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General Forestry => Chainsaws => Topic started by: mrcaptainbob on November 10, 2019, 09:45:40 PM

Title: Stihl can't start the Stihl MS310 !
Post by: mrcaptainbob on November 10, 2019, 09:45:40 PM
Well, some times it will, but usually won't! When it does start it runs really, really well. The issue is starter cord pulling. Okay, so I'm 'old', but NONE of the other saws have this issue. 30*'s or 80*'s does not matter. Remove the plug and the cord pulls easy. Put the plug back in and it won't matter which hand I use, the cord/crank/piston...whatever it is in there will NOT let it spin. It is the correct plug, by the way, so it's not jamming the piston. Occasionally it will spin, and, occasionally it will start.
Although I have other saws, except for the longer bar on an old Olympik, the MS310 w/20" bar is/was my go-to saw. I really miss it a lot.
There is no exhaust buildup in or around the muffler.
What else might I investigate?
Title: Re: Stihl can't start the Stihl MS310 !
Post by: Fishnuts2 on November 11, 2019, 06:13:36 PM
This might sound strange, but make sure your starter rope has not been shortened, and that you have enough rope to fill the spool on the starter out to it's edge.  Starting with a full spool gives you a lot more advantage to get the motor to spin.
Title: Re: Stihl can't start the Stihl MS310 !
Post by: mrcaptainbob on November 11, 2019, 10:03:09 PM
The rope is a good one and is the proper length. A guy could stand on that saw while another uses both hands to pull and it won't go! I'm at wit's end why it gets like this. Take the plug out...it spins freely. Put the plug in....it will ~sometimes~ get to the first compression and just simply lock up. Not flooded. Although it appears to be hydrolocked. But it's not. Will check the compression again.
I took it to the Stihl mechanic and he drop started it first pull!! Am I THAT weak??? !! Okay...., maybe so. It ran fine a few times after that, but it's now gettin' testy again and not cooperating with me. Makes no difference which hand/arm I use. It simply jams up. I've actually yanked the saw from beneath my boot while pulling that cord.
I'm at a loss.....
Title: Re: Stihl can't start the Stihl MS310 !
Post by: Pine Ridge on November 11, 2019, 11:04:16 PM
It may be easier on you to trade it in on a new saw, but it may not be easy on your wallet. 
Title: Re: Stihl can't start the Stihl MS310 !
Post by: realzed on November 12, 2019, 10:34:23 AM
Sounds electrical - like coil/timing issues..
Title: Re: Stihl can't start the Stihl MS310 !
Post by: Magicman on November 12, 2019, 01:30:15 PM
Last year I replaced my MS310 with an MS362, simply because my (old) hands could not pull the starter rope when the temps dropped.  Warm, OK, but not cold.

The new MS311 has a decompression valve which would have been OK, but I opted for the MS362.
Title: Re: Stihl can't start the Stihl MS310 !
Post by: ladylake on November 12, 2019, 01:34:08 PM
 If electrical it should pull over with the plug in and switch off.  Steve
Title: Re: Stihl can't start the Stihl MS310 !
Post by: limbwood on November 12, 2019, 02:28:08 PM
i have heard that they have a coil with built-in advance, and it sticks in the advanced mode making it harder to pull. see if it gets easier to pull with the spark plug wire unhooked from the plug.
Title: Re: Stihl can't start the Stihl MS310 !
Post by: mrcaptainbob on November 13, 2019, 09:35:52 PM
Thanks, Limbwood. I'll try that first thing tomorrow!
Title: Re: Stihl can't start the Stihl MS310 !
Post by: mrcaptainbob on November 14, 2019, 10:13:30 PM
Did not have much time this morn, but I did take the wire of the plug and gave a coule tugs. It does appear that it turned over much easier. Will verify Monday.
I think you guys may be on to sumpthin' here!
Thanks!
Title: Re: Stihl can't start the Stihl MS310 !
Post by: mrcaptainbob on November 18, 2019, 06:07:00 PM
Well, how 'bout that?!! You all made me look at the coil. I found a scratched surface on the flywheel magnets. I could see, not the coil pickup area, but the 'tail' part of the coil appeared to be dragging on the coil surface. Not much, but enough. That coil part looks like it's a foot that cleans any debris from the flywheel surface. Anyway...I put an .008" brass feeler between flywheel and that cleaner part. There already was an airgap of .008" between the coil pickup and flywheel. So....Reassembled it all and was AMAZED how it immediately started right up!! But...it now runs real raggedy. I have seen a few of the vids you all have suggested on how to adjust the carbs, but am very concerned that I might botch it and burn up an otherwise good running saw. I'll take it in to the shop and have someone who knows what they're doin' set it.
Thank you all for your help and suggestions.
Title: Re: Stihl can't start the Stihl MS310 !
Post by: Wood Shed on November 18, 2019, 06:48:18 PM
Glad to hear you are getting it figured out.  I have had a MS310 since they came out somewhere around twenty  years ago, still my go to saw.  Hope you have good stihl service, they always seem more interested in selling new saws than fixing the old ones.
Title: Re: Stihl can't start the Stihl MS310 !
Post by: mrcaptainbob on November 20, 2019, 06:19:58 PM
So I dinked around with it again today. reset the coil pickup part to.006  and that 'shoe' part of the coil to.008. AMAZING! It's like it's old self again!! Started up fine cold and hot! did some cuttin' with it and it was GREAT! Never fussed with the carb.
I am a happy camper!
but...still find it strange how this issue developed a pretty long time ago.

