What oil is best? and what ratio?

[Keith Gandy]

Roughly how much did you have to grind off.

Just a tad where the bottom transfer cover screws will contact both sides. With the muffler off u can look from the front to both sides and see if it needs it or not

 

[Chainsaw Jim]

I didn't know we were talking about nitro methane fueled race saws?

No, but we're taking about using benol and there's no real need to mess with it unless you're dabbling with a few specific types of racing fuel.

 

[mdavlee]

Anybody ever tested the difference in heat from a stock saw to a ported one?

I think I know the outcome but never have checked.

The 7900 I checked when milling was stock. Fins were over 450 by a temp stick to check preheated pipe. Muffler was well over that. I couldn't find the 750 to see if it was that high.

 

[jmssaws]

The 7900 I checked when milling was stock. Fins were over 450 by a temp stick to check preheated pipe. Muffler was well over that. I couldn't find the 750 to see if it was that high.

I never checked the muffler but right after a decent cut i had 350 for just a second then it rapidly cooled

 

[smokey7]

With my temp gun I frequently see 600+ mufflers and have seen 400 right at the plug base on exhaust side a fair amount too. My 2stroke generator runs 675 at full load all the time on the muffler and the pipe to it gets much hotter closer to 800

 

[CR888]

It is not a surprise one bit that Jason finds degummed castor (Benol) fairly clean. Porting for better flow & removing 'dead spots' that cause eddies will vastly reduce carbon deposits.

 

[jmssaws]

It is not a surprise one bit that Jason finds degummed castor (Benol) fairly clean. Porting for better flow & removing 'dead spots' that cause eddies will vastly reduce carbon deposits.

It leaves carbon on the crown and chamber but way less than stihl oil does.
I never said it's clean but tuned right with the right ratio isn't dirty ether.

My 064 has had gallons and gallons through it at 40 and 32:1 and the piston skirt measures the same as a new piston.

I never understood why the piston crown needed to be clean anyway.

 

[bwalker]

It is not a surprise one bit that Jason finds degummed castor (Benol) fairly clean. Porting for better flow & removing 'dead spots' that cause eddies will vastly reduce carbon deposits.

But that doesn't change the fact that castor does not burn cleanly. It's inherent lack of cleanliness is related to the manner in which its decomposition path functions. In shirt the stuff forms ever more complex polymers as its exposed to heat. Contrast this with an ester that reach its thermal threshold and unzips into gases.

 

[bwalker]

It leaves carbon on the crown and chamber but way less than stihl oil does.
I never said it's clean but tuned right with the right ratio isn't dirty ether.

My 064 has had gallons and gallons through it at 40 and 32:1 and the piston skirt measures the same as a new piston.

I never understood why the piston crown needed to be clean anyway.

Piston domes shouldn't be bare metal. The problem with castor is it gums up the ring grooves which decreases cylinder life.

 

[jmssaws]

Piston domes shouldn't be bare metal. The problem with castor is it gums up the ring grooves which decreases cylinder life.

How long does it take to gum up the rings? My 064 is a 90 or so model and around the early 90's I switched to benol because that's what I ran in my motorcycle, I removed that piston in 2010 or so and it's alive and well in my 460 right now. It's worn but very little so how long does it take to ruin a saw?
Been 25 years and still ain't got it,I'll let you know when it ruins it if we're all still alive.


I'll say it once more,never said it was the cleanest just said it's not bad.
If it was bad don't you think after all this time I'd have a problem? Besides wtf do you care it ain't your saw.

 

[CR500]

What about running a little ring free with castor oils?

Just thinking out loud lol

Sent from my non internal combustion device.

 

[jmssaws]

I've had benol clabber up power valves in cr250's but they run cooler than a saw being water cooled.

It has its faults but it's supposed to have film strength like no other and for what I do with saws I don't know why I'd use anything else.
I've tried hard to seize one and haven't done it yet.

 

[Time's Standing Stihl]

Maxima 927? Best of both worlds.... castor and ester

Sent from my SM-G900R4 using Tapatalk

 

[bwalker]

How long does it take to gum up the rings? My 064 is a 90 or so model and around the early 90's I switched to benol because that's what I ran in my motorcycle, I removed that piston in 2010 or so and it's alive and well in my 460 right now. It's worn but very little so how long does it take to ruin a saw?
Been 25 years and still ain't got it,I'll let you know when it ruins it if we're all still alive.


I'll say it once more,never said it was the cleanest just said it's not bad.
If it was bad don't you think after all this time I'd have a problem? Besides wtf do you care it ain't your saw.

That would depend entirely on how hard you load the motor. The harder you load it the worse the deposits build.
Then there is also the seperation issue in cold weather and the fact it attracts water which makes rust internally and water in the fuel an issue.

 

[CR888]

Synthetics attract water........there hygroscopic too. The Shell Advance SX mineral oil I run is looking better by the minute. lol

 

[Keith Gandy]

Synthetics attract water........there hygroscopic too. The Shell Advance SX mineral oil I run is looking better by the minute. lol

What about if one uses the Stabil fogging spray? Pretty easy to use

 

[bwalker]

What about if one uses the Stabil fogging spray? Pretty easy to use

A pain in the azz to do everything you run the saw.

 

[bwalker]

Synthetics attract water........there hygroscopic too. The Shell Advance SX mineral oil I run is looking better by the minute. lol

Castor oil is very hydroscopic. Esters as used in two cycle oils have varrying degrees of attraction to H2O. They ralso breakdown in the presence of water pretty quick. The guys that think esters are the end all of two cycle lubes either are ignorant of this or overlook it.

 

[jmssaws]

I'm trying to load the crown pic but ain't having much luck.
This is the piston in my 064 hybrid,gallons and gallons through it.

 

[Keith Gandy]

A pain in the azz to do everything you run the saw.

Think it needs to be done everytime if using the saw at least weekly?