Carb screw governors at richest setting.

[Matthew Steingass]

We work at 7 to 10,000 feet and I have a few tools that seem to need more fuel off idle (bogs) and I can't get to 4 stroke wide open. These are older tools with an unknown history at a not for profit. I've never been through the the life of a saw so I'm wondering what we should do. Fuel and impulse lines? Crank seals? Carb? We put new a spark plug and filters this year on the wood boss which is when I needed to add fuel. No irratic idle. Cleaned spark arrestor. The other saw is a farm boss and a hedge trimmer which is a different breed for me.

 

[rupedoggy]

Would you be so kind as to tell us the model of saw and what exactly you mean by governors? Do you mean the adjustment screws? Have you rebuilt the carburetors? Help we want to give, minds we can not read. Does your 372, 034 and 020t run correctly?

 

[Matthew Steingass]

Would you be so kind as to tell us the model of saw and what exactly you mean by governors? Do you mean the adjustment screws? Have you rebuilt the carburetors? Help we want to give, minds we can not read. Does your 372, 034 and 020t run correctly?

Ms 251 and a 271. My saws run well. Yes I mean the limits on the carb screws. Carbs haven't been rebuilt.

 

[rupedoggy]

Interesting that your own saws are what I would call Pro saws and the ones you are trying to use are Homeowner type saws. Ditch those "governors" and adjust. Can't you see the problem here?

 

[Matthew Steingass]

Ms 251 and a 271. My saws run well. Yes I mean the limits on the carb screws. Carbs haven't been rebuilt.

Interesting that your own saws are what I would call Pro saws and the ones you are trying to use are Homeowner type saws. Ditch those "governors" and adjust. Can't you see the problem here?

 

[Matthew Steingass]

Thats why I'm torn on putting much free time into them or asking them to get me parts. I don't like their saws lol. When I rebuild a saw I rip through money and there's a lot of trial and error. I've been wanting to just pull the governors and run them till they won't.

 

[heimannm]

Those are "limiters" not governors, using the correct terminology would help others help you.

Normally at higher elevations the air is less dense and so the adjustments need to be adjusted leaner (more lean??) to run properly. If you have to take them to the limit on increasing fuel and they still don't work properly you probably need to look at fuel filters, tank vents, or the diaphragms & screens in the carburetor.

Mark

 

[Matthew Steingass]

Interesting that your own saws are what I would call Pro saws and the ones you are trying to use are Homeowner type saws. Ditch those "governors" and adjust. Can't you see the problem here?

Im

Those are "limiters" not governors, using the correct terminology would help others help you.

Normally at higher elevations the air is less dense and so the adjustments need to be adjusted leaner (more lean??) to run properly. If you have to take them to the limit on increasing fuel and they still don't work properly you probably need to look at fuel filters, tank vents, or the diaphragms & screens in the carburetor.

Mark

Thanks for the info and advise. I'll go for some diagrams first. It doesn't run erratically and only stumbles off idle here and there. I figured it was getting outside air given our elevation and how rich I have it. About half it's life was ethanol gas other half ethanol free.

 

[user 122190]

Find what works and stay with it until there is a serious problem. We have here some that claim to make carb adjustments daily/hourly and even in the cut. Who can tell what is an exaggeration or just complete BS. I haven't adjusted my ms461 for over 2 years. When I did, I soon put it back, learning that fiddling with these adjustments is an opening of a Pandora box. Leave working well alone.

 

[Matthew Steingass]

Find what works and stay with it until there is a serious problem. We have here some that claim to make carb adjustments daily/hourly and even in the cut. Who can tell what is an exaggeration or just complete BS. I haven't adjusted my ms461 for over 2 years. When I did, I soon put it back, learning that fiddling with these adjustments is an opening of a Pandora box. Leave working well alone.

My 020t has has parts from two different carbs so I can have a walbro carb with a high speed adjustment. I've started from zero a few times before but I can't quite get there with these saws.

 

[4CornersPuddle]

Matthew, I agree that removing the limiters on the carb screws may be the first approach to take. And, check those filters.
My timber felling career began near where you are. I logged for Smiths, Blazzard, and Leavitts and lived in Kamas, starting in 1972. We were all over the high country and up to 10,000 feet in the Uintas. I made lots of sawlogs on the Upper Setting road and got to cut some dandy Englemann spruce up to 5' in diameter in the Current Creek drainage.
We certainly found we had to adjust the carbs on those old Homelites and our Huskys if we changed elevation more that 600' to 800'. Good luck on getting those Stihls dialed in. Unless they have air leaks, you'll probably get them pulling well in short order.

