036 choke and carb questions

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Gotcha, yes the contact spring seems to be bent a little. It also has some corrosion on it down at the end. They are relatively cheap so it's on my list of things to replace. It DOES look like that MAY be what's supposed to hold the master switch in the choke position, but I don't recall that spring applying that much pressure on any of my other saws. I'll have to confirm tonight. This may be the culprit to my choke issue. These two parts (spring and switch/lever) are cheap enough that I'll just have my dealer order new ones assuming they are still available. If not, it looks like I can aftermarket versions pretty cheap.
 
Pretty common, as mentioned. Squeeze one of the bends with pliers to straighten the linkage out a bit. Takes just a couple minutes and it will work fine
If the master switch was staying down, I would totally agree. Since the master switch just wants to float around, if I bend it then the choke spring on the carb is just going to push the master switch farther up and the butter fly is going to end up in the same position that it does now.

My air filter doesn't interact with anything on the carb, trigger, or master switch on any of my saws. Its just in the way to see what's going on :)
 
Hi,
Sorry, I'm out of town.

If I was home, I would look at my 026 and see exactly how it works, but I can't...

Good luck!
 
On the 036 at the spring end there are basically 3 positions or indents that the flat steel spring holds it in place or position selected. At the very top its the connection between the brass furrel on the black wire that contacts the steel spring to stop the saw, the next indent down from full up is the high idle and run , the very bottom indent is for full choke, the end of the flat spring has a cupped style bend at its bottom end, it fits into that bottom indent to hold the choke in its full closed position. If the spring itself is bent or misaligned then it likely will not hold the choke in its fully closed position.
 
While the pics JD put up are helpful I will also post a couple from my 036 project, The first pic shows the spring located into the full choke indent, the spring holds the choke into the full on position,
IMG_7878.JPG
The master switch in the same position, holding the choke in the full on condition.
IMG_7877.JPG

The pic below shows the master switch in the stop engine position, effectively grounding out the spark from the module,
IMG_7880.JPG
 
I just picked up a used 036 for what I considered a reasonable price. Unfortunately, I had to buy it sight unseen. Upon arrival, I've noticed a few issues, but I think they are fixable an it will still be a good purchase in the end.

First thing I noticed was that the butterfly on the carb doesn't close all the way when I turn the choke on unless I hold the choke/start/stop lever all the way down with my thumb. It wants to spring back up and allow the butterfly to open up over 1/4 of the way. I can't see what is supposed to keep the lever all the way down when the choke is fully engaged. This makes it a bear to start the saw when its cold. If anyone knows what keeps this down so I know where to look for issues, I'd love to hear your thoughts. I haven't tried bending the linkage any yet. No need to actually break anything right off the bat :)

Second thing I noticed was that the H/L and I markings on the side of the filter cover do not match up to their actual locations on the carb. I forgot to take a pic of this, but it looks like they are upside down. The cover has the Idle marked as being on the bottom, and the H and L jets being on top, but the carb is the other way around. I'll have to double check this and confirm it when I get home tonight, but that really struck me as weird. The cover fits the saw just fine other than that. The carb looks to be original with STIHL stamped on the bottom.

Third thing I notices was that the carb settings weren't where I would have normally expected them. L was backed out 2 full turns and H was only backed out 3/4 of a turn which seamed pretty lean. In that setting, once it warmed up, the saw wanted to scream, but had very little power. I opened it up to 1 1/4, and it runs okay there but it still seems fast (I am ordering a tach to check it for sure).

I also noticed that the little door/vent cover on the cylinder cover is missing. The one that you are supposed to open up when you're running the saw well below freezing. Seems like when the saw warms up, it's tune changes a LOT, and this might be why. Does anyone know where I can get a cover with this door in place, or a replacement door? If not, I'll fill it in so that I'm not sucking in hot air off the cylinder for no good reason.
Lastly, the ZAMA carb on this saw does not have the little square snorkel that sticks out the bottom. Can someone clue me in on what I should be looking for in terms of a replacement? If I replace the air filter (current one is worn out) along with the carb, can I go to one with the square snorkel without any other issues? The guy I purchased the saw from appears to be very mechanically inclined. I suspect that this might have been a saw that he built from pieces, or made some significant repairs to so the current carb MIGHT not actually be stock even though the bottom cover is stamped STIHL. While I believe that he's mechanically inclined, I'm CERTAIN that he didn't know anything about chainsaws just due to the conditions of the 6 safety chains and 2 bars that he included with the purchase. One bar was HEAVILY worn. The other is case hardened on one side. One of the chains is black, presumably from heat build up. NONE of the depth gauges on any of the chains have been lowered. Trying to cut was like skating on ice. Since they are Oregan safety chains, it took me 30 minutes to file the 2 depth gauges for each cutter.... Once I did that, the chains cut fine (actually great for a safety chain).

