50cc and 20" 3/8 bars

[Red97]

I didn't take any. I will take some on my next build. All the saws I had here are waiting on parts. So this was a last minute ahh let's give it a go. Lmao. Yes there limited and a small venturing carb like the echo. The transfers ports are freaking tiny. Not much room to bump the comp without free porting. Muffler mod is a pain in the azzz. Thought about putting a 5100 coil on it to grab the 14500 but this one limits at 13500 and pretty easy to tune so far so I havnt ordered one yet. That's the cliff note version. Lol.

Well the number look solid based on the limiters you described.

Without actually seeing the transfers, I would possibly take them up to 118 for a little more time, and the ex to 104 with intake and ex at 63-5%. But then you might have to swap out the carb and coil to take full advantage. I like my little saws to spin. And .325 is very forgiving with my heavy handed cutting style.

 

[Miller Mod Saws]

Well the number look solid based on the limiters you described.

Without actually seeing the transfers, I would possibly take them up to 118 for a little more time, and the ex to 104 with intake and ex at 63-5%. But then you might have to swap out the carb and coil to take full advantage. I like my little saws to spin. And .325 is very forgiving with my heavy handed cutting style.

Actually I'll start the other way. I'll stay at 105. Give it more blowdown 127/ and put the intake at 75. Give me working room.

 

[Red97]

Actually I'll start the other way. I'll stay at 105. Give it more blowdown 127/ and put the intake at 75. Give me working room.

Sounds fair, what do you think you will gain increasing the blowdown/leaving the transfers lower? More torque?

The way I see it the lower transfers will keep the case compression higher, thus once the transfer open it will flow at a greater pressure, but not necessarily more volume.
Seems that may make the saw "peaky"

I May be wrong though.
Honestly don't know that is why I'm asking.

 

[huskihl]

Sounds fair, what do you think you will gain increasing the blowdown/leaving the transfers lower? More torque?

The way I see it the lower transfers will keep the case compression higher, thus once the transfer open it will flow at a greater pressure, but not necessarily more volume.
Seems that may make the saw "peaky"

I May be wrong though.
Honestly don't know that is why I'm asking.

It's a dolmar thing. Voodoo

 

[Red97]

It's a dolmar thing. Voodoo

True...

 

[bikemike]

So this one shouldn't have an issue pulling 60DL of 3/8 then?

After seeing this pic my echo will definitely need some more breathing room

 

[Miller Mod Saws]

Sounds fair, what do you think you will gain increasing the blowdown/leaving the transfers lower? More torque?

The way I see it the lower transfers will keep the case compression higher, thus once the transfer open it will flow at a greater pressure, but not necessarily more volume.
Seems that may make the saw "peaky"

I May be wrong though.
Honestly don't know that is why I'm asking.

The 5105 has a tight cranckcase just like the 7910 thus I will hive it more blowdown. And it's way easier to give it less than more after ya have ground.

Taking the intake back up to 75 will give me more case compression. We will see.

 

[mdavlee]

The 5105 has a tight cranckcase just like the 7910 thus I will hive it more blowdown. And it's way easier to give it less than more after ya have ground.

Taking the intake back up to 75 will give me more case compression. We will see.

108/122

 

[Miller Mod Saws]

108/122

Are you hinting me where to go buddy? If you are thank you! What intake?

 

[mdavlee]

Are you hinting me where to go buddy? If you are thank you! What intake?

I would try that before raising the exhaust on the next one. These little saws don't respond like the bigger ones. 76-78

 

[Stihl working Hard]

Very nice saw there

 

[Mastermind]

108 Seems way too low...but he might be spot on. I leave the 500p at 108.

 

[mdavlee]

108 Seems way too low...but he might be spot on. I leave the 500p at 108.

It may be but it's easy to try it and raise it to 105 or higher. I used to have numbers for those but it was on my pad that got soaked. I'm trying to remember what they were.

 

[Miller Mod Saws]

Love a numbers discussion first thing in the morning!

 

[Red97]

The 5105 has a tight cranckcase just like the 7910 thus I will hive it more blowdown. And it's way easier to give it less than more after ya have ground.

Taking the intake back up to 75 will give me more case compression. We will see.

108 125 75 ought to be pretty stout...

Like you said, easy to go higher.

Enjoying these threads a lot

Keep up the good work, and Thank you for sharing.

 

[lwhaples]

Good learning thread. Always enjoy the numbers.

 

[Mastermind]

I've been porting saw after saw for several years now. But......I think I've learned more in the last few months than I have in a long time.

 

[Miller Mod Saws]

I've been porting saw after saw for several years now. But......I think I've learned more in the last few months than I have in a long time.

So old dogs can learn new tricks!

Hi Randy!

 

[CR500]

These 50cc saws have sparked interest.

What saw would you recommend for 16-18'' bar duties???

Stuck between all 3 as of now. Kind of digging the tiny dolmar lol

 

[Red97]

These 50cc saws have sparked interest.

What saw would you recommend for 16-18'' bar duties???

Stuck between all 3 as of now. Kind of digging the tiny dolmar lol

Probably not one of the 3 you are thinking, but this dolmar is pretty interesting...