ms361 L screw all the way in?

[spankrz]

oh, no... not another one... this happens with all the 361's... not even worth fixing... most dealers even make you pay a disposal fee... if you ship it to me, i guess i could take it off your hands, i could set it on the shelf...

 

[volks-man]

testing 1, 2, 3

got home early today. decided to do the press/vac test.
the saw passed.
the only things i noted just casually going over it were:
that i could turn the clamp screw a little bit on the intake boot and i got a fraction of a turn on two of the cylinder bolts. i did both of these before hooking up the gauges.

also noteworthy is that i did each test twice (actually more because my block-off-rig failed on the intake side at first) and you could hear the seal move when redoing the pressure test after the vac test. gauges still read good so i suppose i didn't blow the seals out.
so, anyone have any ideas? whats next fellas?

notice the cool homemade brake-line-brazed-to-angle-iron-muffler-replacing test plate.

 

[fourfivefour]

IMHO:
By closing the low screw you are cutting off the fuel. The saw should stall out, but it don't because your carb is dumping gas. You are covering up the rich condition by closing the low screw.
See also my previous post or refer to page 13 paragraph G."Engine Idles With Low Speed Needle Closed" of the Clymer Chainsaw Service Manual "10th edition"..........454

 

[volks-man]

Closing the mixture screw would indicate an extreme rich condition.
The carb is dumping gas, not an air leak.
The metering lever could be out of adjustment, needle not seating, or a welch plug leaking.
Have you installed a kit in the carb yet?...........454

IMHO:
By closing the low screw you are cutting off the fuel. The saw should stall out, but it don't because your carb is dumping gas. You are covering up the rich condition by closing the low screw.
See also my previous post or refer to page 13 paragraph G."Engine Idles With Low Speed Needle Closed" of the Clymer Chainsaw Service Manual "10th edition"..........454

i suspect the carb is now dumping gas.
the hard part to figure is why.
no i haven't put a kit in it yet.
i would like to figure out why something is failing on a low hour saw.
and, remember that the initial problem was high idle. now it is idleing rich and stalling unless the screw is in. so, it is running both rich and lean?!?

i'm thinking i will have to go through the carb. i do not want to but i feel i am up against it at this point.
thanks for your help.

 

[CHEVYTOWN13]

notice the cool homemade brake-line-brazed-to-angle-iron-muffler-replacing test plate.

 

[THALL10326]

got home early today. decided to do the press/vac test.
the saw passed.
the only things i noted just casually going over it were:
that i could turn the clamp screw a little bit on the intake boot and i got a fraction of a turn on two of the cylinder bolts. i did both of these before hooking up the gauges.

also noteworthy is that i did each test twice (actually more because my block-off-rig failed on the intake side at first) and you could hear the seal move when redoing the pressure test after the vac test. gauges still read good so i suppose i didn't blow the seals out.
so, anyone have any ideas? whats next fellas?

notice the cool homemade brake-line-brazed-to-angle-iron-muffler-replacing test plate.

Passed vac and pressure tests, good. Ran great when you got it back, good, I'm in the clear, my warranty on work is till it gets out the door,LOLOL

Lets get to basics. Saw has no air leaks. Coil is known good. Thats leaves a fuel delivery problem. That consists of the carb, the fuel hose, the fuel filter and tank vent. Saw runs good at full throttle, that pretty well knocks out the tank vent. Saw doesn't idle right. Check carb taps to see that they are tight. If so yank the carb, check the fuel hose for cracks, breaks or leaks. If good check the filter, if good the problem is the carb.

Since you have comfirm there are no air leaks your only 10 minutes away from checking out the rest of the saw. Hop to it..

 

[volks-man]

Lets get to basics. Saw has no air leaks. Coil is known good. Thats leaves a fuel delivery problem. That consists of the carb, the fuel hose, the fuel filter and tank vent. Saw runs good at full throttle, that pretty well knocks out the tank vent. Saw doesn't idle right. Check carb taps to see that they are tight. If so yank the carb, check the fuel hose for cracks, breaks or leaks. If good check the filter, if good the problem is the carb.

