026 Build

[bikemike]

If your comp tester has an end that takes up more volume than a plug end seated in the chamber, your comp is likely lower than what you're reading. I have that issue with my OTC tester and I believe it's a copy or the parent of the respected Snapon gauge you are using. The tip (ha ha, just the tip baby) takes up more chamber volume than a plug does.

The error is more % the smaller the chamber.

I take nearly .055 from my bands and cut it flat. Even though your band is larger because of the arc, my chamber looks smaller. I get the saws down to 104-106 ex roof depending on the jug. I bet you're lower than what it's reading on your guage, which is good.

I did an NWP jug the way you did yours and I wound up at about 210 psi.

Just porting banter. You did an excellent job there.

Just be careful in the Summer. Like Kevin said, you gotta continually be on top of tune when the compression gets near that.

This is where my 024/026 hybrid with an 044 carb wound up after a long cut in August. It was tuned to 16k going into the wood.
View attachment 66402

I like that kinda rpm

 

[Duane(Pa)]

@Fruecrue I like your muffler mod. Did you make the deflector, or is that one that can be purchased?

 

[Fruecrue]

I bought it on eBay, sold with a screen and some screws. Comes one piece, you cut to desired length and end up with 2. I brazed it on and brazed the screw hole shut.

http://m.ebay.com/itm/CUSTOM-PORT-M...%3A8b76265715b0a8618ee1b3c0fffcf087%7Ciid%3A4

 

[stihl_head1982]

BTW for anyone interested, I used an 029 fuel line I had. Measured the fuel line at .422" where it goes through the tank. Opened tank hole with 13/32" drill (.406"). Worked great, doesn't leak.

An 038 fuel line can be used on these. It has the tapered grommet. Just be mindful when you put the air filter on -- the upper section is a bit longer than the stock line, so make sure it is tucked in under the air fiter. They work just fine and are far easier to install than the stock/formed line ("J" shaped line).

 

[Fruecrue]

An 038 fuel line can be used on these. It has the tapered grommet. Just be mindful when you put the air filter on -- the upper section is a bit longer than the stock line, so make sure it is tucked in under the air fiter. They work just fine and are far easier to install than the stock/formed line ("J" shaped line).

The 029 fuel line also must be tucked under the air filter.

 

[drf256]

On that crank, I don't have a case sans flywheel to check at present.

I believe .020 off the key has been tested before to be about 4*.

 

[Fruecrue]

026 is down and out for a little while. She blowed up. My fault. Lower coil screw didn't feel right, I should have done something about it but didn't. Thought I heard something, a couple 15k piss revs later, screw went for a ride.

 

[bikemike]

026 is down and out for a little while. She blowed up. My fault. Lower coil screw didn't feel right, I should have done something about it but didn't. Thought I heard something, a couple 15k piss revs later, screw went for a ride.View attachment 67569View attachment 67570

Bummer. Loctite is a must in my opinion. Hope you get it goin soon.

 

[drf256]

Damn that's annoying.

 

[bikemike]

Damn that's annoying.

Me or the loose screw cause I think I got a loose screw lol

 

[drf256]

You don't annoy me Mike.

 

[bikemike]

You don't annoy me Mike.

That's good trying to keep the good sarcastic humor on the good site. Well you have a good night

 

[Fruecrue]

Parts are in. Used coil and flywheel, $29. I drilled and tapped the lower coil screw hole to 6mm (.236"). Will drill the coil ear to 1/4" and trim a 6mm bolt to length, a little tight but hopefully will allow proper positioning. Hope to get time in on it tomorrow.

 

[bikemike]

Parts are in. Used coil and flywheel, $29. I drilled and tapped the lower coil screw hole to 6mm (.236"). Will drill the coil ear to 1/4" and trim a 6mm bolt to length, a little tight but hopefully will allow proper positioning. Hope to get time in on it tomorrow.

Blue or red locktite lol

 

[bikemike]

I'd like to se the Lil screamer back in action. Always loved the oh26. Debating on bringing mine to a cottonwood removal job coming up but I don't want the new guys grabbing it

 

[Brush Ape]

Compression pre heats the charge. That's all it does.

You're referring to the adiabatic process. It is easier to ignite something which is already hot, but that's not all higher compression does.

A modified chamber is a smaller chamber. There's less room for the fuel mix and air to resist being blended. Evaporation increases partially from the increased heat, but also because the molecular structure of the air and fuel droplets have less real estate to expand in. More stuff smaller space intensifies the charge for lack of a scientific way to put it.

 

[Fruecrue]

026 is alive again! Drilled and tapped both coil mount holes M6x10. Drilled both coil holes 1/4" and oblonged them a bit for adjustment. Mounted new flywheel with slightly less advance just to see if it runs any different, used an HL Supply business card to gap the coil. It died with the tach in my hand, 15k. After repair, started and warmed up, 16k. Interesting. I tuned her back to 14.5.
Wondering if the difference was flywheel, coil, coil gap, ignition timing, carb? Too many variables I guess.