porting Stihl 361 pros and cons

[smith2bj]

Is there a web site that has a step by step with pictures that is easy to follow along with?  I tend to be a visual person that needs to see it done.   

[smith2bj]

does anyone know about a website that discribes how to port a muffiler on the stihl 361 that they would recomend?

[boobap]

this one right here...what else do you need?   

[windthrown]

All the EPA regulations requiring saw makers to make the saws run super lean with ultra high exhaust temps will make the saws last forever. Removing those exhaust restrictions and providing the saw with adequate fuel and lubrication will cause the saw to burn up quicker. 

I hope that this was posted tongue in cheek...

Ported saws will typically run better, richer, cooler and last a lot longer. Lean saws that run hotter are sure to burn up faster. Ported saws burn more gas, but that's the price you pay for having more power. They can be louder, but they do not have to be that much louder (if they are done right). As someone else posted above, a larger ports in the muffler does not always mean a better running saw. They need to be done right.

I have found that the shark-gill 361 mod is the easiest. Cut three 1/2 inch slots in the muffler on the side opposite the factory port. Then lever them open with a screwdriver. Add a piece of spark screen, and cover it with a Husky muffler port cover to baffle the exhaust toward the front of the saw. Drill 2 small holes in the baffle cover tabs top and bottom and the muffler and secure it with two small pan head screws. Then remove the limiter tabs on the carb, and open up the H jet and tack it to about 14,500 RPM WOT. It should burple (4-stroke) at WOT. Check the plug after runnig it WOT in a good long cut. The plug should be chocolate brown.

[Rocky_J]

Yes, tongue firmly planted. I'm just sick and tired of trying to convince the naysayers who will beat you to death with their doubts. So I play Devil's advocate and argue their position to show them how ridiculous it is.

[Al_Smith]

  Discussing ported saws can get as controversial as what kind of mix oil to use and at what ratio .

You can fiddle with the muffler and call it ported .You can pull the base gasket and call it ported .Fact is you can go nutty like a few of use and dome the piston,cut the base widden and raise the ex ,widden the transfers ,enlarge the intake and call it what ever you choose to . No matter what you do if you do it correctly and have the correct fuel mixture it isn't going to fly apart like a dollar watch . Chances are really great in addition to all that ,that the saw will last just as long as a factory tuned choked down stocker .------But they aren't for everybody .

[windthrown]

I dunno... once you run ported saws, all you want to do is open up all the stock saws you get your hands on.

I just modded another Stihl 310. Took an hour to do it all; opened up the muffler to match the 'standard' 1127 muffler that they sell in Europe and pretty much matches the stock carb. Then I clipped the carb H limiter and tuned the H screw around to 1-1/4 turn (stock is 3/4 of a turn). What a difference that made. The 310 keeps up with my 361s. The only difference now is the WOT revs; the clamshell 310 engine has a max rev rating of 13k, whereas the 361 is 14k. I run them at 13.5k and 14.5k (factory setting tolerance is +/- 500). Not much else you can do to 'port' a clamshell engine. Cannot squish it, maybe open the intake and exhaust ports a bit. But even with just a muffler mod it has a 10-15% gain in power. Now it has more power than a 390. It runs a 25 inch bar now, no problem. The stock 1127 saws are certainly choked down. They are gasping for air and tuned way too lean!