Post by: Brap on May 15, 2012, 03:55:30 AM
, Muhaha Let the fun begin, i just bought a 2005 RM250 and have heard nothing but good about it, I run 87 with 32-1 Yamalube, Heres a videoWalkaround
Startup
First ride
The move from 125 to 250 was AMAZING!
I love the bike, It sits 2 feet from my bed..no lie haha {Bad part of town}
Everyone says not to run 87 but i ran 87 in my 125 and only rebuilt it once in 2 1/2 years and she ran fine, Why is this?
Post by: Stusmoke on May 15, 2012, 07:56:43 AM
Post by: Brap on May 15, 2012, 10:18:44 AM
Post by: Stusmoke on May 15, 2012, 11:26:12 AM
Post by: scotty dog on May 15, 2012, 11:40:38 AM
Post by: VintageBlueSmoke on May 15, 2012, 12:27:50 PM
Caveat: This is SIMPLE TERMS. You engineers and builders can debate me if you wish, but let's not get wrapped around the spoke for our new member.
Simply, Octane SLOWS the burn of the fuel thus cooler. 92 burns cooler than 87. Many engines, especially high compression engines, "ping" or "detonate" - some call it "dieseling". In truth, these are all the same terms but different issues. Lower octane fuels burn hotter, if the piston or squish area of the cylinder gets too hot, the fuel/air mix ignites at the wrong point in the stroke (rather than when the plug sparks). If the ignition is during the up stroke, serious damage usually occurs. Engine builders usually build an engine within very specific tolerances and with higher compression you have higher heat.
As you can see, there are many reasons you get away with 87 and that is great if you are not detonating. That means you can save a lot of money on fuel and put it to other uses. But be aware that you could also be causing damage to the engine that could be terminal. Get a good read of the piston often until you are sure of you jetting and engine temps.
Post by: cnrcpla on May 15, 2012, 12:37:26 PM
Post by: Brap on May 15, 2012, 07:40:28 PM
Post by: cnrcpla on May 15, 2012, 07:43:21 PM
Post by: Brap on May 15, 2012, 09:12:13 PM
Is it doing that Detonate thing? this is 87, i will run 93 this weekend and see the difference
Post by: Marco810 on May 16, 2012, 02:22:48 AM
Is it doing that Detonate thing? this is 87, i will run 93 this weekend and see the difference
sounds lean on the pilot, try turning your air screw in a bit
Post by: SachsGS on May 16, 2012, 04:25:42 AM
Post by: scotty dog on May 16, 2012, 12:43:50 PM
Post by: Brap on May 16, 2012, 12:48:20 PM
Pinging sounds like tin can with a coin in it when ya shake it, you will only hear it while ya ridingi'll run the rest of this 87 and see what its like, then ima fill up on 93 octane and see what she does
Post by: Recovered on May 17, 2012, 07:13:01 PM
Post by: Stusmoke on May 18, 2012, 12:49:48 AM
To find out why you can run 87 (vice other octane levels), you need to understand what octane actually does.
Caveat: This is SIMPLE TERMS. You engineers and builders can debate me if you wish, but let's not get wrapped around the spoke for our new member.
Simply, Octane SLOWS the burn of the fuel thus cooler. 92 burns cooler than 87. Many engines, especially high compression engines, "ping" or "detonate" - some call it "dieseling". In truth, these are all the same terms but different issues. Lower octane fuels burn hotter, if the piston or squish area of the cylinder gets too hot, the fuel/air mix ignites at the wrong point in the stroke (rather than when the plug sparks). If the ignition is during the up stroke, serious damage usually occurs. Engine builders usually build an engine within very specific tolerances and with higher compression you have higher heat.
As you can see, there are many reasons you get away with 87 and that is great if you are not detonating. That means you can save a lot of money on fuel and put it to other uses. But be aware that you could also be causing damage to the engine that could be terminal. Get a good read of the piston often until you are sure of you jetting and engine temps.
Thank you I never knew that. A little more knowledge never hurts