £200 each if in really good condition

Has anyone had, used, or even have any info on these. Didn’t know if it would be a good option for a work truck. 

. OEM pot. Not had it off but piston isnt scored and comp is ok, will run and idle fine, just doesnt feel as zippy as it ought to ( this was bought by a friend and he wants me to fix it so no little of its history).

Sounds like its four stroking and just wants tuning up, but nowhere to go with the H screw!

Have changed sparkplug, coil, checked gap, new OEM carb innards and also tried new carb, and filter

Thay reminds me. Another vital clue is the hi revs dont go higher than 12k even with the h screw wound in, which blows my mind. Both carbs the same both original one with oem rebuild kit (have changed Welch plugs but did seal them with super glue but they looked fine) and cheap chinese test carb. I dont get that!

Yes, throttle is opening fully@sawchip

2 minutes ago, Sawchip said:

Is the throttle rod plastic end worn ?

my gad sir! that would be a sweet fix. will check, but think from memory it looked like the butterfly was opening right up

Got a funny one - 346 xpg older model. Wont rev up beyond about 12k, even with the bar off only makes 12.5/13k ( no sign of a limited coil kicking in). I have cleaned and changed carb internals, then replaced the carb with a new one, changed ignition coil and checked flywheel key, all ok. Replaced fuel filter, spark plug, fuel line appears nice and rubbery but havent changed. Impulse line is creating vac/pressure, but not visually inspected it. checked piston (appears in good order with good looking piston ring, no scoring).

Havent done a vac test as ain't really displaying symptoms of an air leak but probably what's next unless someone has any better ideas?

Thanks advance

Not really noticed increased battery life or cut speed tbh. It's a definately smoother cut, better suited to pruning. Found the clutch cover gets clogged alot quicker on 1/4 panther which is a serious pita, often needs clean out before battery is used. So swapped back to 3/8p for now which has resolved this

Not 100% sure but I have used plenty husky mount bars on various makita with out any issue

I know this has been asked many times before but there seems to be so much more choice now.
I don't climb every day and have always used the old Buckingham's with long spurs always tell myself after spending a day in them that I will replace.
I'm getting older and have tried shorter spurs in the past which I prefer and id like lighter and more comfort.
Which sort should I go for? Not too fussed on price as I know how important comfortable good spikes are.
Thanks