I'm tryin' to refrain from using a bunch more   !!! marks.
Title: Re: Stihl can't start the Stihl MS310 !
Post by: mrcaptainbob on February 03, 2020, 09:51:35 PM
It fell back to being hard to pull the rope again. But...it finally did start. Was running really, really well. All of a sudden it INSTANTLY stopped ! Could not pull the rope at all. Could not move the chain. Went to another saw and got the job done. Later on I started looking it over. Removed the bar and chain and blew it clean with compressed air. Found a puddle of black plastic in the center of the clutch cup! A difficult time to remove, but got it out and cleaned up the surfaces. Installed a new cage bearing in there and found it's FAR easier to pull start now! Could it have been going off center for such a time as to bind on the brake band??
What kind of lube should be used on that bearing when replacing? I used some hi temp, high pressure stuff. Seems to be okay so far.
And....is this something that should be lubed on occasion? Like...every ten fill ups? or twenty? Or?
  The only down side now is that it starts and runs great after it sets for a few days. Even to shut it off for a refill it stats right up again. But take a lunch break, well, might as well either let it keep running or just plan on putting it away for a few days, 'cause it AIN'T gonna start! Even with the dreaded ether. But that's a separate issue. At least the crank spins now with that new clutch cup bearing!
Title: Re: Stihl can't start the Stihl MS310 !
Post by: sawguy21 on February 03, 2020, 10:02:20 PM
The sprocket bearing only comes into play with the saw being started and idling with the chain stopped. Don't worry about it, your grease should work fine.
Title: Re: Stihl can't start the Stihl MS310 !
Post by: ladylake on February 04, 2020, 06:19:48 AM



  Sounds to me like your crank bearings are going out.  Steve
Title: Re: Stihl can't start the Stihl MS310 !
Post by: Al_Smith on February 04, 2020, 08:57:18 AM
What can happen is the starter  drum can become worn to the point it pulls over eccentric,off center .You can't really tell unless disassemble it .If that happens and it is worn that badly you'd have to have arms like "Clyde " in the movie every which way you can to pull it over .
FWIW I had the drum bushing go bad on a Husqarna 2100 CD .Now that's  a high compression 99 cc engine with a relatively small starter drum and no decomp valve .It would have been easier to rope start an 80 cubic inch Harley engine.I  made a new bushing of brass or else I never would have gotten it started .
Title: Re: Stihl can't start the Stihl MS310 !
Post by: mrcaptainbob on February 10, 2020, 09:53:28 PM
I'm convinced it was that clutch cup roller bearing. I'm thinkin' the plastic cage was getting meted for whatever reason and got off center enough for the drum to occasionaly/usually snag the brake band, getting twisted off center and binding the crankshaft. Since the bearing's been replaced it's been starting and running just fine! Like it's old self! Very happy.