gas REG or HI TEST

[Dino69]

Ok for my da 100 on cans if i run hi test 93 oct will that help or hurt the motor and the same for the Da50 on a RE2

[jtec/radiowave]

Dino, on the 50 and 100 you should not really see any difference, your motors will run fine on either 87 or 93. We have always run 87 on our stuff and recently we have had a few engines specify 93 so we have switched to 93 on our 50's, 85's and 100's just out of convience and I could not tell a difference and you saw them at the snap a huckfest.

[Dino69]

Ok cool thanks Al

[Tired Old Man]

Either one works good, with one simply costing more than the other. With both DA and DL the regular garde is sufficient.

[jamesrxx951]

just remember higher octane means more resistance to burn,not more power. only way to justify higher octane is higher compression or a tuned pipe to prevent predetonation.

[scott m lyons]

Listen to the engine on up lines for detonation (pinging).If you can hear it run higher octane.Usually hotter weather I run Higher octane cooler weather lower octane.Sometimes you can't hear the pinging intill it's to late.

[jamesrxx951]

if it is pinging them richen up the high end first. pinging is lean/hot cyl temps. it can be cooled with a carb adjustment.

[scott m lyons]

	Quote: Originally Posted by jamesrxx951
	if it is pinging them richen up the high end first. pinging is lean/hot cyl temps. it can be cooled with a carb adjustment.

I've meet dino and assumed he would try that first.Yes a bad tune could make it lean thus making it hot.Pinging is from heat the fuel is preigniting and two flame fronts collide which is the ping you hear .Steping up the octane stops the preignition. Most people tune for rpm and run it I always like to pull a plug or two in the middle of the day just to check color.

[branwell]

My DA on pipes sounds like it has rocks in the exhaust on 87.
92 fixes it.

[Dino69]

well my da50 on a re2 has that rock sound now, i have played with needle settings and its always there. It not like i can shim the heads on these motor to help it stop pinging. My da 100 on rear dump cans gets that pinging sound in the mid to high side of the throttle at times, i have the needles opened up allot in my opinion 1.75 on the high and about the same on the mid on the 100 well ill just give it a try and see what happens the worst thing is i have to dump 5 gals of weed killer some where

[airborneSGT]

STIHL and other manufacturers of power equipment specifically warn against the lower test gas. They will not do warantee work on power equipment run on lower test gas as many blends contain ethanol. Ethanol has a strong afinity to water and it causes all sorts of damage to small engines (mainly priming bulbs, carbs, fuel lines).

http://www.msnbc.msn.com/id/25936782/

At the very least make sure there is no Ethanol in the lower grade fuel. There are tests kits to verify this. If I spend close to $1k or more on a toy airplane engine you better believe I will spend a couple extra bucks to make sure the fuel I put in it will not damage it in the long run.

[RTK]

	Quote: Originally Posted by branwell
	My DA on pipes sounds like it has rocks in the exhaust on 87. 92 fixes it.

Yep, that bag of rocks rattling is a sure sign. In hot weather (especially if piped) I bump up a grade or two.

[jamesrxx951]

	Quote: Originally Posted by branwell
	My DA on pipes sounds like it has rocks in the exhaust on 87. 92 fixes it.

if you run tuned pipes or higher compression you need higher octane gas. tuned pipes affectivly raises the compression-kinda like forced induction.

[IBTRIN]

subscribed

[Tired Old Man]

There is no mid needle on a DA 100 carb. I'm holding one in my hands right now and it's still a 2 needle carb with the model number scratched off. If someone is running 1-3/4 open on both needles they're likely just hearing a very wet running mix.