BaconBoy Posted June 3, 2012 Report Share Posted June 3, 2012 anybody give me a rough idea why a chainsaw wont run when put under load even though it starts first pull.seen one advertised spares/repairs on the local gumtree site(it's a husquvarna). thanks Quote Link to comment Share on other sites More sharing options...
Diceman Posted June 3, 2012 Report Share Posted June 3, 2012 knackered clutch? Quote Link to comment Share on other sites More sharing options...
ColinF Posted June 3, 2012 Report Share Posted June 3, 2012 Sounds like a fuel problem, blocked fuel or air filter, or the carb needs an overhaul Quote Link to comment Share on other sites More sharing options...
ack-ack Posted June 3, 2012 Report Share Posted June 3, 2012 Its a safety feature Quote Link to comment Share on other sites More sharing options...
Catweazle Posted June 3, 2012 Report Share Posted June 3, 2012 I'd guess at a blocked carburettor jet. Quote Link to comment Share on other sites More sharing options...
aga man Posted June 3, 2012 Report Share Posted June 3, 2012 Its a safety feature lol think colin is about right, usually fuel related Quote Link to comment Share on other sites More sharing options...
Livefast123 Posted June 3, 2012 Report Share Posted June 3, 2012 It's either the air or fuel filter are blocked, jets are blocked or somebody has attempted to fix it and messed up the mixture. I would guess that the mixture is far too lean so it just cuts under load rather than heavy smoking if rich. I would change the spark plug for good measure. Quote Link to comment Share on other sites More sharing options...
Diceman Posted June 3, 2012 Report Share Posted June 3, 2012 (edited) When you say under load, do you mean the engine or the chain? Edit to clarify, does it rev freely but stall when you try to cut something? Hard to say I guess as you don't have it yet but I would say if it starts and runs it shouldn't be too difficult / expensive to fix. Worth a gamble if the price is right and you are reasonably handy? Edited June 3, 2012 by Diceman Quote Link to comment Share on other sites More sharing options...
zx10mike Posted June 3, 2012 Report Share Posted June 3, 2012 there is a chap on e bay that overhalls carbs 25 quid pm me if you want his num.sounds more serious tho.if the clutch is knackered you normally cant stop it turning not the outher way. mike Quote Link to comment Share on other sites More sharing options...
Kes Posted June 4, 2012 Report Share Posted June 4, 2012 My last Stihl did that and it was fatal. Apparently the chrome lining on the bore had been scored and the piston, when cool , would allow the engine to start,. As it heated up, it lost power, like fuel starvation and eventually stopped, only to restart when cool. If you take the exhaust off and move the chain by hand you should see the condition of the bore. Its just as likely to be fuel or air filter. When did it last run? Unleaded is pretty poor after a long while in the tank. I'd give it a wide berth and pay a bit more. Quote Link to comment Share on other sites More sharing options...
Thedeerman Posted June 4, 2012 Report Share Posted June 4, 2012 I just bought a new husquvarna with 15" bar for £180. I was looking at secondhand but its not worth the headache when you can get one so cheap new. Managed to get a spare chain chucked into the deal too. Quote Link to comment Share on other sites More sharing options...
Gav912 Posted June 4, 2012 Report Share Posted June 4, 2012 When mine done that trick back in January it was the fuel hose at fault, just a small hole in it. Husqvarna's don't like being stood about for long periods, the diaphram in the carb can go porous as can the fuel hose in my case. Quote Link to comment Share on other sites More sharing options...
redtailhawk1 Posted June 4, 2012 Report Share Posted June 4, 2012 Mine did that then it would not start. Mixture too rich and worn piston and pot. Make sure you have enough oil in it. Good luck Quote Link to comment Share on other sites More sharing options...
hillmouse Posted June 5, 2012 Report Share Posted June 5, 2012 My money is on scored piston/bore. A classic Husqvarna fault and fits the symptoms perfectly. Starts fine from cold, runs OK and then quietly dies and won't start once warmed up. It will start, it will run and will rev like hell when you go to buy it. Once you put it to work it will drive you mad. Add the purchase price, frustration and wasted time, cost of new piston/bore and hassle and I would really just go and buy a new one. Made this mistake myself and bought a very tidy looking saw which drove me mad. Check air filter, fuel filter, plug gap/new plug, replace fuel, reset carb to factory settings. If that fails, see above. Quote Link to comment Share on other sites More sharing options...
redtailhawk1 Posted June 5, 2012 Report Share Posted June 5, 2012 My money is on scored piston/bore. A classic Husqvarna fault and fits the symptoms perfectly. Starts fine from cold, runs OK and then quietly dies and won't start once warmed up. It will start, it will run and will rev like hell when you go to buy it. Once you put it to work it will drive you mad. Add the purchase price, frustration and wasted time, cost of new piston/bore and hassle and I would really just go and buy a new one. Made this mistake myself and bought a very tidy looking saw which drove me mad. Check air filter, fuel filter, plug gap/new plug, replace fuel, reset carb to factory settings. If that fails, see above. I'm with you all the way. That's what happened to mine. Should have and need to buy a new one. Quote Link to comment Share on other sites More sharing options...
Conygree Posted June 5, 2012 Report Share Posted June 5, 2012 (edited) start with a new plug and clean the air filter - some guys never do. Could be jet setting, assuming the motor is ok - set the H screw to say 1 turn out and run the saw until warm, then with a screwdriver in the H screw & rev the saw right up and if a bit flat (4-stroking) turn the screw in a bit, or if it won't rev turn it out. It should get to a level where it runs freely - it will need to be set at max revs but that should give an indicator if the saw is ok and only minor probs. if you want somebody to repair your saw look on 'Arbtalk - chainsaw section' and put in a post for 'spud' he fixes alot of saws for guys at a fair price. Oh just remembered: check the exhaust muffler is not obstructed, had a small saw that lost all power - stripped the carb etc but it was just the exhaust carboned up. Edited June 5, 2012 by Conygree Quote Link to comment Share on other sites More sharing options...
BaconBoy Posted June 5, 2012 Author Report Share Posted June 5, 2012 thanks for all the help guys,but the advertiser hasn't got back to me yet Quote Link to comment Share on other sites More sharing options...
redtailhawk1 Posted June 5, 2012 Report Share Posted June 5, 2012 thanks for all the help guys,but the advertiser hasn't got back to me yet If that means your buying one? Then if I were you I would get a new one. I bought a second hand one and am sorry now. Quote Link to comment Share on other sites More sharing options...
al4x Posted June 6, 2012 Report Share Posted June 6, 2012 thanks for all the help guys,but the advertiser hasn't got back to me yet thats a good thing, broken saws just aren't worth buying they haven't been fixed for a reason usually despite the story. If you can change the piston etc then fine but to pay someone usually writes them off. I have to say I wouldn't ever buy a second hand saw as you just never know if its been run with a weak mixture. As said some of the small husqvarna hobby saws actually take one hell of a bashing I had a 136 for about 8 years doing plenty of clearance on the shoot and home and doing each years logs in the process which was no mean feat as we do burn a few. Just look after them and keep the chain sharp and thats about it run till they break. That one is in the shed doing exactly your symptoms so if you want a freebie to waste your time and money on let me know Quote Link to comment Share on other sites More sharing options...
captainhastings Posted June 6, 2012 Report Share Posted June 6, 2012 Give the air filter a clean first then change the fuel filter you can hook it out the tank with a bit of wire as a rule and just push a replacement on at least that is how they used too be Quote Link to comment Share on other sites More sharing options...
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