Anyway, I'd like to get the choke to work correctly, the vent door fixed, and put a new carb (and air filter) on it and then see where it goes from there. If anyone has suggestions for any of these, I'm all ears :)

Thanks,
Mark
A friend had a similar problem with the choke. Found he wasn't squeesing the throttle to full throttle before he set the choke. Once he did that it was fine.
 
Thanks everyone! I really think the contact spring is the issue with the choke. Been a busy week so I haven't made it to the dealership yet to get another one yet. If that doesn't take care of it, I'll get a new switch also. If it's still an issue after that, I'll be back. :)
Also check the indents on the master switch , they wear out over time and and once the shape and depth of the indent changes to a more flat shape the spring has less of a holding capability.
 
After reflecting on this & especially @pioneerguy600 's pics (thank you sir) I decided my saw while functional wasn't quite rite either.
Once I had tweaked the lower bend of the connecting linkage to allow the master switch to fully rotate to the choke position I found it no longer fully set the choke (possibly the same issue the OP was having). Bending the top part of the linkage (where it contacts the choke on the carb) to a more acute angle had a dramatic effect on how far the choke plate was rotated.
IMG_20220402_130740.jpg
 
After reflecting on this & especially @pioneerguy600 's pics (thank you sir) I decided my saw while functional wasn't quite rite either.
Once I had tweaked the lower bend of the connecting linkage to allow the master switch to fully rotate to the choke position I found it no longer fully set the choke (possibly the same issue the OP was having). Bending the top part of the linkage (where it contacts the choke on the carb) to a more acute angle had a dramatic effect on how far the choke plate was rotated.
View attachment 978187
Yes, I have done that also on one 034., it takes very little bending to make a big difference on the choke plate rotation, just do not over do it as the extra strain on the master switch can damage it easily, bend,distort or even break off the actuating arm that lifts the choke linkage.
 
Second thing I noticed was that the H/L and I markings on the side of the filter cover do not match up to their actual locations on the carb. I forgot to take a pic of this, but it looks like they are upside down. The cover has the Idle marked as being on the bottom, and the H and L jets being on top, but the carb is the other way around.

If your airfilter cover is the same as on my 036 Pro it sounds like someone removed and managed to shove the black insert back into the cover upside down. This is how it should be oriented:

20220402_210716.jpg
 
Yes, I have done that also on one 034., it takes very little bending to make a big difference on the choke plate rotation, just do not over do it as the extra strain on the master switch can damage it easily, bend,distort or even break off the actuating arm that lifts the choke linkage.
When working on one, I always put a little drop of oil on the choke plate shaft itself. Just to eliminate any possible friction in that area. jmho :cool: OT
 
The new spring and switch bar fixed the choke issue. The main problem was the spring, but the new switch really made it nice and solid. I did have to tweek the linkage slightly afterwards, but twisting the top end slightly so that it was perpendicular to the rest of the saw did the trick. I also ordered a cheap carb for the saw. If the rest of the problem changes with the new carb, I'll start looking for a Tilli HE-20 for it.
 
Picked up a REALLY cheap carb ($13) and installed it yesterday. Saw is running well at 1-1/4 on both jets. Just a little sluggish on the throttle, but consistent. I'll run a couple of tanks like this, before buying tilli,, but things are looking pretty good at this point.
Slow to "pick up" from idle usually means you want to go a tad richer on the L. If it's "sluggish" in general it's more likely the H is off a bit.
I'd suggest making sure the carb is properly adjusted before running a couple of tanks through it or your issues may become considerably more significant
 
Back
Top