MS 361 dies out after creeping on the throttle a bit… need some help with tuning

[2-StrokeDude]

Pressure and vac test is literally a 5 minute job, shouldn’t be difficult?

Edit: you said “aftermarket carb” you should have said that originally.. all bets are off for that thing working as it should… bin it and rebuild your oem one

I Would be rebuilding that OEM carb if I could, but it’s not going to be worth it since this happened to it…. H screw is busted off. That’s how it came when I got a saw.

I know OEM is 1 million times better and I would totally be using it if I could. I’ve got an ultrasonic cleaner that I use just to try to save the OEM stuff. For someone who doesn’t use chainsaws that much I can’t justify buying an OEM carb. It’s just too expensive when I’m on a budget.

 

[lone wolf]

Yes, I have tried opening the L jet, doesn’t seem like it’s helped a whole lot. I’ll try and start the saw today and mess with the carb tuning a little bit more, hopefully I can get it figured out. Just really hoping it’s not any air leaks since I don’t wanna have to pressure/vac test again, that was a pain.

According to the manual, the initial settings without the limiter caps on is one turn for both the L and H screw. Maybe I’ll just set it to that and try and adjust from there.

The aftermarket carb did not have those limiter caps on there so hopefully adjustments aren’t coming loose or anything.

Aftermarket carbs can vary on the settings compared to OEM, that's another problem.

 

[lone wolf]

I Would be rebuilding that OEM carb if I could, but it’s not going to be worth it since this happened to it…. H screw is busted off. That’s how it came when I got a saw.

I know OEM is 1 million times better and I would totally be using it if I could. I’ve got an ultrasonic cleaner that I use just to try to save the OEM stuff. For someone who doesn’t use chainsaws that much I can’t justify buying an OEM carb. It’s just too expensive when I’m on a budget.

Then borrow an OEM carb from a friend if you can locate one to test this all out.

 

[lone wolf]

I just watched your video and that could be an air leak.

 

[pioneerguy600]

Rubber occluders is the way to go for vac and pressure testing, it takes a bit of finess to install them and get them right the first time every time, sort of a learned art but they sure speed up tests.

 

[pioneerguy600]

The two tools I use to adjust the cheap AM carbs with,

 

[ZeroJunk]

The two tools I use to adjust the cheap AM carbs with,

Yeah, and I have dozens of them out there running fine at a savings maybe in the thousands of dollars.

Lot of monkey see monkey do. IOW, most of these guys bashing aftermarket carbs have either never used one, or tried that the problem never had anything to do with the carb to start with. Or, got a bad one.

Guess what . I replace bad OEM carbs with some regularity.

Just how much do you think there is to a carb ?

If the butterfly sticks, that is a QC problem. If pulling the throttle lever does not release it off choke that is a QC problem.

I promise I have replaced at least 50 carbs with aftermarket and run them on my own saws.
Four or five were bad. So What.

Send your MS361 to me and I will have it running. That is a fact.

 

[2-StrokeDude]

Yeah, and I have dozens of them out there running fine at a savings maybe in the thousands of dollars.

Lot of monkey see monkey do. IOW, most of these guys bashing aftermarket carbs have either never used one, or tried that the problem never had anything to do with the carb to start with. Or, got a bad one.

Guess what . I replace bad OEM carbs with some regularity.

Just how much do you think there is to a carb ?

If the butterfly sticks, that is a QC problem. If pulling the throttle lever does not release it off choke that is a QC problem.

I promise I have replaced at least 50 carbs with aftermarket and run them on my own saws.
Four or five were bad. So What.

Send your MS361 to me and I will have it running. That is a fact.

Yup I don’t get people bashing all the aftermarket carbs, like you said, there’s not much to them once you understand how they work.

I’ll try some more tuning stuff and hopefully that works, really hoping it’s not an air leak. If it’s an air leak I just don’t understand that since it pasted the vacuum and pressure test.

