Author Topic: Stihl chainsaw troubles. (Read 7252 times)

Spanky · « **on:** July 14, 2009, 05:19:55 PM »

My uncle gave me his old Stihl 045 chainsaw and it's giving me fits. Sometimes it will start right up first or second pull and run great, sometimes it will start and run for a minute or two and sometimes it won't start at all. I have put a new plug and air filter in it and it made no difference. It runs very strong when it runs. If I could get it to run all the time I would be a happy camper. Anyone with advice please chime in and help me out. This is the first Stihl I've ever owned and have never worked on one.
SOMEONE HELP ME OUT WITH THIS THING!!

Spanky

flintlock · « **Reply #1 on:** July 15, 2009, 04:35:54 AM »

My first guess is that you either have water or trash in the gas, if it's been sitting awhile without running the gas could have gone bad...

I'd start by pouring the gas out of the tank and mixing a new batch, filling her up and seeing if this helps...

If not, you will probably need to have the carb cleaned and rebuilt...This is very common for any engine that sits up for awhile...I'd also condition with gas stabilizer if you plan to store more than 3-4 months...

ShadowMover · « **Reply #2 on:** July 15, 2009, 11:11:03 AM »

It's tough to generalize about what's wrong, but a mechanic friend once told me 90% or carburetor problems are ignition problems. You could pull the plug, and ground the outside of the plug to the cylinder and crank it over. Do this in the shade so you can see the spark. If you have no spark, it will not run. Many of the newer type small engines have a solid state ignition system that can crap out when they get hot or just whenever they want. Check the spark right after it quits.

A problem I had with a chainsaw that would run fine sometimes, but not cut or pull a load, was the fuel line inside the tank to the carb had cracked and would suck air or gas depending on how it was held. It drove me nuts until I found the little crack. BTW they sell chainsaw sized gas line in hobby shops that carry model airplane engines. They carry stuff for nitro fueled engines and some for gasoline. Get the gasoline type. I wasted a whole day driving around looking for fuel line for that old chainsaw before I found the hobby shop.

JBlk · « **Reply #3 on:** July 16, 2009, 04:02:06 AM »

I would agree that most problems are ignition problems.Worked in a garage as a young man and the boss always said to listen to the customer complain about his fuel problems and smile alot and then fix the ignition as soon as he leaves.When I owned a small engine shop I found that wisdom still prevailed.Take your saw case apart and using compressed air blow out the saw dust around the switch and flywheel area.Check the gap between the flywheel magnets and the pickup legs on your coil or solid state device, should be around .010.Check to make sure you have fire at the plug and then try to start it again.If it still doesn't run, take off the air cleaner and give it a shot of carbureator cleaner in the carb.If it fires up and runs until the carb cleaner is used up you have a fuel problem.Take off the side of the carb that the gas goes into and carefully remove the small screen about the size of a pencil eraser from the hole and soak in acetone.Don't use compressed air on the screen or you will lose it forever.

Spanky · « **Reply #4 on:** July 17, 2009, 11:56:01 AM »

Thanks for the tips guys. It has spark but it's weak $:-\$
I'll pull it apart and clean everything up and check the gap.
Hopefully that'll straighten it out.

Spanky

mirage1988 · « **Reply #5 on:** July 17, 2009, 03:50:29 PM »

Sounds more like a fuel or carb problem since it's intermittent. Once an ignition part fails the motor will not run. The spark may look weak with an old or partly fouled plug. Get a new plug and some fresh gas I bet it will run like a top.

Cornbelt · « **Reply #6 on:** July 19, 2009, 09:09:53 AM »

After you get it running good, it will be a lot more dependable if you pour out the gas when you're done and run the engine till it quits, especially if you may not be using it for a while. Had one for 20 yrs, and it never failed to start when I did this. Wish I could say the same for my McCullough.

hillbill · « **Reply #7 on:** July 25, 2009, 12:43:36 PM »

not sure how old your saw is but the cracked fuel line thing is a big prob on the ones made in the last 15 yrs or so.its a easy fix if your familar with that type of saw.a saw that has been sitting for awhile often has varnish or crud in the carb.not a big deal, sometime just a removal and cleaning and reassembly takes care of it.way i look at it yu can take it apart about 5 times and learn alot and still be ahead of takeing it to your local 45$ per hr tech.one thing about those bigger saws is that they freekin vibrate apart like a old harley. when goin back together with it i like to use sum blue loctite here and there to keep it from happening again.

