Echo 6700 build

[Red97]

Clean saw. Really similar to the 670 except Air filter, Chain brake, cover, front tensioner, and color. are the main visible ques.



Small ex port, but look at the dropped floor...



This one will clean up real nice.



Might dig back into this one after a std port job. Be really easy to adapt a large carb/boot, not planning to at this time.



This has me kind of baffled. No base gasket/ sealer at all.. nothing appears to be touched... based on the corrosion on the jug bolts. Wonder if it was like that since new? Still had plenty of comp to run and a new tygon fuel line.



Nice little chunk missing.



before



after



dual port.



Intake



Beefy connecting rod.

Sq .048
In 74, Ex 103, Tr 122.

This one is getting a 268 piston. More than likely add some bridges on the intake side, rather small tunnel,

Have to see what numbers look like with the 268 piston but I would like to see 77 101 123...

 

[redtractor]

They also came in gray, at least at the end of the model's run. Good saw. Horribly small air filter gets clogged quick making it pig rich.

 

[Backtroller]

I'm curious to see how this one performs with the 268.

 

[Red97]

They also came in gray, at least at the end of the model's run. Good saw. Horribly small air filter gets clogged quick making it pig rich.

You are correct, I have seen some 6700 with the large round filter and a taller cover. The gray ones mainly. Seems all the 670's have that filter.

Might be worth looking into swapping it. The stock filter is very small as you mentioned. But it sure is sealed up nice.

I'm curious to see how this one performs with the 268.

Me too. Should give a healthy bump in compression. Might have to track down a larger carb..

Just going by the numbers this should be a very strong saw... but it is not accredited as so.

Gotta be in the carb/muffler.

Another thing I noticed on this one is all torx fasters. Figured that would have been on the newer models. But the 670 was all Allen bolts.

 

[backhoelover]

does that model have the cdi coil on it

 

[backhoelover]

also how did you clean up cylinder looks damn good

 

[Red97]

does that model have the cdi coil on it

This one. only clean, sorry not up on coil terms. Same as the 670 coil

also how did you clean up cylinder looks damn good

Thank you

Sandpaper on a split mandrel . Started with 150, 220, 320 then finished with 400 scuff pad.

 

[backhoelover]

not a cdi. cdi units have 2 piece coil

 

[Red97]

268 piston fitted. Had to open it up a bit to fit the rod. Smooth out the casting scale while I was at it.



Band cut, squish at .021 around .050 out of it..

Just by swapping the piston numbers are 81, 110, 131.



Transfers widened just a bit, clipped the bottom edge. Set at 123



Ex set at 101, just a bit wider too.

This one may end up with a little too much compression. ..

 

[backhoelover]

what about the older one in the above pics

 

[awol]

I ended up chamfering the edge of the squish band on the one I did, to get compression down. Your numbers look pretty good. If this is like the 670 with its small carb bore, it'll like the high intake duration.

 

[Backtroller]

Very nice work. You might have to throw on the bigger carb just to see what it can do. Looking forward to seeing this one run.

 

[Red97]

not a cdi. cdi units have 2 piece coil

what about the older one in the above pics

Same coil, on both saws, just didn't have a pic of it installed on the 6700

Very nice work. You might have to throw on the bigger carb just to see what it can do. Looking forward to seeing this one run.

I have a cs 8000 carb to go on. Won't be anything for 9 days. Lol going on vacation.

 

[Red97]

I ended up chamfering the edge of the squish band on the one I did, to get compression down. Your numbers look pretty good. If this is like the 670 with its small carb bore, it'll like the high intake duration.

I seriously thought bout that. But have 2 more to go. See which one does better with different bars. Only if this one starts having running issues, I will drop the comp.

This saw has tiny ports all the way around. Every one is under 50%.

I do like the round ring in the intake, be pretty easy to bore that out and stick in a larger one that fits a 372 boot/carb. Not sure if the exhaust could handle it.

You have any idea what they were thinking dropping the floor of the ex like that?

 

[awol]

It's always easier to loose compression, than it is to gain!

The dropped floor must simply be for an improved exit angle?

 

[Backtroller]

About time you take a vacation!

I like these non mainstream builds, but we can all wait to see the results.

 

[Red97]

It's always easier to loose compression, than it is to gain!

The dropped floor must simply be for an improved exit angle?

Very true.



Here is the 670 exhaust upside-down.



6700 shares the same gasket. Would that dip help scavenging?
Venturi effect?

Thank you for the help sir.

 

[awol]

In my mind the dropped floor would just let the ex flow travel a more relaxed path on its way out, kinda like how we round off all corners on the lower trans when porting.

 

[drf256]

Any reason you can't take .020 off the piston and only .030 form the chamber next time Joe?

Should give you a higher ex roof before porting as well.

I use a carbide ball to open the chamber/SB junction sometimes. Gotta just watch the plug threads. A scotchbrite ball smooths it all out.

Does your plug clear your piston?

 

[Red97]

Any reason you can't take .020 off the piston and only .030 form the chamber next time Joe?

Should give you a higher ex roof before porting as well.

I use a carbide ball to open the chamber/SB junction sometimes. Gotta just watch the plug threads. A scotchbrite ball smooths it all out.

Does your plug clear your piston?

Yeh taking some off the piston could be an option.

This piston added 7* to the ex, could probably use that program @David Young uses for liner measurements to find the exact height change.

Jug isn't sealed yet, may angle the cutter on the mandrel and narrow the band/open the chamber. Just got one of those scotchbrite balls.

Kind of curious to see where the comp ends up as is, if it becomes an issue I can always go back in. Should have 5-8* of exhaust height left before breakthrough.

Maybe take exhast high and fit a pipe

Plug should clear, if not I can get some washers or divot the piston lol.