And, if it’s an air leak then how is the thing able to idle for minutes on end on upside down on its side or any position? Just hoping I’ll be able to figure it out and it doesn’t burn up the saw, seems like it Has to be a minor air leak if anything. I’ll try replacing the impulse hose line as well since that is hardened up.

 

[ZeroJunk]

Yeah, the Chinese took the OEM carbs and copied them. Copied them. Or, they make them on the same line as they make the OEM ones on. Just take the stampings off.

Funny, they can make an I phone , but not a carb.

I would pay twice for an OEM Stihl probably, like $40 . But, I can assure they have no more in their OEM carb than the generic copies.

 

[lone wolf]

Yeah, the Chinese took the OEM carbs and copied them. Copied them. Or, they make them on the same line as they make the OEM ones on. Just take the stampings off.

Funny, they can make an I phone , but not a carb.

I would pay twice for an OEM Stihl probably, like $40 . But, I can assure they have no more in their OEM carb than the generic copies.

My climber can tell a stock MS 200T carb from a knock off just by the throttle pull, it took him about 2 seconds to complain. I snuck one in without telling him just to see if he could tell any difference and not to mention it didnt idle and run as well either. So OEM carbs on saws is always better.

 

[ZeroJunk]

My climber can tell a stock MS 200T carb from a knock off just by the throttle pull, it took him about 2 seconds to complain. I snuck one in without telling him just to see if he could tell any difference and not to mention it didnt idle and run as well either. So OEM carbs on saws is always better.

Not sure about a hot rod MS200T ..

My MS660 has an aftermarket carb. My BR600 and BR700 have aftermarket carb. My FS91 has aftermarket carb.

They run fine. I can buy OEM at cost plus 10, you might be surprised how cheap that is.

Really don't see the point of getting bent over. Think ya'll imagine most of this.

 

[pioneerguy600]

Yeah, and I have dozens of them out there running fine at a savings maybe in the thousands of dollars.

Lot of monkey see monkey do. IOW, most of these guys bashing aftermarket carbs have either never used one, or tried that the problem never had anything to do with the carb to start with. Or, got a bad one.

Guess what . I replace bad OEM carbs with some regularity.

Just how much do you think there is to a carb ?

If the butterfly sticks, that is a QC problem. If pulling the throttle lever does not release it off choke that is a QC problem.

I promise I have replaced at least 50 carbs with aftermarket and run them on my own saws.
Four or five were bad. So What.

Send your MS361 to me and I will have it running. That is a fact.

If the 5 lb adjuster does not work then I reach for ole blue, the 10 lb. adjuster it always adjusts them just right.

 

[ZeroJunk]

BTW. That 200T with the accelerator pump is a little different breed of cat. I have replaced that pump in some. Not sure if it is even available as a part now. And, I'm not sure if aftermarket carbs even have it. I know some on here disabled the thing and sealed it off from the start.


I still have to say that generic carbs work fine for me most of the time.

I'm thinking at least some of you are just parroting and have never even tried one.

 

[ZeroJunk]

If the 5 lb adjuster does not work then I reach for ole blue, the 10 lb. adjuster it always adjusts them just right.

Yeah, I can see where you might be better off sticking with OEM .

 

[pioneerguy600]

Yeah, I can see where you might be better off sticking with OEM .

Whatever works for you the individual, what works for me works for me, I don`t try to persuade others.

 

[lone wolf]

Not sure about a hot rod MS200T ..

My MS660 has an aftermarket carb. My BR600 and BR700 have aftermarket carb. My FS91 has aftermarket carb.

They run fine. I can buy OEM at cost plus 10, you might be surprised how cheap that is.

Really don't see the point of getting bent over. Think ya'll imagine most of this.

BTW. That 200T with the accelerator pump is a little different breed of cat. I have replaced that pump in some. Not sure if it is even available as a part now. And, I'm not sure if aftermarket carbs even have it. I know some on here disabled the thing and sealed it off from the start.


I still have to say that generic carbs work fine for me most of the time.

I'm thinking at least some of you are just parroting and have never even tried one.

