Problematic MS661

[blsnelling]

Zama...

Oh no! Surely not! Lol.

 

[nitehawk55]

Wasn't there an issue with the fuel puddling in the 661 manifold and they changed it ?

 

[Andyshine77]

China is my guess as well, just look at the quality of today's carb's vs the older ones. Poor castings, machining and fitment.

 

[blsnelling]

Wasn't there an issue with the fuel puddling in the 661 manifold and they changed it ?

This perfect running 661 has the intake with the bellows and rubber washers inside it.

 

[Andyshine77]

Zama...

Zama = Stihl.

 

[mcobb2]

Zama = Stihl.

Yes it's owned by Stihl but still manufactured in Riceland...

 

[Andyshine77]

Yes it's owned by Stihl but still manufactured in Riceland...

Yes and I bet many other parts on Stihl and husky saws are made there.

 

[mcobb2]

Look under the FS 38... I used to rip the stickers off. Hurt my fingers so I just quit promoting them. Sticker says "Made by Stihl in China" or something really close to those lines.

 

[David Young]

Brad,
I think you have a great scientific method going on here, nice job.
the thing I may offer to you while you are looking for answers is this.

think a little out of the box too. could a tank vent or a marginal crank seal cause a problem, iffy base seal. just offering out of the box thoughts. likely it will be in the carb itself that seems the most likely.

 

[procarbine2k1]

Zama = Stihl.

There is more to it than that. I can't remember the details, @Definitive Dave explained it to me a few weeks ago.

 

[Trx250r180]

It was pointed out to me by a fish once that i bought a chinese knockoff of a chinese made zama carb ,so the chinese are making knockoffs of their own product now .

 

[blsnelling]

think a little out of the box too. could a tank vent or a marginal crank seal cause a problem, iffy base seal. just offering out of the box thoughts. likely it will be in the carb itself that seems the most likely.

Great point. I've considered the possibility of an air leak. You wouldn't expect it on such a new saw, but stranger things have happened.

 

[procarbine2k1]

It was pointed out to me by a fish once that i bought a chinese knockoff of a chinese made zama carb ,so the chinese are making knockoffs of their own product now .

Zama also makes carbs without their name cast in them, if it infringes on an agreement they have standing with a manufacturer. I normally don't buy a lot of AM parts, but the AM carbs I have seen and used have been great.

 

[blsnelling]

Next I have to determine the source of the problem. Since his is running perfectly, I'm thinking I'll put my parts on his saw, one at a time.

The more I think about this, the more I think I'll put all the mods back on my saw and work from there. The first thing I'm going to do is a pressure/vac test. After that, I'll swap the complete carb, and go from there.

 

[David Young]

its yours to do what you want with, my thought is to continue putting parts on the good saw until its not good any more. sometimes while tearing it apart you find the fly in the ointment remember your solo twin with the backward piston.

i know it it a new saw and should't have issues but. its there and real.

 

[7sleeper]

Pop up piston....








7

 

[blsnelling]

Pop up piston...

7

You know it! Very efficient and totally effective 95% of the time.

 

[nitehawk55]

Have a close look at the throttle plates on both carbs and see if there is any difference in them . My husky dealer had a 562 that was bogging and the throttle plate design was a bit different in the new one and it fixed the problem .

 

[blsnelling]

Have a close look at the throttle plates on both carbs and see if there is any difference in them . My husky dealer had a 562 that was bogging and the throttle plate design was a bit different in the new one and it fixed the problem .

Will do. They made a LOT of changes to the 562 carb! I think it took them four tries to finally get it right.

 

[nitehawk55]

Will do. They made a LOT of changes to the 562 carb! I think it took them four tries to finally get it right.

Yes it did and the Stihl MS 200T too !