Carburetor Help Needed

[apn73]

Hello All,
I tried to start up my Stihl MS-361 for the first time in over year today, and couldn't keep it running. It started with no issues, would even run on the mid-choke high idle for pretty long periods time, but it wouldn't idle long before it stalled. Sometimes it would idle and I would have good throttle response for a bit, and then stall. One time while I had it running on high idle, and it was running perfectly, it just stalled out again. There isn't really a pattern to it, it's just doing whenever, and it won't run long enough to do any cutting.

The saw is 9 years old, was produced in mid-2007, and I wasn't as vigilant as I should have been with keeping the ethanol out of the carb. I wouldn't be surprised if that neglect finally caught up to me. I believe, and correct me if I'm wrong, it uses a Walbro HD 34A. Is there a site sponsor out there that sells the OEM rebuild kits for these? Is there another reason that the saw is running this way?
Thanks in advance,
Adam.

 

[7sleeper]

Did you use fresh mix?

7

 

[apn73]

Did you use fresh mix?

7

Yes, that's one of the first things that I did. It made some improvement, but didn't get it all to the way to running right.

 

[AVB]

If it is the HD then K10-HD is Walbro repair kit.

 

[apn73]

If it is the HD then K10-HD is Walbro repair kit.

Thanks for that, did the MS361 ever use anything other than the Walbro HD?

 

[sawfixer]

I just went through the same problem with my MS361 with a Walbro HD34A carb. I put in a K10-HD kit and it didn't help. It would run good for a little bit and then not start and I'd have to tune it all over again. I thought I had an air leak as the saw would run away and then quit but a pressure and vacuum check showed everything was okay. I ended up going with an Ebay direct from China carb for $14 with free shipping. This replacement carb fixed all of my issues for the last couple of months since it has been installed. I think the problem with the HD34A was the fuel pump circuit which wore out the bore. I deleted it based upon guidance on this website and it helped a little but the carb still would never stay stable in the settings. I would go with the K10-HD kit and then if no improvement, go to the Ebay route for the lowest cost option.

 

[apn73]

I just went through the same problem with my MS361 with a Walbro HD34A carb. I put in a K10-HD kit and it didn't help. It would run good for a little bit and then not start and I'd have to tune it all over again. I thought I had an air leak as the saw would run away and then quit but a pressure and vacuum check showed everything was okay. I ended up going with an Ebay direct from China carb for $14 with free shipping. This replacement carb fixed all of my issues for the last couple of months since it has been installed. I think the problem with the HD34A was the fuel pump circuit which wore out the bore. I deleted it based upon guidance on this website and it helped a little but the carb still would never stay stable in the settings. I would go with the K10-HD kit and then if no improvement, go to the Ebay route for the lowest cost option.

Disappointing to read that the HD34A has it's flaws and I hope I don't have to go that route, but it sounds like we're having the same issue. Thank you for the information, I'll try the kit.

 

[apn73]

Stupid question, does the flippy cap function as the tank vent?

 

[blsnelling]

Stupid question, does the flippy cap function as the tank vent?

No.

 

[apn73]

No.

Thanks for weighing in Brad, have you been seeing issues with HD34A's? Any thoughts on this?

 

[blsnelling]

I'm not aware of any issues. I would simply rebuild the carb, inspect the fuel and impulse lines, replace the spark plug and be done with it. The 361 is a fantastic saw.

 

[birdcolonel]

could your fuel filter be gummed/clogged?
reason i ask is just cause you mention it's been sitting for a while
during that time the volatile part of whatever fuel mix was left in it has evaporated and only the goo remains
could be gum/goo in the filter/lines/carb itself
if it ran fine last year when you shut it down, then probably nothing mechanical wrong with the carb - just stopped up
jmho

 

[HarleyT]

It is important to remove the needle/lever/spring, and ensure that the passage underneath is totally clear, it gets partially clogged with gunk and varnish, and most folks skip this step, to avoid dealing with the tiny spring/parts.

 

[HarleyT]

The #0000 007 1071 kit is @10.49 at the Stihl dealers here in Ky.

 

[apn73]

could your fuel filter be gummed/clogged?
reason i ask is just cause you mention it's been sitting for a while
during that time the volatile part of whatever fuel mix was left in it has evaporated and only the goo remains
could be gum/goo in the filter/lines/carb itself
if it ran fine last year when you shut it down, then probably nothing mechanical wrong with the carb - just stopped up
jmho

I was going to try that next because it's easy and quick, but I'm not holding my breath that that is the magic fix. Could be though.

 

[apn73]

It is important to remove the needle/lever/spring, and ensure that the passage underneath is totally clear, it gets partially clogged with gunk and varnish, and most folks skip this step, to avoid dealing with the tiny spring/parts.

Thanks HarleyT, good stuff.