MS201t Problem

[lone wolf]

Have done that with no change in pull.

Is there anything, that could cause this problem, with the intake manifold, or carburetor?

Carb could do it by flooding the cylinder and hydro locking it.

 

[lone wolf]

To be clear you had the clutch completely off and the same results?

 

[Ddogwood]

To be clear you had the clutch completely off and the same results?

To be clear, I pulled the bar, chain and clutch. only to have the same result. Hard pull.

As for hydro locking: I pull the plug and there is no excess fuel coming from the spark plug hole, if I turn the saw upside down. As a matter of fact, there is no gas coming out of the hole.

Lone Wolf....I just want to thank you for your continuing interest in helping me to solve this issue. I really appreciate your suggestions and find that you and I are on the same page. This is a head scratcher that I have never come across in the hundreds of chainsaws that I have repaired. I am beginning to think that the MS201T has some design flaw that makes this saw a lemon. I keep reading that it is underpowered to begin with, hence all the modification articles that are prominent on the net.

Of note: Having limited experience with the MS201T, I did notice that of the two saws that I have had apart, the the piston arm seems to float around on the crank quite freely ( a bit more than I would expect). Also (and maybe related to this "looseness") that of the many times that I have pulled the head off this saw to make sure that I have oriented the piston and rings properly, and have re-installed the cylinder head; I have, then, installed the flywheel, and spun the engine just to check the motion of the piston running through its cycle (without the spark plug in) . What I have noticed is that engine rotation is not smooth. That every time that the piston approaches, and passes, top-dead-center, it gets a bit harder to turn, and then "Clunks" past the top of its stroke. There is no compression..the head is open, via no spark plug!

Once the saw is completely re-assembled (and without the spark plug installed), I pull on the pull-starter slowly, to check the motion, or rotation of the engine, and have the same result. That is, as the piston approaches TDC it gets stiffer, and then, "Clunks" past TDC, and then gets easier until the piston, once again, approaches TDC. Put the Spark Plug back in (and the saw has compression), the "Stiffness & Clunk" are exacerbated by X 20 fold! This is the problem. The saw is extremely hard to pull right before the rotation hits TDC until it just passes TDC. The saw pulls easily through the rest of the rotation.

It is like the saw could almost get stuck right at TDC under the right circumstances. But, once the saw is running, the momentum of the engine rotation easily pushes the piston and piston arm past TDC.

Does that make any sense to you? Is this a design flaw?

Ddogwood

 

[lone wolf]

To be clear, I pulled the bar, chain and clutch. only to have the same result. Hard pull.

As for hydro locking: I pull the plug and there is no excess fuel coming from the spark plug hole, if I turn the saw upside down. As a matter of fact, there is no gas coming out of the hole.

Lone Wolf....I just want to thank you for your continuing interest in helping me to solve this issue. I really appreciate your suggestions and find that you and I are on the same page. This is a head scratcher that I have never come across in the hundreds of chainsaws that I have repaired. I am beginning to think that the MS201T has some design flaw that makes this saw a lemon. I keep reading that it is underpowered to begin with, hence all the modification articles that are prominent on the net.

Of note: Having limited experience with the MS201T, I did notice that of the two saws that I have had apart, the the piston arm seems to float around on the crank quite freely ( a bit more than I would expect). Also (and maybe related to this "looseness") that of the many times that I have pulled the head off this saw to make sure that I have oriented the piston and rings properly, and have re-installed the cylinder head; I have, then, installed the flywheel, and spun the engine just to check the motion of the piston running through its cycle (without the spark plug in) . What I have noticed is that engine rotation is not smooth. That every time that the piston approaches, and passes, top-dead-center, it gets a bit harder to turn, and then "Clunks" past the top of its stroke. There is no compression..the head is open, via no spark plug!

Once the saw is completely re-assembled (and without the spark plug installed), I pull on the pull-starter slowly, to check the motion, or rotation of the engine, and have the same result. That is, as the piston approaches TDC it gets stiffer, and then, "Clunks" past TDC, and then gets easier until the piston, once again, approaches TDC. Put the Spark Plug back in (and the saw has compression), the "Stiffness & Clunk" are exacerbated by X 20 fold! This is the problem. The saw is extremely hard to pull right before the rotation hits TDC until it just passes TDC. The saw pulls easily through the rest of the rotation.

It is like the saw could almost get stuck right at TDC under the right circumstances. But, once the saw is running, the momentum of the engine rotation easily pushes the piston and piston arm past TDC.

Does that make any sense to you? Is this a design flaw?

Ddogwood

Maybe the rod bearing is seized or the cyl is made wrong send me the damn thing and I will get to the bottom of it. You missed something . I wonder if the crank is bent? Whats the history was it dropped out of a tree?

 

[Ddogwood]

Maybe the rod bearing is seized or the cyl is made wrong send me the damn thing and I will get to the bottom of it. You missed something .

But, it did the same thing before I installed the new piston and cylinder and crank case assembly. In other words, different rod bearing and different cylinder. but, same problem.

 

[lone wolf]

But, it did the same thing before I installed the new piston and cylinder and crank case assembly. In other words, different rod bearing and different cylinder. but, same problem.

Want to call me Ill pm you

 

[Ddogwood]

Want to call me Ill pm you

I'm sorry. I had to check out for awhile, So I have just read your message. I don't mean to sound too rookie here, but what does PM mean?

 

[Ax-man]

Personal message or e-mail that you and wolf can have a private conversation here on the site.

 

[lone wolf]

Personal message or e-mail that you and wolf can have a private conversation here on the site.

He's calling me later today.

 

[lone wolf]

I'm sorry. I had to check out for awhile, So I have just read your message. I don't mean to sound too rookie here, but what does PM mean?

Received your PM waiting on the call.

 

[Ketchup]

Dumb thought: is your spark plug too long?

 

[Ax-man]

That is not a dumb thought . Just about every saw I come across has the wrong plug in them .

 

[Nathan Graff]

Is the piston just kissing the top of the cylinder?

 

[SCHallenger]

I have an early 201 (rear handle), so I'm following this thread with much interest! Mine is anything but underpowered. It is very strong for a 35cc saw. It has had a MM & a timing advance & has also had the original 13,300RPM limited coil replaced with the newer 14,000RPM version which did nothing for the performance, but made it easier to tune.

I hope you get the problem sorted out. Kudos to you for sticking with it!!

 

[PV Hiker]

I have not heard yet that the coil gap is correct? Too small, the flywheel magnet drag on the pickup?

 

[Ddogwood]

G

Is the piston just kissing the top of the cylinder?

Good thought, but no it is not.

Ddogwood

 

[Ddogwood]

I have not heard yet that the coil gap is correct? Too small, the flywheel magnet drag on the pickup?

Good thought, but not the issue. Thanks
Ddogwood

 

[Ddogwood]

Dumb thought: is your spark plug too long?

Not a dumb thought at all. But, I do have the correct plug in it and it is not hitting the piston.

Thanks, Ddogwood

 

[rupedoggy]

I didn't really read all of this but have you tried to pull the saw over with the ignition OFF?

 

[lone wolf]

I didn't really read all of this but have you tried to pull the saw over with the ignition OFF?

It rolls over easy when the plug is out so it isn't the ign.