066 Mag H/L Jet Adjust Post Muffler Mod...

[woodfarmer]

dual port muffler 066

is this the factory dual port being discussed, small hole on the side and the large exhaust on the front of the muffler?

 

[Lakeside53]

The drop from 7.8hp to 7.2hp occurred upon the first change of the muffler (deletion of the dual port). This muffler still had the .63 inch opening. The Second muffler with cylinder changes came later in 1998 when the muffler was dropped to .43in. with a power drop to 7.0hp. It's seems reasonable that the power loss was the muffler, and maybe not the cylinder. The cylinder may have been modified to stop the power drop being more dramatic....

I'm not seeing any HP change due to ignition coil/flywheel changes. Most of these were first to increase throttle response and ease starting conditions, then later on for emissions. Again, like with the cylinder change, as the mufflers became more restricted, the coil may be working toward keeping performance up rather than down. I have a great chart I can email anyone that wants to see the various Flywheel/coil changes over the years. Email (not PM) me if you want it.

 

[Lakeside53]

is this the factory dual port being discussed, small hole on the side and the large exhaust on the front of the muffler?

yes.... Imagine running the saw with just the smaller hole (most do)!

 

[woodfarmer]

lakeside,there is a lot of heat comming out of the smaller hole on the side, is this of any concern?

 

[Lakeside53]

lakeside,there is a lot of heat comming out of the smaller hole on the side, is this of any concern?

Not really... can brown the paint a little but doesn't seem to cause a problem. Without the dual port it's a LOT hotter.

 

[5555555]

Is there a way to tell which vintage jug you have by measuring some dimension? Maybe exahust port dimensions. I think I'vegot a couple around and I'd like to try and get a bit more out of one of my 066s that's getting tired. Looking at all options.

THanks,

Jim

 

[OilHead]

I have a 066 second generation w/ poly flywheel that is in need of a piston & cylinder replacement. Has anyone confirmed that there were in fact port timing changes made to the 1122 020 1209 kit when it was superseeded by the 122 020 1211 kit in 1998. If so is the 1209 kit still available ?

 

[Lakeside53]

The -1209 is still available. The -1211 is listed as a replacement part for the the USA Artic and Magnum wrap.

Tech note 02.98 states that the ports and timing were changed to "optimize" the combustion processa and in conjunction with the newer muffer, to allow emission standards to be met.

 

[OilHead]

OK . Cool . When I get a minute I'll take some measurements & post them from the old 066 mag cylinder . It would be interesting to see exactly where the differences are in requards to the top & bottom of the transfer heights as measured from the base in addition to the intake & exhaust.