Sealing it works half the time. If you take the H needle out and spray carb cleaner in the hole, and it leaks out the little metal plate that would be the air leak.

 

[Vintage Engine Repairs]

I put an aftermarket carb on an 028 Super for a friend last week. It had been in the shop for a while since I usually buy three at a time.

Idled fine. But, it was too lean on high side. So, I turned a 1/4 turn richer. Nothing. Another 1/4 turn . Nothing. 1/2 turn, still 14, 000 or better. I was about to throw it in the trash, and opened it up like another full turn. Pig rich.

So, the high needle actually did it's function about 3 turns, maybe more, out and worked fine.

It's a little rich to bash Chinese made carbs when they are all made there.

QC not as good I'm sure but, I seem to have good luck with them.

Buy about 5 at a time for BR500,550,600,700. Five at a time for FS90's FS85's FS91's .

Doesn't mean you didn't get a bad. Doesn't mean rebuilding the old one is a bad idea .

It’s not about bashing a Chinese product, it’s about being cautious that it’s after market. China make great products - some of their after market parts arr fantastic (carb kits especially) but it’s important to reiterate that carbs made aftermarket without the Q/C of a company like walbro of Zama (Stihl) looking over them will often cause issues. I know you know this, it’s more for anyone who reads in the future.

 

[Old2stroke]

For what it's worth, I buy only AM carbs and kits so here are a few observations. As far as I can tell the items in the repair kits are identical to the OEM in terms of material and precision of manufacture, you just have to be sure that the kit has a pump diaphragm that EXACTLY matches your original. I have heard of people getting a main diaphragm that has a larger nub that operates the control lever causing flooding issues but I have not seen this.
Consistent quality control is an issue with the carbs so there is a risk that you might get a faulty one. I have only ever had 1 that was defective. When you buy one of these, before installation you should take it apart and verify the setting of the control lever and ensure that the pump has the right diaphragm. Drill a small hole in the centre of the cover of the main diaphragm and pressure test the inlet valve to confirm it will hold pressure, then use a toothpick in the cover hole to depress the diaphragm slightly to confirm it will open the valve. The thread pitch and taper on the mixture screws may be different from OEM so the normal initial settings will be wrong. If the carb has a port for the impulse signal, it should be tested to hold pressure and vacuum. If the carb has a port for a remote "primer" bulb, plug the fuel inlet port and apply a vacuum to the primer port, if it holds a vacuum, both check valves (body and nozzle) are good. If the carb passes these simple tests, you probably have a good one. Put a drop of oil on the ends of both shafts and bolt it in to see if the choke and throttle match.

I DO NOT buy AM ignition modules anymore.

 

[Vintage Engine Repairs]

I know a pressure/vac test is not something that should take that long, the problem is sealing everything off like the intake and the exhaust especially when you don’t have the right tools for it. Took me a while to get that figured out. Also I’ve never done it before and this is the first full top and bottom end rebuild I’ve done on a saw so I’m still learning a bit.

Have a watch of this video I made, hopefully it will help you out!

 

[singinwoodwackr]

I put an aftermarket carb on an 028 Super for a friend last week. It had been in the shop for a while since I usually buy three at a time.

Idled fine. But, it was too lean on high side. So, I turned a 1/4 turn richer. Nothing. Another 1/4 turn . Nothing. 1/2 turn, still 14, 000 or better. I was about to throw it in the trash, and opened it up like another full turn. Pig rich.

So, the high needle actually did it's function about 3 turns, maybe more, out and worked fine.

It's a little rich to bash Chinese made carbs when they are all made there.

QC not as good I'm sure but, I seem to have good luck with them.

Buy about 5 at a time for BR500,550,600,700. Five at a time for FS90's FS85's FS91's .

Doesn't mean you didn't get a bad. Doesn't mean rebuilding the old one is a bad idea .

I have found that on other, even oe, China carbs. Book settings are useless with some. Sometimes 2 1/2-3 turns does the trick. Weird…