Since you have comfirm there are no air leaks your only 10 minutes away from checking out the rest of the saw. Hop to it..

look whos talkin!
where you been?
i never doubted your work.
i think i have a gremlin in the saw.
tomorrow i will go over the saw in the order you specified. if nothing appears to be amiss then i'm going to have to pull the carb down or replace it i guess.
thanks mr. hall.
i appreciate your input.

 

[THALL10326]

look whos talkin!
where you been?
i never doubted your work.
i think i have a gremlin in the saw.
tomorrow i will go over the saw in the order you specified. if nothing appears to be amiss then i'm going to have to pull the carb down or replace it i guess.
thanks mr. hall.
i appreciate your input.

Well it seems you've pretty well answered your own questions. You did the vac and pressure tests. If a saw passes those and the internals(cylinder and piston) are good there is really only two systems left to check. You know your ignition system is good from sawing with the saw. That narrows it down to the fuel system.

When you remove the carb you will notice the fuel hose take a good bend to be in place for the carb to hook into. Check that hose very closely. A slight crack in the hose can affect your idleing.

Also you say the low side screw is all the way in, you mean with the limit cap on I assume. From what your decribing the low speed side of the carb has a issue. Its allowing too much fuel to get in. That would create puddling with extended idle periods. When you pick up the saw the crankcase has to much unburnt fuel in it and causes the saw to stall slighty untill it clears out.
That fast idleing changing all the time is what we call unstable idle and its usually the fault of the carb. Check everything first though...

 

[volks-man]

Well it seems you've pretty well answered your own questions. You did the vac and pressure tests. If a saw passes those and the internals(cylinder and piston) are good there is really only two systems left to check. You know your ignition system is good from sawing with the saw. That narrows it down to the fuel system.

When you remove the carb you will notice the fuel hose take a good bend to be in place for the carb to hook into. Check that hose very closely. A slight crack in the hose can affect your idleing.

Also you say the low side screw is all the way in, you mean with the limit cap on I assume. From what your decribing the low speed side of the carb has a issue. Its allowing too much fuel to get in. That would create puddling with extended idle periods. When you pick up the saw the crankcase has to much unburnt fuel in it and causes the saw to stall slighty untill it clears out.
That fast idleing changing all the time is what we call unstable idle and its usually the fault of the carb. Check everything first though...

i usually like a roadmap before i start a project like this.

gotcha.
the limiters are still there. of note: the only mod i have done to this saw was lakes oiler mod. i haven't touched anything else.

yup, it went from fast idle, to pooling (with adjustments), to idleing pretty good with the L screw maxed 'in' (with limiter). no combination of adjustments seems right.

i will run down your checklist and take it from there.
thanks again.

 

[Bowtie]

Mail man brought me a 361 carb today from JacobJ. trimmed the limiter caps and slapped it on the saw. Problem solved, she runs like a champ!

 

[volks-man]

Mail man brought me a 361 carb today from JacobJ. trimmed the limiter caps and slapped it on the saw. Problem solved, she runs like a champ!

i threw the 361 back together today. initial runs suggests little to no change.
though i need to start over with the L H settings per service manual before i count it out for sure.

so now i am very interested in your saws problems.
what is the deal with the original carb?
is it rebuildable?
did you send the old carb to jacob to see if he could disect and diagnose it?
thanks

 

[Bowtie]

[QUOTE
so now i am very interested in your saws problems.
what is the deal with the original carb?
is it rebuildable?
did you send the old carb to jacob to see if he could disect and diagnose it?
thanks[/QUOTE]

It was running very choppy, wouldnt idle, and would suddenly die at idle. I did everything I could possibly do to make that carb work right. Cleaned it, adjusted it, then finally said to hell with it.

