Thread: 4 chainsaws 4 problems.

Hi Carl

You need to buy a decent brand of Chainsaw like a Jonsered. My brother in law and I have had between us seven of them all different models and never had a moments down time ever.

You've been watching too many TV ads telling you how good they are. "NOT"

Jonsered don't have to advertise their machines. Everyone knows how good they are.

o yer.

the bloke next door has a jonsern and it cant even cut threw 2 125mm cca logs at once. it is twice the weight of my 026 witch can run a 20" bar in the mill no problems.

love the disclaimer barry.but weisy has got a problem with sthil not the jonserod. and yes i have heard they are a very good saw, but don't have a big foothold in oz. sorry weisy i cant help. all i do is pull them down ,clean every thing ,new mix of oil and if it doesn't work of to the dealer cheers

yer the dealer

sent the 170 in to get the oiler working again and cost us $100 all they did was replace the hose.

allthow they did sharpen it aswell but it didnt seem like it. it wouldnt cut holes in copers logs.

#1 Oil to the sump. Saws tend to have a diaphragm pump to convert seconary compression pulses from the crankcase to a positive oil feed for the chain and bar. If the seals or diaphragm fail, it will suck the oil into the sump instead of pumping it to the chain. Does the oil get from the tank to under the muffler in 3 minutes resting or 3 minutes running?, If its 3 mins running, its probably getting through diaphragm to crankcase, then pushed through the pot and coming through the exhaust. If its a two piece type muffler check inside to see if its oil wet.

#2 Hot run, won't stop. Its running extremely lean, most likely because its getting air into the intake from a leak after the carby. To stop, choking might help if the throttle hold/choke interlock will allow it. Even if it doesn't stop it, the richer mixture will help to control overheating and overrevving. Worth a try to check out the interlock when stopped and to see if it helps. Most likely has a dodgy gasket btwn the carb and engine, the crankcase halves, or the case and pot, or something is warped and leaking. Other possibility would be crank seals.

#3 angle sensitivity below full tank. From model aircraft days, this is most likely to be the pickup hose in the tank. Two possibilities, it is kinked and folding back on itself so the clunk/fillter cannot move enough to stay in fuel to the end of tank, and ends up sucking air prematurely. Alternatively, pickup tube in tank has a leak along its length. The leak is not an issue while immersed in fuel with a full tank, but sucks air once the fuel level falls below the leak. Changing operating angle covers the leak and corrects fuel draw.

I wouln't run any of them till they are fixed as the is potential to do serious damage internally in each case.

Hey Carl,

sorry mate I don't want any of your probs I had an issue with the 372, farting and not having any torque when put into a cut - turned out to be my metal fuel can. It was creating condensation over colder nights and hotter days, which dumped water into the fuel. After chucking the metal can and using the compressor to 'blow dry' the fuel tank on the 372, she hasn't given me that prob anymore. Did have another prob with not getting up to top revs when cutting, but that has been sorted with a little turn of top end adjustment screw.

Still running after the plg lead has been disconnedted -sheese, that is nasty, I'd definately be getting her in the shop ASAP.

THe fuel sounds, as said, like a small hole in the pick-up line from the tank - how old is th esaw and has this ever been replaced. Our Husky dealer once mentioned, this is a common problem due to vibration, time and fuel, the hose only needs a small 'invisible' hole to suck some air when you are part way through a tank and you have the problem. On mine the fuel line is about $15 I think - a cheap way of eliminating something even if it doesn't end up being the cause???

loks like you need a good small engine mechanic . stihl is a good saw , but i mainly use shindaiwa 757,s have found these bullet proof . my 031 needed points and plugs ,parts not available, got it fixed however . 066 a reliable big saw . my old ,sadly sold 090 was the best slabbing saw made ! opinion ,but heavy to cary about . but unstopable in the log. ask around,as most dealers are pretty hopeless at repairs . cheers bob

Hello weisyboy
Contrary to what malb said Stihl chainsaws do not have a "diaphragm pump to convert secondary compression pulses from the crankcase to a positive oil feed for the chain and bar". Stihl saws have a small pump that is driven by the sprocket. That way if the sprocket is not turning there is no oil being pumped to the chain. The 034 like most "Professional" range Stihl's has a split crankcase that has the oil tank incorporated into the two halves. If the gasket between these fails then you will get the problems you have described. Also the more you run the saw the more the gas will leak into the oil tank and force oil out through the external leak. Mostly a leak of this type will be caused by loose crankcase retaining screws. Has the saw been dismantled recently? A vacuum check will show any leaks. Honestly though if you are getting 200ml out of the crankcase then it is a miracle the saw starts at all.

With the 032 in addition to what malb said I would also check to see if the flywheel has not came loose and sheared the key off allowing the timing to change. Also make sure you are using the correct oil fuel mixture.

With the MS170, it would be very unusual for the fuel pickup line to have perished if the saw is only 12 months old or so however the symptoms you have described would point to a problem in that area. I suggest you have a look in the fuel tank and make sure that the filter on the end of the fuel line has not come off for some reason. Then I would check the line for leaks. It may also be a problem in the carby caused by contaminated fuel. Was the saw working fine when new or has it been a problem since you purchased it?

Regards

Phil

I agree about the Shindaiwas, Bob. I've got a 757 with a 24" bar and a 488 with 18" and they're both just fine.

4 problems fixed..

034AV: just finished putting it together after replacing the gasket witch was forked and the rubery hose thing between the carby and the saw. will run it tomorow and see how it goes.

032AV: just needed the mixture adjusting a little and sees running like a truper.

026AV: pulled it out from under teh pile of sawdust. reattached the mufler and gave the carby a clean out, new bar and chain running briliantly.

MS170: was compleatly dismantles to replace the oil hose (common problem) and reasembled so it is now oiling properly, as for the problem with the fuel after a long talk with my chainsaw man discoverd what i have long suspected. they have sealed carbys on them (no adjusters) and they need to be dismantled and clean from time to time. i have had to do this twice in the last 6 weeks a real PITA. whoever comes up with these ideas should be made to use one comertialy for a year.

so all up a god result.

Hello Carl
Glad you got the problems sorted with the saws. The 032AV may I ask how old it is?

Also in regards to the MS170, if I remember correctly it is not classed as a professional saw and therefore not subjected to the same design features as the professional range.

Regards

Phil

the 032 is about 29 years old so i have been told. it has still got the original sprocket,bar and chain on it. the chain is 50%. the bloke i baught it of was scared to use it. so in 29 years it has done no more than a couple if not less than one hour of use.

where as my 034AV owned by dad has been used an abused scince it was new 25 years ago never serviced chucked in the back of the ute and driven god knows where. for the first 15 years of its life it was used every day cutting logs for the sawmill. we got it for free so it has served us well.