Stihl 090 performance upgrades?

[daedna]

I was wondering if anyone kows of any good performance upgrades for a Stihl 090. So far I have ordered a racing Tillotson carb with an oversized bore and changed to a 3/8" - 11 rim sprocket. I do not want to modify the cylinder (for fear of messing it up). I was thinking about modifying the intake (carb spacer) or the muffler...or using a k&N air filter. Any suggestions??

Thanks, Dave

 

[blsnelling]

If you want any real gains, you'll have to mod the cylinder.

 

[Nitroman]

Just send it to Brad with a check and tell him you want a monster. All that needs be done.

 

[daedna]

If you want any real gains, you'll have to mod the cylinder.

Do you know where I could find detailed instructions. I looked breifly online but didn't find much.

 

[Teddy.Scout]

Brad is right!
Keep this in mind, the 090 is the BB upgrade to the 070. MAXED out.
You could start by milling the cylinder base, front side pop up, slight ignition advance, ect.
The walls in the transfers are nominal, so a side (finger port) transfer helps. BUT! be warned, it is THIN there too!
This would then entail a larger carb (well would help).

Asking for instruction or details from some is like asking a deep south boy were he makes shine! Ain't going to happen.

Doubt that helped, just what I heard. :msp_sleep:

 

[daedna]

Brad is right!
Keep this in mind, the 090 is the BB upgrade to the 070. MAXED out.
You could start by milling the cylinder base, front side pop up, slight ignition advance, ect.
The walls in the transfers are nominal, so a side (finger port) transfer helps. BUT! be warned, it is THIN there too!
This would then entail a larger carb (well would help).

Asking for instruction or details from some is like asking a deep south boy were he makes shine! Ain't going to happen.

Doubt that helped, just what I heard. :msp_sleep:

Says at the bottom you need a 090-070 Contra case...are you talking about a carrying case or a crankcase. I have an extra Contra crankcase, would need some paint tho.

Yeah, I figured some of the people might be a little tight lipped about the mods...but doesn't hurt to ask. In the first picture, you are showing a step in the piston so it can fit higher in the cylinder and then you could mill the cylinder base without crashing the piston rite? Couldn't tell what was going on in the second pic...what is finger port? Would that be a 3rd narrow transfer port? I already got the larger carb...I wonder if a bigger carb wil help even without any other mods.

 

[nate cutter]

I thought this was a spacemule joke. That will be a monster of a saw but it will still have trouble hanging with the bike saws.

 

[Teddy.Scout]

Says at the bottom you need a 090-070 Contra case...are you talking about a carrying case or a crankcase. I have an extra Contra crankcase, would need some paint tho.

Yeah, I figured some of the people might be a little tight lipped about the mods...but doesn't hurt to ask. In the first picture, you are showing a step in the piston so it can fit higher in the cylinder and then you could mill the cylinder base without crashing the piston rite? Couldn't tell what was going on in the second pic...what is finger port? Would that be a 3rd narrow transfer port? I already got the larger carb...I wonder if a bigger carb wil help even without any other mods.

I don't paint my saws, but yes I could use a case!
Funds are tight right now so I can't get on it any time soon.
Got another obligation (saw chase) going right now.

You will see some, some gains with a larger carb!
But if you are on a budget, just up the Venturi! (just learned what the name was, from reading a 3120 thread!)
Also Gary's tilliston carb rebuild thread helps with the terms!

Yes, it is a CRUDE third (and un pictured a 4th) finger port.
Don't have the good tools (foredom) grinder yet.
Just some of dads old pipe fitter files and pipe de-burrs!
It is crude, but she cooks!

I thought this was a spacemule joke. That will be a monster of a saw but it will still have trouble hanging with the bike saws.

Not bike saw!
A (Steve Jobs) garage 090 port job!




ALL YOU BUILDERS!
I don't have a degree wheel, or the know how like other!
Just a pile of trashed cylinders!
I am sure others can smoke me or easily show me up in a cut!
Just sharing!

 

[Teddy.Scout]

Keep this in mind!

Stay At Home Dad - YouTube

And ya, I get high off baby hugs!

 

[nate cutter]

:msp_thumbup: I have my 6 month old all day