32:1 mix for our older saws

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I suppose you have never run regular gas in a hot rod with high compression and timed for performance. Put it in high gear at low speed, give it the fuel, and you will find out what spark knock is plenty fast.


There is no other purpose for octane rating other than to give the user or designer a way to anticipate pre detonation from high compression and two much advance.

Unless giving you something else to babble about incessantly is a purpose.
What your calling spark knock is detonation and has nothing to donwith the spark plug as it happens after the plug has fired. I have expiereanced it in race engines to the point the piston on the exhaust side is burnt away..
There is no such thing as pre detonation. That's a bastardized term used by people that can't wrap their minds around the fact pre ignition and detonation are two different things or they are simply ignorant.
None of this changes what I said in the post you quoted. In fact you tap danced right around your false statements. Par for the course with you.
I am well aware of what octane measures... In fact I walked past a test engine measuring MON an hour ago.
 
What your calling spark knock is detonation and has nothing to donwith the spark plug as it happens after the plug has fired. I have expiereanced it in race engines to the point the piston on the exhaust side is burnt away..
There is no such thing as pre detonation. That's a bastardized term used by people that can't wrap their minds around the fact pre ignition and detonation are two different things or they are simply ignorant.
None of this changes what I said in the post you quoted. In fact you tap danced right around your false statements. Par for the course with you.
I am well aware of what octane measures... In fact I walked past a test engine measuring MON an hour ago.

What you are calling detonation is spark knock dumb ass.

Since it has nothing to do with the plug let's do away with them, and I know. Call it a diesel.
 
I got the terminology wrong I said pre detonation I understand pre ignition and detonation are two completely different things. I've actually had detonation in a stock ms660 the combustion chamber well more so the squish band and piston had bubbles melted into it. The saw was getting very hot I knew something was wrong In the end I worked out it was the fuel it was stale and must of lost most of it's octane, fresh fuel instantly fixed the problem.
 
Not sure if it was detonation or pre ignition, but I was getting a knocking sound from a stihl strimmer engine (No shaft or anything) that I was testing out that had no load - not even it’s clutch or drum and tuned to its limit. It was going in my rc boat.

Sounded metallic, like a little ball was knocking around. Would that be detonation or pre ignition?
 
Not sure if it was detonation or pre ignition, but I was getting a knocking sound from a stihl strimmer engine (No shaft or anything) that I was testing out that had no load - not even it’s clutch or drum and tuned to its limit. It was going in my rc boat.

Sounded metallic, like a little ball was knocking around. Would that be detonation or pre ignition?
This covers it all is a good read.
http://www.masterenginetuner.com/pre-ignition---detonation.html
 
JUST PUT WHITE LIGHTNING MOON SHINE IN IT 101 PROOF THAT MO FO WILL. CUT WOOD LIKE A HOBO ON A HAM SANDWICH DON'T DRINK AND SAW LORD HOW MERCY PEOPLE 87 OCTANE CLEANS BETTER AND 93 OCTANE BURNS HOTTER JUST DONT USE ETHANOL HELL DO THE SCIENCE PUT SOME IN A GLASS JAR AND TEST BOTH I USE A COMMERCIAL ULTRASONIC CLEANER WITH MIXED FUEL TO CLEAN MY CARBURETORS ANY SAW I REBUILD HAS MORE POWER AND COMPRESSION THAN WHEN IT WAS NEW AND I REBUILD OLD STIHL SAWS 30 TO 50 YEARS OLD OVER AND OUT (CHAINSAW 101) ANY OF YOU NEED A FULL REBUILD CAN FIND ME ON EBAY STIHL CHAINSAW REPAIR CISCO THATS A BIG 10--4 RUBBER DUCK.
Maybe if the 87 had ethanol in it and the 93 was pure gas or the car had adjustable timing. Total seal has a good video on it the
 
Ps it's your saw use what you think is best just no ETHANOL and full synthetic 2 cycle oil even though newer saws are built to run ETHANOL and carb kits have the diaphragm for it I always use the non ETHANOL no matter what use safety gear and be safe sawing that's number 1 .Rubber Duck.
 
I got the terminology wrong I said pre detonation I understand pre ignition and detonation are two completely different things. I've actually had detonation in a stock ms660 the combustion chamber well more so the squish band and piston had bubbles melted into it. The saw was getting very hot I knew something was wrong In the end I worked out it was the fuel it was stale and must of lost most of it's octane, fresh fuel instantly fixed the problem.
Some of the high octane streams used to make gasoline also have low boiling points. As a result when you use old fuel its octane is lower.
 
I never knew just how close FC and FD oils are and how far behind FB relatively.

Richard Flagg has some really easy to watch YouTube content and he showed this picture of requirements. FC and FD are nearly double that of FB View attachment 1089131
Yes, which is why it's foolish to use FB in anything now days. It's really early 1980's quality level.
 
I never knew just how close FC and FD oils are and how far behind FB relatively.

Richard Flagg has some really easy to watch YouTube content and he showed this picture of requirements. FC and FD are nearly double that of FB View attachment 1089131
FC & FD are basically the same other than additional detergency & odor abatement protection within the FD specification . I have ran FC oils for years with no issues . More recently I have found a few FD oils at reasonable price points , so its a win / win !
 
FC & FD are basically the same other than additional detergency & odor abatement protection within the FD specification . I have ran FC oils for years with no issues . More recently I have found a few FD oils at reasonable price points , so its a win / win !
Alot of the FC oils required very little or no change to meet FD. Very high quality oils.
 
Alot of the FC oils required very little or no change to meet FD. Very high quality oils.
I wonder why castrol advertise their 2t activ as FD but it’s truly rated as FC. You’d think they could quite easily get that improved rating. Though I suppose they have kept that rating for their tts / power 1?

Edit: they also call it mineral, when it’s actually semi synthetic.

28240017-BAD0-445D-AC85-8C258F13A2C6.jpeg
 

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