Echo 620p FKWS Build

[Catfishclark89]

Oh man this talk about fitting a 460 top end!!!

 

[farminkarman]

Oh man this talk about fitting a 460 top end!!!

You know what is better than talk?

 

[huskihl]

You know what is better than talk?

It got a little high strung once it broke in

 

[Catfishclark89]

It got a little high strung once it broke in

For sale?

 

[farminkarman]

For sale?

I’m guessing not

 

[EFSM]

Didn't @Red97 do one of them? If I recall correctly, it put out 9 hp to the stock 4.5 hp.

 

[farminkarman]

Didn't @Red97 do one of them? If I recall correctly, it put out 9 hp to the stock 4.5 hp.

I think he did more than one. I’m pretty sure he was involved with the one Kevin ported for Cole too.

 

[huskihl]

For sale?

I don’t believe so. Get a hold of Joe, Red97 on here. He might be willing to weld up another cylinder and muffler so it will fit

 

[farminkarman]

Back to this 620… I got the jug zeroed out, and then set my compound for ~11 degrees. I had to eyeball a bit because my scale doesn’t go that far.

 

[farminkarman]

I cut 0.030” from the band. I didn’t want to go any further as the plating on the jug didn’t go all the way to the band as it was.

 

[farminkarman]

Cutting the base.

 

[srcarr52]

View attachment 428173View attachment 428174Back to this 620… I got the jug zeroed out, and then set my compound for ~11 degrees. I had to eyeball a bit because my scale doesn’t go that far.

Thats a proper boring bar!

 

[Ketchup]

View attachment 428173View attachment 428174Back to this 620… I got the jug zeroed out, and then set my compound for ~11 degrees. I had to eyeball a bit because my scale doesn’t go that far.

That’s interesting. Why 11 degrees?

Thanks for doing a build thread!

 

[farminkarman]

That’s interesting. Why 11 degrees?

Thanks for doing a build thread!

I did that to match the angle on the piston.

 

[farminkarman]

Squish measurement: When cutting an angled band, you have to check your clearance across the band as the angle may not perfectly match the piston. In this case, the squish clearance was .021” at the wall and about 0.024” at the edge of the chamber.

 

[farminkarman]

For you saw nerds following along, here are the timing numbers after the machine work:

EX: 112
TR: 132
IN: 82

 

[srcarr52]

Squish measurement: When cutting an angled band, you have to check your e across the band as the angle may not perfectly match the piston. In this case, the squish clearance was .021” at the wall and about 0.024” at the edge of the chamber.
View attachment 428185

I usually chuck the piston in the 3 jaw and use a test indicator on it's crown to dial in the compound so it gains about 0.003-0.004" towards the chamber side vs. the cylinder wall side.

 

[farminkarman]

I measured the exhaust port width stock at 24mm.

I usually chuck the piston in the 3 jaw and use a test indicator on it's crown to dial in the compound so it gains about 0.003-0.004" towards the chamber side vs. the cylinder wall side.

That is a good idea!

 

[farminkarman]

The stock exhaust port measured in just shy of 24mm.

 

[farminkarman]

Here is where I’m gonna take the exhaust: Again, for you two-stroke nerds, that black line for the roof is at 103 degrees.