Stihl 066 exhast port question

[379 pete]

Hi, I just put togather an 066 red eye, using a newer MS660 cylinder and piston, The service book called attention to the fact that the later cylinder has a wider exhast port, and requires a late model muffler, that makes sense, but the muffler port gasket they recommend #1125 149 0601 is the same as for the older 064 and 044, This causes a restriction of close to 3/16" between the jug and muffler. Surely the engineers were smarter than that. Was it for a reason??? I filed the gasket to fit the port and muffler, and the saw preforms like a champ !!! Any ideas on this out there???

 

[KurtFromJersey]

I'm waiting on a new cyclinder head for my 66 now. Did you use the old muffler or did you buy a new one.

 

[Tree Sling'r]

Hi, I just put togather an 066 red eye, using a newer MS660 cylinder and piston, The service book called attention to the fact that the later cylinder has a wider exhast port, and requires a late model muffler, that makes sense, but the muffler port gasket they recommend #1125 149 0601 is the same as for the older 064 and 044, This causes a restriction of close to 3/16" between the jug and muffler. Surely the engineers were smarter than that. Was it for a reason??? I filed the gasket to fit the port and muffler, and the saw preforms like a champ !!! Any ideas on this out there???

Sounds like you already did it. Take a Dye grinder, pencil grinder, Dremel, file or what ever you have and match it up so it matches your cylinder and muffler. Same thing needs to be done on any sort of muffler mod.

 

[Lakeside53]

3/16?? I've never seen anything like that.. I have an MS660 cylinder and it fits the 1125 gasket fine.

Where is the service manual does it tell you about the muffler issue?

 

[379 pete]

Hi, I read it in the engine repair section, dont have the manual here, but i can get the page number. Yes the exhast port was at least 3/16 longer than the gasket hole, and it looked like it was made that way, All I know is it made one scream'in machine.

 

[379 pete]

Its on page 25 of the 064 - 066 service manual, you need an adapter plate to use an older muffler on the newer cylinder, because the port is longer, but the same gasket is used in all of them.

 

[Lakeside53]

I'm wondering if either the cylinder was modded or you were given the wrong gasket..

 

[379 pete]

The port looks factory, and the gaskets line up perfectly with the 064 port, 044, 064, 066, and MS660 all use the same number gasket according to the books???

 

[Lakeside53]

Its on page 25 of the 064 - 066 service manual, you need an adapter plate to use an older muffler on the newer cylinder, because the port is longer, but the same gasket is used in all of them.

I found it... They actually say you need the adapter to make the NEW muffler fit the old cylinder... and that you can't use the old muffler with the new...

They are not taking about width of the opening.. but the the DEPTH of the cylinder and how it affects the muffler. The newer muffer is less deep. The 064 needed a spacer flange on some muffler/cylinder combinations, and it uses the same crankcase as the 066 red-light.

I know the new muffler and gasket fit nicely up to the new cylinders, and I have used the adapter (spacer) flanges when fitting newer mufflers.

 

[379 pete]

Could be I got a freek cylinder, All I know is I like it !!! The old red eye will out cut my MS 660, I also put a NEW 660 carb on the old bugger!! with the thin base gasket, Got to spend the $18.00 for a compression release though, its a bear to pull over.