30-30man · « **Reply #8 on:** July 26, 2009, 01:03:19 PM »

Almost all the Sthl stuff I've seen has been like you stated. I don't know why. I've had $100 Poulans that cranked on the 2nd pull for over 15 years or more. I think I would first start looking for air leak around the carb. Then check the lines and last replace the diaphram in the carb. The last thing you could do is trade it in on a Husky. I decided on a Husky with a chainsaw when I noticed about all the Stihls I've seen have been hard to crank and all the Poulans had that toolless adjustment crap.

Travis Morgan · « **Reply #9 on:** July 29, 2009, 11:41:35 AM »

Try changing your fuel filter and fuel line.

torpedoman · « **Reply #10 on:** July 29, 2009, 12:39:15 PM »

Quote from: Travis Morgan on July 29, 2009, 11:41:35 AM

Try changing your fuel filter and fuel line.

+1

WD45 · « **Reply #11 on:** August 22, 2009, 05:24:31 AM »

Most chain saw probs I have seen are carb related. The most neglected thing on a chain saw is usually the air filter. They are not like your lawn mower and should be cleaned or replaced often. I clean mine every couple truck loads cut. It doesn't take much saw dust in the carb to cause all kinds of problems. They stopped using that number system several years ago so you have an older saw and may just need a good carb cleaning and rebuild. The other thing that can cause probs is the exaust port and or the muffler clogged with carbon.

Travis Morgan · « **Reply #12 on:** August 24, 2009, 10:14:29 AM »

I tried just dusting off or blowing out air filters since Stihl ones are so damned expensive, and ended up burning up the top end in my saw. Cost me about $130 for a rebuild the dealer wouldn't guarantee. I took it to an auction.

LEO · « **Reply #13 on:** February 08, 2010, 01:26:53 AM »

I know this is belated but if you haven't fixed the problem try changing the fuel tank cap. I had a similar porblem and this fixed it apparently there is a vent in there and if it messes up the fuel can flow out of the tank properly.

Rex in OTZ · « **Reply #14 on:** February 08, 2010, 10:34:58 AM »

Troubleshooting is a good start.
#1 do you have gas
#2 do you have spark
#3 do you have comperession
#4 check for obstructed air or exhaust
Like snowmobiles and outboards they all are hard on sparkplugs, just simpliy sparking the plug isant really a indicator of a good sparkplug, the best way to spark check a plug is in a sparkplug checker useing a coil and supplied air pressure, the dim spark may be just a bum plug, get a new one and try it out.

On average I go through allot of 2 cycle sparkplugs in a winter on my snowmobile 7-12 sets here in NW Alaska, if you have access to a sparkplug servicer/checker great, just assumeing the plug sparkles a little bit doesent mean it will work under compression.

Clean gas and a new sparkplug, pay attention the the gasoline you use I live in a area where they dont have methinol blended gasoline, your area might and this could lead to all sorts of seal problems (attack the rubber seals) and a deteriorate the suction fuel line.

SHOOTALL · « **Reply #15 on:** February 08, 2010, 10:39:18 AM »

Run some seafoam thru it mixed in . Also use a 2 cycle mix that works with the new gas , same for boats etc.

mbopp · « **Reply #16 on:** February 09, 2010, 01:17:17 AM »

Try

www.arboristsite.com

and go to the Chainsaw forum. If those guys can't help you nobody can.

efremtags · « **Reply #17 on:** February 16, 2010, 12:53:54 PM »

The 045 is an older model. It may have worn pistons. I had an issue with a 046 magnum, it would run great for a few minutes then not run for dam. This is only after you investigate the obvious like fuel line and spark plug. You can pull off the muffler and look into the bore. If it isn't shiny, that's the issue.