 

[Matthew Steingass]

Matthew, I agree that removing the limiters on the carb screws may be the first approach to take. And, check those filters.
My timber felling career began near where you are. I logged for Smiths, Blazzard, and Leavitts and lived in Kamas, starting in 1972. We were all over the high country and up to 10,000 feet in the Uintas. I made lots of sawlogs on the Upper Setting road and got to cut some dandy Englemann spruce up to 5' in diameter in the Current Creek drainage.
We certainly found we had to adjust the carbs on those old Homelites and our Huskys if we changed elevation more that 600' to 800'. Good luck on getting those Stihls dialed in. Unless they have air leaks, you'll probably get them pulling well in short order.

I appreciate you're input. Beautiful country out here. I'll clean the carb and pull the limiters tomorrow morning and see how she does.

 

[SteveSr]

I've been wanting to just pull the governors and run them till they won't.

This is why limiter caps were invented... to allow compensating for changes in temperature and mostly elevation. If the caps are properly adjusted they should be full CCW (rich) at sea level. At high elevation they should be close to full CW (lean) to compensate for significantly reduced air density at high elevation. It sounds like your saws are not running right because they are too rich. I would try leaning them out and see how that works. There is no good reason to pull the limiter caps if the saw can be properly adjusted with them on. It also prevents other users from ruining a saw by mis-adjusting them. Limiter caps also have a base "stock" setting which is NOT what is printed on the side of the AF housing which would normally be waaaay too lean. So if you pull the caps you are ripe for mis-adjustment and a burned up saw.

 

[rupedoggy]

This is why limiter caps were invented... to allow compensating for changes in temperature and mostly elevation.

That is NOT why limiter cap were invented! Do you work for the EPA? Get a clue. Your diatribe sounds great, it just isn't so. Sorry

 

[OM617YOTA]

Never had a two stroke engine I could tune properly with the limiter caps in place. Whatever the reasoning was behind limiter caps, proper operation for best power and longevity of the engine sure isn't how the implementation turned out.

Ignoring all the functionality issues, does a properly tuned saw, vs. an EPA tuned saw, really emit more pollution than the manufacturing required to replace a burned up saw a bunch of times? Of course not.

 

[HarleyT]

Here is the manual.

 

[SteveSr]

That is NOT why limiter cap were invented! Do you work for the EPA? Get a clue. Your diatribe sounds great, it just isn't so. Sorry

Well, I would beg to differ. While EPA was definitely a part of the reason to limit adjustment for emissions reason. The reason that limiter caps exist is because fixed jet carbs didin't work very well over temperature and elevation changes. That is WHY limiter caps were added as the fixed jet carbs went away. So , yes, I do have a clue. Do you?

 

[HarleyT]

EPA thread!!!!!

 

[super3]

Well, I would beg to differ. While EPA was definitely a part of the reason to limit adjustment for emissions reason. The reason that limiter caps exist is because fixed jet carbs didin't work very well over temperature and elevation changes. That is WHY limiter caps were added as the fixed jet carbs went away. So , yes, I do have a clue. Do you?

Wrong

 

[toadman]

My 291 I rebuilt after it was killed & (possibly) straight gassed the first day (same chassis as the 271) was super RICH from the factory on the low speed setting and sluggish/boggy to an annoying amount on pulling the trigger. I had to remove the caps & richen the high side & lean the low, both spots I set it where outside the caps limits, but opposite of each other in reason for removing the caps.
The 4 stroke sound was very hard to hear on mine, not sure why, (maybe somebody else will chime in) but it took a few hours on and off of frustrating fiddling and cutting for me to realize it was there & I just couldn't distinguish it very well like I can on most of my other saws. It showed up very clearly on video though, which is what I eventually used to tune it & then I could hear it IRL.
Edit: I got this 291 out of the shop's dumpster only one day old after I watched a "pro" kill it on a neighbors tree next to my house by making multiple 20 minute each noodle cuts on a rocked chain as it's first cuts out of the box. It may not be a typical example, I don't know. it does have all OEM parts, so should be & I didn't touch the carb until I had it back together again.