Wow!! Unbelievable!!! You won't believe what just happened!!!

[carasdad]

Originally Posted by cheapeto

Great post Glen!!

cheapeto you are very welcome. Ya see our junk 10 page owners manuals are written in Chinese..translated to English. Their 91 octane(by RON measurement only) equals our 87 octane. Only using American grade 91-93 octane premium gas has been argued here MANY times. But if you read the charts in the link..you will see it is not needed. The GY6 50 and 150 engines are NOT high compression racing engines(unless we build them that way)..so true American premium gas is not needed. Sure premium only costs a few cents more per tank full in our tiny 1-1 1/2 gallon tanks. But why use premium high octane to decrease the combustion rate of an already small displacement engine that needs all the help it can get to make power all ready? As for his engine damage..again that is NOT piston melting. In my shop I have seen that very same thing as shown in the pictures. To verify the cause we lined up the timing marks...pushed a piece of wire down the spark hole..and low and behold..the piston was NOT at TDC. The cam chain had jumped several teeth and the timing was WAY off. This of course caused the valve to 'kiss' the piston. The broken off metal parts bounced around in the engine as it continued its rotation while shutting down..and gave the illusion of a melted piston. Any of us that have welded or melted metal know that...when metal melts..it flows smoothly. It does NOT leave sharp edges and pitting. Like water it flows smoothly seeking its own level. Therefore what we see in the pics is mechanical damage and not heat related damage.. But then what do I know..I am a Paramedic..Cardiac Tech and Nurse..not an ASE certified mechanic... No longer in the Medical Field cause after 30 years of that I got burned out. I am also a disabled VET with 21 years service..so I am unable to work in the medical field anymore due to broken body parts and high toxin levels. Sooo...I opened my own Scooter parts/repair shop which has been a fun 9 years so far. But then when ya do something ya like doing..such as a hobby that you get paid to do...you never have to go to work right?
Glenn

[seamus26]

Originally Posted by carasdad

cheapeto you are very welcome. Ya see our junk 10 page owners manuals are written in Chinese..translated to English. Their 91 octane(by RON measurement only) equals our 87 octane. Only using American grade 91-93 octane premium gas has been argued here MANY times. But if you read the charts in the link..you will see it is not needed. The GY6 50 and 150 engines are NOT high compression racing engines(unless we build them that way)..so true American premium gas is not needed. Sure premium only costs a few cents more per tank full in our tiny 1-1 1/2 gallon tanks. But why use premium high octane to decrease the combustion rate of an already small displacement engine that needs all the help it can get to make power all ready? As for his engine damage..again that is NOT piston melting. In my shop I have seen that very same thing as shown in the pictures. To verify the cause we lined up the timing marks...pushed a piece of wire down the spark hole..and low and behold..the piston was NOT at TDC. The cam chain had jumped several teeth and the timing was WAY off. This of course caused the valve to 'kiss' the piston. The broken off metal parts bounced around in the engine as it continued its rotation while shutting down..and gave the illusion of a melted piston. Any of us that have welded or melted metal know that...when metal melts..it flows smoothly. It does NOT leave sharp edges and pitting. Like water it flows smoothly seeking its own level. Therefore what we see in the pics is mechanical damage and not heat related damage.. But then what do I know..I am a Paramedic..Cardiac Tech and Nurse..not an ASE certified mechanic... No longer in the Medical Field cause after 30 years of that I got burned out. I am also a disabled VET with 21 years service..so I am unable to work in the medical field anymore due to broken body parts and high toxin levels. Sooo...I opened my own Scooter parts/repair shop which has been a fun 9 years so far. But then when ya do something ya like doing..such as a hobby that you get paid to do...you never have to go to work right?
Glenn

Thank you for your service in many respects. Paramedics, firefighters ... you're all heroes in my book. And a scooter repair tech to boot.

Good post about octane. I've always understood octane to be resistance to ignition. My old Grand Wagoneer used to knock like crazy without premium.

I run a 150cc GY6 and I've been putting premium in it all along. In fact, if you've seen my other posts, I've kind of obsessed about it.

My question, I guess, is if higher octane means less pre-ignition, wouldn't that be a protection for your engine, especially at higher RPMs?

[carasdad]

Originally Posted by seamus26

Thank you for your service in many respects. Paramedics, firefighters ... you're all heroes in my book. And a scooter repair tech to boot.

Good post about octane. I've always understood octane to be resistance to ignition. My old Grand Wagoneer used to knock like crazy without premium.

I run a 150cc GY6 and I've been putting premium in it all along. In fact, if you've seen my other posts, I've kind of obsessed about it.

My question, I guess, is if higher octane means less pre-ignition, wouldn't that be a protection for your engine, especially at higher RPMs?

You are welcome! I would serve 21 more years if I wasn't in such bad health. Kidneys died due to chemicals we were exposed to. But of course the VA does stand behind those of us that were laden with toxins.. In fact they stand behind us... 0%..
In regards to high octane..well if ya don't have pre-ignition I wouldn't see a need for it. But if it works for ya..use it...only costs a few pennies more per tank. In my Scoot it just seems to give less power. I used to own a Turbo Charged PT Cruiser and it HAD to have high octane..otherwise it sounded like VW diesel engine going down the road.. I am not against high octane gas..I just wanted to let folks see and read that when their Asian manual says 91 octane..it is RON which equals 87 in U.S. gas. Cause many freak out or get frustrated when they can't find a gas station with 91 octane(U.S. grade gas)