BIG Dog454 · « **Reply #18 on:** March 24, 2010, 11:50:08 AM »

I fix a lot of chain saws (my shop), the biggest problem is people don't mix the fuel correctly, they just guess. Mix the fuel according to specs, if it's 4 OZ. to a gal then get a measuring cup and get 4 OZ of oil and measure out 1 gal of gas. Synthetic oil has fixed a lot of saws for me, Ames (or is it aims) or laser synthetic oil is great for chain saws. In my opinion Champion Spark plugs are junk, if your using one try a different brand. as has been mentioned clean your saw regularly. Full chisel chains are great for the profesional, but semi chisel chains are easier to sharpen correctly and withstand dirt and are more forgiving. just from my experiences my $.02.

Horsefeathers · « **Reply #19 on:** April 20, 2010, 10:03:52 AM »

I got a new Stihl saw ,I think it was a Farm Boss .It was defective out of the box.It wouldnt start. the dealer played with it and gave up .He gave me a new one That one was also defective. I got one of those Easy Starts instead .That was a couple of years ago. Its a good saw ,no problems and it cuts good.Lemons can show up with any product from time to time. Horsefeathers.

Rex in OTZ · « **Reply #20 on:** May 11, 2010, 12:48:06 PM »

The fast and easy way most folks use to see if a sparkplug is any good is spark it off the side the head, in most cases it works but ther's a trap laying there one must be aware of.
From what Ive experenced useing a aircraft spark plug checker useing a step down bushing to fit the smaller shank spark plug, (by simply grounding the plug on the cylinder head and pulling it through, it may show a blue flash, but dont assume its a good sparkplug), on sparkplug servicers they use a coil to spark the plug while the sparkplug is screwd into a air pressurized cylinder (thats the clincher) if it sparks in the pressurized space viewd through the witness port.
Ive had a few bad experences of sparkplugs plugs that sparked a blue or green a little just sitting on top the cylinder.
Working with aircraft sparkplugh they quite oftin run in excess of $26ea with 4cyl engines useing 8 plugs.
The most troublesome problem involved a aircraft combustion air heater, the plug was too big to sit in the pressure well so i tested it with a substituted lead, turns out that lead in combination with the open unpressurized sparking of the plug it worked just fine on the bench and on the ground in the aircraft with the ground blower running, once in the air the supplied ram air(morecfm than the ground blower) the weak sparkplug wouldent sustain combustion and the heater wouldent work in flight and had cold flyers complaining, a new igniter plug fixed the problem.

FourBee · « **Reply #21 on:** January 10, 2011, 05:32:22 AM »

Quote

Spanky ~ My uncle gave me his old Stihl 045 chainsaw and it's giving me fits

Hey Spanky: Did you ever solve the problem ? Like several others have stated, I'd check out the fuel lines for the least sign of deterioration. Cracks around the connecting ports. Don't overlook the fuel filter inside the gas tank. Replace it with a new one even if it looks okay. Those 2 replacements will make a saw run like new.

bigbird09 · « **Reply #22 on:** January 12, 2011, 03:25:38 PM »

this is kinda old, and I did not read everything in it, mainly glanced over it. 90% of the sthil saws I ever seen in the shop where in there with carb related problems, usually required a rebuild. Also its a good Idea to replace the fuel line to the carb, and any vent lines coming off the carb, and don't forget about the filter in the tank. Also its a good Idea for a new filter and pulling the plastic off and blowing all the caked in saw dust out. Last thing, stihls can be finiky to start. Not sure how old or new yours is, if its an 045 than its at least a few years old. Any stihl that has the choke/run switch to the left of the throttle, the standard starting procedure is to move the selector to full choke and pull it till it first attempts to fire, once it does move it down one click to the half choke position and continue till it starts, then when you pull the trigger it should automatically kick down to the run position. I don't know how many time people have picked up a saw from service went out to the vehicle tried to start it and couldn't get it to start, brought it back in, and said it didn't run. After going through this procedure they would fire every time.