Heteractis

That's the puppy..!! I have that exact one. Yes I see your point. Also, could it be that this particular saw needs a lower ratio, say 40:1 or something. It has never really smoked blue all that much......a slight haze but never an obvious blue of burning oil. I did wonder if a measuring jug and a syringe would be better for future use?

Just another thought, if the exhaust muffler doesn't seal very well could that cause problems..?

The fuel was maybe a week old from mixing at most but no, I cant guarantee the mix. A friend of mine has been helping me with the chainsaw work as he is a former aborist so I would like to think he would get it right but you never know! We have been using a 1 litre mixing bottle with lines to identify the correct ratio, 20:1,40:1,50:1 etc so you fill with petrol up to the 1 litre line then add oil up to the 50:1 line. We have been using this method for other chainsaws and strimmers etc. with no issue so far. Yes I should have changed the fuel but to be honest I hadn't even considered it a factor until now. I was speaking to our mechanic at work and he said there are only two ways to ruin a 2 stroke, not enough oil or revving too high so after he said that I thought about the fuel mix and the carb tuning. I suppose it could have been the carb tuning that did it but that seemed pretty good, finally settings were L = 3/4 turn anti clockwise, H - 1 1/2 turns anti clockwise. Idle was good and starting first pull. 4 stroking at WOT and cleaning in the cut with a slight 4 stroking. So the pressure test, do I remove the carb for this but keep the inlet bellows with impulse line attached and block that off? That would make sense.

I did wonder about re building it without some sort of pressure test but assumed (hoped..!!) that the broken bits I had found would sort it. I am not sure if it is worth investing any more money in this one or sell as is and get a cheap Chinese one for what I need to do. The wife and I are building a house and I only have the chainsaw to cut up all the logs we have after the tree surgeon took most of the trees down for us. I do have an awful lot of wood to get through mind, approx. 30 Tons at last count! Looking at it now, the first piston is probably salvageable so maybe just a new ring would do once I find the root cause. I am wondering about the fuel mix too as I used the same tank of fuel for both knackered pistons so it may well be there wasn't enough oil in the mix - a friend of mine did most of the mixing so I couldn't be sure it wasn't a bad mix. I didn't replace the fuel line (the one from the tank into the carb) so I may as well change this as I have enough fuel line left over. The impulse line looked fine but I changed it anyway. I maybe able to put the kit together for the test as we have a full mechanics workshop at work, presumably I remove the air filter and plug the carb inlet and plug the exhaust outlet and pressurise through the spark plug hole? Watch for the pressure to drop and check for bubbles with some soapy water? Maybe I should just cut my loses and give it to you to fix Spud..!! Thanks,

Many thanks for everyone's help so far but sadly the saw is still not very well... So I replace the piston and ring, the carb bellows, the flywheel (that I broke...) and put a new section of hose on the impulse line just encase. I couldn't find the full assy of the carb bellows with the new metal clamp but the one I have seemed pretty tight so carried on as it is. Gave it a clean and set the carb to 1 turn out on both L and H. Got it started no problems, compression was excellent (didn't measure it but much harder to pull over). Tuned the carb as per the manual and various posts, all went well. Saw starting on first pull every time from cold or hot. Used it at the weekend for the first time over the weekend to level off some stumps, got through 2 stumps and it needed a refuel. Put new mix in it (50:1 using mixing bottle) and it wouldn't start. Took spark plug off and it looked wet so assumed it was flooded. Took spark plug off, turned it upside down and gave it 30 or so pulls and left it over the weekend to 'dry out'. Tried it today and still wouldn't start so thought I would take it apart to dry it off, looked through the exhaust port and the piston and ring are fried again, worse than before. Strangely it feels like the compression is still good but the ring is stuck in the piston so it is knackered. So tempted to sell the bloody thing and let someone else faf with it! I only need it for some logging for firewood! Anyway, I am assuming there must be an air leak that I haven't found. Could someone point me in the direction of a guide for leak testing? Even if I sell it, I would rather sell a working saw than a crap one! Thanks,

From the pdf, it is the small rubber cylinder at the bottom of the intake below that is split around the join, item 13 on the carb ass drawing. I have the plastic clamp so this could be a leak point that has gone unnoticed. Also I notice I don't have the air filter clip, item 5, so the air filter is very loose. I will check the impulse line tomorrow. My next question is where do I get the parts from? Most places say out of stock or come from Hong Kong or the US? Thanks

I am not sure what year it was manufactured but it has a black plaque on it stating Husqvarna 346XP, then a number 965 41 02-00 then 00 4400516. I guess part of this is the serial number? New piston arrived today. Whilst putting it all back together I noticed the small rubber nipple section of the carb bellows (the rubber section that joins the carb to the cylinder) has a split right across the top section so would this cause the problems that I have had so far? If it is a problem where can I get a new one, apart from Hong Kong or the US..??! Thanks, Ben

No I haven't checked why it was low. Once I pulled the cylinder I figured it was because of the scored piston and ring? The ring isn't really bad but has got slight indents on it as has the piston. As it isn't too bad I assumed that is why I can get compression but only after 15+ pulls instead of only 6 pulls? I have bought the 42mm meteor piston kit and will wet and dry the cylinder. I have adjusted the carb back to factory settings (both fully in and 1 turn anti clockwise) but I am concerned about air leaks just encase. I did manage to chip one of the teeth off the flywheel whilst 'fixing' it so guess I will need to replace this too!

Is it easy to test for air leaks? I assume I need to bung certain 'bits' and pressurise through spark plug hole? I would have thought it would be better (more power...!) with the bigger bore?? Thanks

Many thanks for the replies, so I guess it isn't possible to just bolt in a 44mm kit then? The cylinder isn't too bad I think, as I said it does get compression but only after a good few pulls. Maybe a quick hone would be enough, I will check out the section as mentioned by Spud. I think the reason it failed is because we tinkered with the carb - I checked through the exhaust port for scoring only a few weeks back, just before I serviced it and then had the carb 'tuned', and there wasn't any then. Assuming I can get the cylinder sorted then I assume I can just buy the 42mm Meteor piston set off flea bay? Thanks guys

It's definitely 41.7mm, piston and cylinder measured 3 times. I assumed the 44mm was the old one and the 44.3mm the new one but clearly there is a 42mm as well! Can I just fit 44/44.3mm kit as can't find any 42mm for cheap money? thanks

Hi everyone, New to the forum, joined as I am a bit confused... I bought a second hand 346xp a few years back and after using it a fair bit the last few months it has started to play up so I gave it a full service and tuned the carb. After a few uses it started to play up again. Checked compression and got 125 psi but only after 10 to 15 pulls, 3-4 pulls gave very little. Stripped the cylinder and could see the piston and cylinder bore was scored. Checked on ebay etc. for repair kit and found either 44mm or 44.3mm kits so thought I had better measure what it has now only to find cylinder bore and piston both measure 41.7mm....?? Why would anyone fit a smaller piston and where did it come from...?! Seems really odd to me. Is this a standard thing to do? I haven'tffound anything useful on the Webso thought iI would try here. I assume I can just buy the 44.3mm kit, fit it and get the saw working like it should have always been? Any advise greatly appreciated, its the older 346xp the older one. Thanks Ben