32 to 1 ratio MX2T

 First of all, this is not about which oil is better. This is about which ratio I feel provides adequate lubrication for my riding style - MX.

In fact, the Mobile MX2T piston looked the best at 32:1, but I do not care for MX2T (won't go into details).

At 40: 1, the Klotz R50 looked good, no scratches, but things were getting a bit too shiny on the intake side.

Amsoil 50: 1.....well...you can see for yourself. Heavy vertical scratches appear on the intake side.  This is not dirt or ingested water related.  This is solely due to a lack of lubrication.  All the top ends were serviced at 45 to 50 hours on a 2003 KX250, B-rider, MX only. I am currently testing the Amsoil for a second time at 32 to 1. Just to prove my point! I do not believe in 50:1 ratios (for MX anyway) - Check back to see how the Amsoil looks at 32:1.
 

40 to 1 ratio Klotz R-50

 If you look at the scratches, they are forming inline below the piston ring locating pins. The KX cylinder has an aggressive intake port. I believe that the center of the piston swells into the intake window of the cylinder where there is no support.

If you look at the pistons below the locating pins, they ride on a thin wall and this is where all of the support is centered. You need all of the lubrication that you can get.

The KX250 cylinder, I believe, is excellent at testing oil ratios. Not all porting layouts will show such results.

Like mentioned earlier, I am running the Amsoil again, but at 32:1, in order to prove that 50:1 does not provide enough lubrication for anything more than trail riding which is the suggested ratio from the oil manufacturer. I do like the Amsoil, but I do not see where they get off suggesting to run 50:1.  They fail to take into account different rpms being sustained (80cc-500cc) and different riding styles.

50 to 1 ratio Amsoil

  

I did pull my pipe after I burned a gallon at 32:1 and the power valves are VERY VERY clean, the exhaust port is as clean as a whistle, and just by looking at the skirt of the piston on the exhaust side, 32:1 is the ticket.

Anytime you perform jetting, stay consistent with your brand of oil, type of fuel, and oil-fuel ratio. 

 

Additional Tip -

100 LL AV Gas or a good race gas will result in more consistent jetting.

 

 

Note: The black line you see under the piston window is just magic marker. Also, jetting changes were made to accommodate different ratios and oils

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