Mastermind Meets The Echo CST-610EVL

[hdbill]

I didn't comment because I hated to out Tom about his Sybian riding. :msp_wink:

I thought it was for rodeo practice

 

[LowVolt]

P.S. Just so long as Belgian doesn't change his avatar, life is good ....

Agreed!

This is going to be a very interesting build. I cant wait to see the vids.

 

[Adirondackstihl]

izza:izza:.............. one for each cylinder

 

[Rudolf73]

izza:izza:.............. one for each cylinder

+ :beer::beer:

 

[Mastermind]

I got all four of the av bushings squared away and checked port timing and squish. Both jugs are spot on.....

EX: 109
TR 121
SQ .021

 

[Sprintcar]

Both jugs are spot on.....

What, where, when? There fixed it for ya!

 

[Mastermind]

What, where, when? There fixed it for ya!

The jugs Jerry.......it's all about the jugs ya know. :msp_thumbup:

 

[GBD]

I got all four of the av bushings squared away and checked port timing and squish. Both jugs are spot on.....

EX: 109
TR 121
SQ .021

Well, that is a lot of transfer duration on a 30`ish cc cylinder! :msp_ohmy: As I remember from the times I used to port a lot of string trimmers, 127* to 130* depending on port withs, would be more like it on a 30 cc cylinder. :msp_thumbup:

 

[blsnelling]

I got all four of the av bushings squared away and checked port timing and squish. Both jugs are spot on.....

EX: 109
TR 121
SQ .021

Those are some crazy numbers. Only 12° of blowdown!

 

[blsnelling]

How in the world do you plan to work inside that tiny cylinder? My right angle hand piece is pretty snug in a 50cc.

 

[Mastermind]

Those are some crazy numbers. Only 12° of blowdown!

I agree.

It has a domed piston crown as well. I've figured out how to cut the squish in those though. I intend to take enough out to allow me to raise the exhaust, still have good solid compression, and gain some blowdown.

I'm not planning on going over 170 on compression on this one though. A crankshaft weakness has been mentioned before and there are no decompression valves.

 

[GBD]

I agree.

It has a domed piston crown as well. I've figured out how to cut the squish in those though. I intend to take enough out to allow me to raise the exhaust, still have good solid compression, and gain some blowdown.

I'm not planning on going over 170 on compression on this one though. A crankshaft weakness has been mentioned before and there are no decompression valves.

Those small cylinders are very easy to overport because of small volume to wall area relationship.

 

[Joe Kidd]

How in the world do you plan to work inside that tiny cylinder? My right angle hand piece is pretty snug in a 50cc.

I'm giving the chimp the benefit of the doubt!

 

[RVALUE]

How in the world do you plan to work inside that tiny cylinder? My right angle hand piece is pretty snug in a 50cc.

dental tools

 

[Mastermind]

dental tools

I missed Brad's post till you quoted it. I won't be doing anything in the transfers and just working on the exhaust port can be done from the outside.....

 

[thomas1]

dental tools

Not available in Tennessee.

 

[Joe Kidd]

Not available in Tennessee.

Do you know that the toothbrush was invented in "The state of your choice goes here" That's right. In any other state it's called the "Teethbrush"

 

[Ambull]

Wow that's one heck of a project. I am quite interested to see how you do. I have one of those 610 POS's and I can't stand using it, for its lack of power. If this one turns out good you will be seeing another in the near future.

To respond to an earlier post, the pistons move in exactly the opposite direction of each other, thus cancelling each others motions out. The crank needs no counter balancing. Because they fire at the same time, they can be run with one carburetor and one coil. A very smooth running saw.

 

[Mastermind]

Wow that's one heck of a project. I am quite interested to see how you do. I have one of those 610 POS's and I can't stand using it, for its lack of power. If this one turns out good you will be seeing another in the near future.

To respond to an earlier post, the pistons move in exactly the opposite direction of each other, thus cancelling each others motions out. The crank needs no counter balancing. Because they fire at the same time, they can be run with one carburetor and one coil. A very smooth running saw.

I'm thinking it should be much better......I do wish I could have used it enough to get a "feel" for what was lacking.....

 

[Adirondackstihl]

opcorn: