What's wrong with the MS661?

[Wilhelm]

I think the go the 661cm to 660 route is that's what they can get there hands on here in the states.

That makes sense.

 

[Coltont]

Ive had 2. First one had every issue that's been discussed in this thread. The dealer replaced it with a new saw. Its good. Have one redfin ported. I converted it to a wj69 and it's been bulletproof. To be honest though, id never buy another one. Ran 660s in the woods for 8 years they are a much better saw in my opinion. I'd buy a 390xp over a 661.

 

[460 magnum]

.

I modded the air filter cover on the bottom to let chips out. Now I use the max flow filter and have modded the MF cover on the bottom to let chips out.

Do u have any videos or pictures on how u modded the cover?

 

[CR888]

The 066/660 chassis came out in the late 80's and hung around for a quarter of a century changing along the way so don't worry folks by 2040 the 661 will be a good saw...

 

[RI Chevy]

Bah humbug!

 

[blacksmith]

What is the verdict on these door stops when they get converted to non-CM?
Do they stop misbehaving?
Is the power output similar or better than on a CM unit?

@jmester had one and gave up on her.
I don't know what issues his had, maybe he'll chime in.

Considering the premium Stihl charges, whatever issue the 661CM has should have been fixed a long time ago!

As for mine, one word AWESOME! I think it runs better since it switched it to non-mtronic! But that's just me. I may or may not have done the same thing that you have in mind. Let me know what you have in mind to mke it non-mtronic.

 

[odin]

As for mine, one word AWESOME! I think it runs better since it switched it to non-mtronic!

Is the swap as simple as it sounds? Any modifications needed to fit the 660 flywheel and carb?

 

[blacksmith]

Is the swap as simple as it sounds? Any modifications needed to fit the 660 flywheel and carb?

It actually wasn't too bad. I am not very good with saws by any means no expert! But if I am able to do it anyone can.

The flywheel very minimal modding and carb no modding at all, very easy! The coil is what takes some time and a little bit of playing around. I've had mine together and apart so many times because I thought I was doing something wrong, gap not right etc. Because I had no spark! Here after I found out what the ohms readings were supposed to be and tested the coil it was a bad OEM coil! That sucks because I couldn't take it t back because I had modded the coil. So I ended up buying a $20 coil off of ebay which actually is a slightly different shape and fit in better. I tested this one before I modded it just in case but it was ok.

Always starts in one to 3 pulls every time and runs really well. I actually think that it runs better than when it was M-tronic!

 

[blacksmith]

Is the swap as simple as it sounds? Any modifications needed to fit the 660 flywheel and carb?

If your serious about doing this PM me for more info!

 

[dustinwilt68]

I trust Kevin's opinion as he has ran them all, stock and ported, so I think I will just keep my 394/395 if for no other reason then they are cheaper to buy and parts down the road.

I've had a few ......... still have 2 since brand new
Most issues I've seen are the harnesses need soldered at every connection. My oscilloscope showed me the intermittent issue a few years back on someone elses saw. Didn't upgrade anything and that saw is still cutting today, that one has the original intake too.

Max flow is a MUST ............ so too is a muffler mod.

• They run even with any 394/395, each one, ported against ported or not ported at all

 

[hseII]

I think all the modern AT/MT saws have had a period where bugs have been ironed out, upgraded parts etc. It appears those who choose to understand the tech are the ones with the most reliable saws...lol.

MTronic, yes.

No so on the A/T.

FWIW.

 

[Redbull661]

Do u have any videos or pictures on how u modded the cover?

check this post out - http://opeforum.com/threads/show-me-your-air-box-mods.8063/page-2#post-722578

here are some more... see attached files

 

[460 magnum]

check this post out - http://opeforum.com/threads/show-me-your-air-box-mods.8063/page-2#post-722578

here are some more... see attached files

Thank you

 

[huskyboy]

check this post out - http://opeforum.com/threads/show-me-your-air-box-mods.8063/page-2#post-722578

here are some more... see attached files

Nice mod. I remove the rubber flap on air filter cover and take out the slide up top for summer use. Can put it back for the winter if needed, clips in and out. I think it seems to help as well.

 

[Redbull661]

Nice mod. I remove the rubber flap on air filter cover and take out the slide up top for summer use. Can put it back for the winter if needed, clips in and out. I think it seems to help as well. View attachment 140069 View attachment 140071

by removing the black slide from the top you are drawing in hot air into the air filter from the engine. Per Scottie too Hottie you wouldn't even do this in the winter. Because the saw runs better on cold air. The only time you'd only want to remove that slide would be if you were having carb icing.


removing the black flap thingy - is a great idea because it traps the hot air from the engine and shuttles it into two places. 1. if you remove the black slide. 2. at the bottom of the air filter cover on the flywheel side.

 

[huskyboy]

by removing the black slide from the top you are drawing in hot air into the air filter from the engine. Per Scottie too Hottie you wouldn't even do this in the winter. Because the saw runs better on cold air. The only time you'd only want to remove that slide would be if you were having carb icing.

The black rubber flap part seals against the cylinder head cover and directs the hot air in. Without it there, it doesn’t get directed into the saw intake. Less chips on the filter without it there (they come off the cylinder then directed around intake flange ). I can always put it back if I notice ill effects, but I haven’t yet on 461/661. The max flo removes that rubber flap, so in theory it too would be directing in hot air according to your theory.

 

[460 magnum]

The black rubber flap part seals against the cylinder head cover and directs the hot air in. Without it there, it doesn’t get directed into the saw intake. Less chips on the filter without it there (they come off the cylinder then directed around intake flange ). I can always put it back if I notice ill effects, but I haven’t yet on 461/661. The max flo removes that rubber flap, so in theory it too would be directing in hot air according to your theory.

Just get the max flo

 

[Redbull661]

Have you tested that? The black rubber flap part seals against the cylinder head cover and directs the hot air in. Without it there, it doesn’t get directed into the saw intake. Less chips on the filter without it there (they come off the cylinder then directed around intake flange ). I can always put it back if I notice ill effects, but I haven’t yet on 461/661. The max flo removes that rubber flap, so in theory it too would be directing in hot air according to your theory.

I was adding to my above post as you posted this. Again taking the black flap is a great idea for exactly the reasons you stated.

That is the slide's purpose(to draw in hot air from the engine).(see attached pic from manual).

Yes that is a problem with the max flow IMO. However I have tested the max flow with MF cover on vs just the HD2 and it was still faster a decent margin.

Another issue with the HD2 is that you must leave the spit back cap in place or the spit back will soak and hurt performance of HD2 quite a bit. You can take the spit back cap out (less air restriction) with the max flow.

 

[huskyboy]

I was adding to my above post as you posted this. Again taking the black flap is a great idea for exactly the reasons you stated.

That is the slide's purpose(to draw in hot air from the engine).(see attached pic from manual).

Yes that is a problem with the max flow IMO. However I have tested the max flow with MF cover on vs just the HD2 and it was still faster a decent margin.

Another issue with the HD2 is that you must leave the spit back cap in place or the spit back will soak and hurt performance of HD2 quite a bit. You can take the spit back cap out (less air restriction) with the max flow.

I was eyeing that spit back thing, it did look sort of restrictive. I bet remove that, a mm and max flo make a big difference alone?

 

[Redbull661]

all the mods add up. just depends on how far down the rabbit hole you wanna go.