first go at porting on my 660.

[breymeyerfam]

this afternoon was disassembly and everthing looks great. squish without gasket is between .020-.021. only thing holding me back is a carbide burr bit (.125 shaft and roughly .250 cutter with radiused nose). any suggestion to where to get one retail without having to order online? anyway here is some pics. the plan is just widening the exhaust and intake ports and running without a base gasket. while im at it, i see most say to use yamabond, but where do I get it, and which compund do I use? is there a comparable permatex or loctite product?

 

[pioneerguy600]

this afternoon was disassembly and everthing looks great. squish without gasket is between .020-.021. only thing holding me back is a carbide burr bit (.125 shaft and roughly .250 cutter with radiused nose). any suggestion to where to get one retail without having to order online? anyway here is some pics. the plan is just widening the exhaust and intake ports and running without a base gasket. while im at it, i see most say to use yamabond, but where do I get it, and which compund do I use? is there a comparable permatex or loctite product?

Looks like you have a real good P&C to start out with, your porting plans seem solid also. Dual port your muffler along with the woods porting and that 066 will really come to life. I use permatex copper to seal my cylinder to base and have not had a leak in that area for more than 10 years of using it.
Pioneerguy600

 

[clutch25]

You can get Yamabond at any Yamaha dealership. Let them know what you are using it for and the part guy should know which formula.

 

[breymeyerfam]

Looks like you have a real good P&C to start out with, your porting plans seem solid also. Dual port your muffler along with the woods porting and that 066 will really come to life. I use permatex copper to seal my cylinder to base and have not had a leak in that area for more than 10 years of using it.
Pioneerguy600

I have already 3/4" pipe modded the muffler lakeside style. i also will be opening the windows on the piston a little and smoothing everything out for better flow.

 

[Evan]

theres alot to be gained just by opening the factory muffler opening up. i dont see any reason to add a pipe,

cut the deflector off as cleanly as possible widen and raise exhaust outlet as much as the sparkscreen body will allow, then tack weld the deflector back on.

this mod would be unoticable and provide huge improvent in exhaust flow. i think one exhaust outlet is better than two. i cant see two outlets helping the scavenging affect any.

my reply is more for readers who havent already done the lakeside mod

after makn this reply i did some research and looked around the net for pics of 066/660 mufflers, first thing i saw is there is a huge gain to be had right through the factory exit port.
second thing brought up a question. is the chamber right off the exit port comeing from the cylinder for sound reduction or is this to improve scavenging. being me i think id gut this chamber out and make a huge gain through the factory exit port.

i also wonder wich is more work the lake side mod or modding the factory port.

lakes mod is probly slightly easier but is prone to be run without sparkscreen. the factory outlet provides a huge gain and has sparkscreen already installed.

either way is good though. i figuerd id throw my 2 cents out there and give another option to think about

 

[breymeyerfam]

no spark screen for me.

 

[Tree Sling'r]

.020-.021 w/o the gasket? Are you sure????

Gasket is .017, that would have made your stock squish .037-.038, I have never heard of a 660 with that much. .034 is the most I have encountered.

Just make sure.

 

[Bowtie]

theres alot to be gained just by opening the factory opening up. i dont see any reason to add a pipe,

cut the deflector off as cleanly as possible widen and raise exhaust outlet as much as the sparkscreen body will allow, then tack weld the deflector back on.

this mod would be unoticable and provide huge improvent in exhaust flow. i think one exhaust outlet is better than two. i cant see two outlets helping the scavenging affect any.

my reply is more for readers who havent already done the lakeside mod

after makn this reply i did some research and looked around the net for pics of 066/660 mufflers, first thing i saw is there is a huge gain to be had right through the factory exit port.
second thing brought up a question. is the chamber right off the exit port comeing from the cylinder for sound reduction or is this to improve scavenging. being me i think id gut this chamber out and make a huge gain through the factory exit port.

i also wonder wich is more work the lake side mod or modding the factory port.

lakes mod is probly slightly easier but is prone to be run without sparkscreen. the factory outlet provides a huge gain and has sparkscreen already installed.

either way is good though. i figuerd id throw my 2 cents out there and give another option to think about

I think the Lakeside mod was intended for the 341/361 type muffler. From reading his initial thread, he chose the spot because of convienance, but also because it was a hot spot in the muffler = lot of flow.

Im not saying it dont work on other mufflers, just throwing that info out there.

 

[breymeyerfam]

.020-.021 w/o the gasket? Are you sure????

Gasket is .017, that would have made your stock squish .037-.038, I have never heard of a 660 with that much. .034 is the most I have encountered.

Just make sure.

I polished the top before I did the squish check. I will recheck, what does everyone else use to check squish? I used small piece of solder in 4 spots(front back and sides) and used micrometer for check.

 

[jack-the-ripper]

I polished the top before I did the squish check. I will recheck, what does everyone else use to check squish? I used small piece of solder in 4 spots(front back and sides) and used micrometer for check.

That is how I checked the squish when I ported my 390xp. With a bead of red Permatex (no base gasket), the squish ended up at .023 & so far no problems.

 

[Tree Sling'r]

I polished the top before I did the squish check. I will recheck, what does everyone else use to check squish? I used small piece of solder in 4 spots(front back and sides) and used micrometer for check.

Sounds like you will be fine then.

 

[Trigger-Time]

Just an observation......and a maybe wrong.

Most saws I have pulled down, seems exhaust side of piston has more
wear than intake. Yours seems to have more wear on intake side.
Are you running factory HD air filter setup?

Alot of the older saws that had the old flock filters with flock missing would wear faster on the intake side of piston.

 

[blsnelling]

Every saw I pull down has more wear on the intake side at the bottom of the skirt. I find little to no wear on the exhaust side. This isn't just on my saws, but on others saws coming in for porting. Many of these are nearly new too.

 

[Sawdustmaker]

Just an observation......and a maybe wrong.

Most saws I have pulled down, seems exhaust side of piston has more
wear than intake. Yours seems to have more wear on intake side.
Are you running factory HD air filter setup?

Alot of the older saws that had the old flock filters with flock missing would wear faster on the intake side of piston.

abuse will wear the exhuast side.

Every saw I pull down has more wear on the intake side at the bottom of the skirt. I find little to no wear on the exhaust side. This isn't just on my saws, but on others saws coming in for porting. Many of these are nearly new too.

true... the saws that brad gets are not abused.

 

[blsnelling]

This is out of a nearly new 346XP and is representative of nearly every saw I disassemble.

Exhaust

Intake

 

[Wild Knight]

Don't go at it alone. IMO, you should read this thread by the wolf before removing any metal.

 

[Evan]

i could be wrong but it seems most saws brad gets are nearly new with little wear at all on them

 

[breymeyerfam]

this is what I'm calling my finished piston

let me have it, I can take it..... how bad is it?

 

[super3]

this is what I'm calling my finished piston

let me have it, I can take it..... how bad is it?

Little rough but hey it's your first attempt, go to post #16 for a pic of the "masters".

 

[breymeyerfam]

I think im going to do a final sand by hand to smooth it all out. now i just need to man up and start cutting on the jug.....