MS650/MS660 Differences

[SawTroll]

No kidding. That guy needs to find a different hobby with all of the problems he's had.

Sure enough......

 

[Gypo Logger]

If my measurements are correct the exhaust port on the 650 is 2mm higher than the 064, while the tranfers are the same at 33.5 mm.
The intake on the 064 is 60mm while the 650 is 58.5mm.
The 650 that I have has a pretty tight squish as it came from the factory, probably about 22 thou. as putting in a slightly thinner gasket would run the risk of making it a head banger.
John

 

[klickitatsacket]

If my measurements are correct the exhaust port on the 650 is 2mm higher than the 064, while the tranfers are the same at 33.5 mm.
The intake on the 064 is 60mm while the 650 is 58.5mm.
The 650 that I have has a pretty tight squish as it came from the factory, probably about 22 thou. as putting in a slightly thinner gasket would run the risk of making it a head banger.
John

If you also noticed the mujffler port is extremely tight and needs a little more blow down time before the transfers open. I believe this is why they have a higher exhaust port opening.

 

[ShoerFast]

Our Stihl distributor said some of the same things. They said it served 2 purposes. Primarily so that they could have a saw in the 85cc class, but also cause it would help them meet the EPA standards. It's all based on an average of all the saws they sell, not on a model by model basis, so if by having the 650 (which is likely a bit cleaner than the 660 just by virtue of being a a few cc's smaller) they don't sell quite as many 660's it helps them meet the EPA standards and allows them to keep the existing 660 in the lineup as is longer.

Offering both also gives manufactures a couple rocks to throw when the EPA reviews usage, demands, and projections. The manufactures don't get to say a lot, but setting the price so attractive for the 650 will tremendiously help Stihl meet there allowable EPA standards. I wonder if the 440 and 460 had somewhat the same idea behind them?

 

[Cam501]

Offering both also gives manufactures a couple rocks to throw when the EPA reviews usage, demands, and projections. The manufactures don't get to say a lot, but setting the price so attractive for the 650 will tremendiously help Stihl meet there allowable EPA standards. I wonder if the 440 and 460 had somewhat the same idea behind them?

hard to say cause the 044 predated the 046 regarding original release, whereas the 660 was around in 660 and previously 066 form well before the 650 idea was likely conceived.