I didnt send the old carb to Jacob, but would have if he wanted me to, I traded him some rings for the carb I got. The old carb is junk, but I will save it for possible parts in the future.

 

[volks-man]

It was running very choppy, wouldnt idle, and would suddenly die at idle. I did everything I could possibly do to make that carb work right. Cleaned it, adjusted it, then finally said to hell with it.

I didnt send the old carb to Jacob, but would have if he wanted me to, I traded him some rings for the carb I got. The old carb is junk, but I will save it for possible parts in the future.

please explain 'running very choppy'.

when it died at idle was it like a switch was turned off, no warning?

did you have to sqeeze the throttle while pulling to restart?

ever idle too high?

any specifics you can give me are much appreciated. i know i am probably looking at replacing the carb but i like to understand how and why things fail.

thanks again!

 

[Bowtie]

please explain 'running very choppy'.

when it died at idle was it like a switch was turned off, no warning?

did you have to sqeeze the throttle while pulling to restart?

ever idle too high?

any specifics you can give me are much appreciated. i know i am probably looking at replacing the carb but i like to understand how and why things fail.

thanks again!

HAHA! You just explained it to a "T" what my saw was doing! By choppy, I mean that it would vibrate like crazy and miss at lower rpm's. Even at higher rpms it would vibrate more than it should, and just didnt run as smooth as a 361 should. I know this because I have run several new ones, and owned a good used one before this one.

Get a carb and try it!

 

[madrone]

I think it's something that involves the check valve under the welch plug. That was the problem with my carb on the 361. Process of elimination was the only diagnosis I had. It wasn't anything I could find but when I replaced it, the saw ran fine.
Bowtie, glad you got yers running again.
Volks, keep hammering at it, don't forget you like this saw,,,,right?

 

[volks-man]

I think it's something that involves the check valve under the welch plug. That was the problem with my carb on the 361. Process of elimination was the only diagnosis I had. It wasn't anything I could find but when I replaced it, the saw ran fine.
Bowtie, glad you got yers running again.
Volks, keep hammering at it, don't forget you like this saw,,,,right?

it is still fantastic to run.
light years ahead of my echos and even the 026.
shoot i can use it all day if i am mindfull of the pooling. even then it really isn't any worse than using most saws.

i covered the welch plugs in rtv to be sure they weren't leaking.
that would have been too easy a fix i guess.

 

[CentaurG2]

please explain 'running very choppy'.

when it died at idle was it like a switch was turned off, no warning?

did you have to sqeeze the throttle while pulling to restart?

ever idle too high?

any specifics you can give me are much appreciated. i know i am probably looking at replacing the carb but i like to understand how and why things fail.

thanks again!

Please explain:

Running choppy.. and we wonder why he is called brian/brain.

Ever died at idle… nope the ms361 purrs like a kitten with a heart murmur.

Squeeze the throttle while pulling the restart… yea that’s on page 14 of the owners manual brian/brain.

Any specifics you can give me are much appreciated… Gods what an open book..bottom line, you bought into the uber hype,your saws out o warrantee, nows yous gots to pay. What else do you need to know?

 

[Bowtie]

Please explain:

Running choppy.. and we wonder why he is called brian/brain.

Ever died at idle… nope the ms361 purrs like a kitten with a heart murmur.

Squeeze the throttle while pulling the restart… yea that’s on page 14 of the owners manual brian/brain.

Any specifics you can give me are much appreciated… Gods what an open book..bottom line, you bought into the uber hype,your saws out o warrantee, nows yous gots to pay. What else do you need to know?

Very uneducated/stupid post.

 

[Andyshine77]

Have you tried mixing up some fresh fuel from a different gas station. Last summer I had the same problem with two of my saws, it turned out to be bad gas from a local Sunoco station. Hay it's worth a try.

 

[Lakeside53]

i covered the welch plugs in rtv to be sure they weren't leaking.
that would have been too easy a fix i guess.

Never ever use RTV in gas.. it will swell and peal up.