HELP! Help with first time porting Echo 800P

[dthieme]

Yep it works fine. CS 800p or the CS 8000 isn't a real valuable or competitive saw compared to the stihls and husqs. So makes a great candidate for a woodsporting home job.

.040 thou squish, slightly widening/raising the exauhst port a sliver still gives about 160 psi. Ignition timing advance makes up the rest.

The piston windows don't match the lower transfers, so a little work there helps big time.

Besides power improvements:

Spikes are too small to safely control the saw when cuting down stumps. Handle is too small diameter for the weight and power of the darn thing. Both cheap/easy fixes.

That goofy flapper filter and stir-stick sized carburetor are the biggest things holding back these rugged cinder blocks. Both cheap and easy fixes:

Thread 'What yer cheap saw favorites?'

Jul 21, 2025

Whats your cheap saw fix?

I like runnin and wrenching on the grey cs 6700's cs 670's and cs 8000's. Quality Made in Japan parts are readily available from scores of online vendors and the saws are cheap.

They cut good, really wake up with basic mods, are easy to work on and have filthy good oilers. Manual oilers too. The round automotive style filters flow well and never let in dust.

Unlimited coils on all and ive never seen one fail.

I've milled with em and cut lots of firewood. The cs 8000 even made it's way on a paid job last year, where I had to plunge cut 32" diameter leaning...

• mainer_in_ak
• Replies: 30
• Forum: Chainsaws

• 

dthiem,
Let me know if you'd like an HDA 45 carb. I have extras. Good luck dude!

I'd be very interested in one! Can you send me a message?

 

[dthieme]

Bingo.

@huskihl Still figuring out how to use this forum. That makes sense, thanks for the advice. Do you have any recommendations on 90 degree handpieces that don't cost a fortune? Preferably one that would work with a flex shaft on a dremel.

 

[dthieme]

I've never ported a cs800p, so I don't have any specific info to share. I can make some suggestions though. For starting out, don't get carried away thinking about huge muffler mods or carbs & air filters. You can always mess with that later. Now, for the timing numbers you posted, the exhaust at 106 and transfers at 128 make sense. The intake at 146 does not, so I would double check that...I would think it would be somewhere between 70 and 80. Some Echo cylinders don't have much meat above the exhaust port window to allow raising the exhaust very much...not sure if the 800 is like that or not, so check. If the piston/ cylinder will allow for widening the exhaust to 65% of the bore diameter, that is what I usually shoot for. Sometimes ring pins, or piston skirts will not allow you to go that wide. Now for numbers....what do you want the saw to do? Do you want it to still run like a tractor, or do you want it to have some more zip? If you want the saw to still be a tractor, I would try raising the exhaust back up to 103-104 after machine work. If you want the saw to turn more rpm with a shorter bar, then maybe more in the 98-100 degree range. Depending on how wide you can make the exhaust would help decide how much blowdown to use. If you can hit 65% of the bore, then you could try 18-20 degrees of blowdown. If you are stuck at closer to 60%, then you might need to increase blowdown a few more degrees. Not knowing what the limitations are on the 800, I would guess that a decent starting point could be 101, 120, 78. As for your question on machining piston vs. raising ports, don't machine the piston. Machining the edges of the piston will eliminate "squish" in that area. Some folks don't like trimming the piston skirt to increase intake duration. Most of the time I don't do it, unless I am going to have to otherwise lower the intake floor a bunch to hit the number I want.

@farminkarman Thanks for the advice! My mistake on the intake - It was 72.5 degrees BTDC or about 145 duration. I'm thinking I'll probably shoot for somewhere between a tractor and a racecar with this one. Judging by the general disdain for this saw, I'll probably temper my expectations to building a reliable firewood saw for my dad or uncle. Probably should have researched it a bit more before buying it, but it was hard to pass up at the asking price. It was an older guy who only used it a handful of times for sturgeon fishing on lake winnebago and cut down one yard tree with it. I'll use this one to gain some experience and maybe experiment further with the next builds. There's a local lady who is giving me several lightly used 371XP and 394XP saws from her late husband. They already seem to run pretty good stock so can't wait to see what a little grinding and polishing will do for them!

 

[farminkarman]

@farminkarman Thanks for the advice! My mistake on the intake - It was 72.5 degrees BTDC or about 145 duration. I'm thinking I'll probably shoot for somewhere between a tractor and a racecar with this one. Judging by the general disdain for this saw, I'll probably temper my expectations to building a reliable firewood saw for my dad or uncle. Probably should have researched it a bit more before buying it, but it was hard to pass up at the asking price. It was an older guy who only used it a handful of times for sturgeon fishing on lake winnebago and cut down one yard tree with it. I'll use this one to gain some experience and maybe experiment further with the next builds. There's a local lady who is giving me several lightly used 371XP and 394XP saws from her late husband. They already seem to run pretty good stock so can't wait to see what a little grinding and polishing will do for them!

Don't feel bad about getting an 800. As you can see from the video Shaun Carr posted, they can turn up just fine. Its funny to see all the big expensive saws people have just for cutting a couple holes in the ice for Sturgeon spearing on Bago. Here is what I recommend you get for raising transfers: https://luckydogmfg.com/products/angled-porting-handpiece-kit I have two of them, and I run them with a Foredom knockoff from Harbor Freight.

 

[huskihl]

@huskihl Still figuring out how to use this forum. That makes sense, thanks for the advice. Do you have any recommendations on 90 degree handpieces that don't cost a fortune? Preferably one that would work with a flex shaft on a dremel.

@srcarr52 had a couple for sale that work with a Foredom type flex shaft. Don’t think they’ll work with a dremel

 

[srcarr52]

@srcarr52 had a couple for sale that work with a Foredom type flex shaft. Don’t think they’ll work with a dremel

My right angle handpiece will work with the Dremel Fortiflex motor as it's a key drive cable just like the Foredom and all the imports like the ones from Harbor Freight or Vevor. I'd recommend the Vevor SR for a cheap import motor as HF discontinued their hanging flex shaft motor.

 

[mainer_in_ak]

Don't feel bad about getting an 800.

True that! The going rate for a used 8000 or 800 is $400. I guess some of the ebay sellers didnt get the memo though.

Whats surprising about the saw, is how much they respond to basic mods. The stroke of that 81cc takes care of the rest. They run completely different than 70 cc fodder.

Even mildly modified, they hit this big flat plateau of usable torque lower in the rpm range. Then the basic mods help them carry that power further up the rpms.

Was thinking of Scott Kuntz advice on addressing choke points in a saw and why he'll leave ports alone if they're doing their job.

That restrictive flapper filter and 50 cc sized carburetor would obviously benefit from more transfer duration. But guess what happens when a cs 680 filter and an HDA 45 carb feeds factory height upper transfers?

This is what happens:
You can bury a 28"-36" bar in wood. Stop in the cut. Put over 10 lbs of leverage on the handle, touch the throttle and the darn 81 cc mundane monster comes right on step!

My next cut job will be falling 6-8 ft diameter cottonwoods in Hope, Alaska. Will be hanging a 42" bar on the cs 8000. Might go skip tooth on that one.

Then an 84" bar on my cs 1201p to mill some nice slabs:

The big monster leaning one is gonna be interesting. Gonna have to plunge-cut from both sides with a 42" bar cleaning out what could barber chair. Come out of the cut, touch that sliver ah tension wood to finish off the back cut and hope for the best i guess.

Bark has crazy shag with half a foot ridges n saddles.