need to know mix ratio for 1991 kdx 250 been usein 40:1 wanna make sure this is right

 

I do not have a definite number for your application. Normally, on synthetic oils I would start at 40:1, run it and read the plug. I also noted that different bikes prefer different mixtures, some like it at 40:1 while others preferred 48:1. It seems like 40:1 is a good starting point for most owners manuals. My CR480 for example preferred 35-38:1

 

Thanxs i guess i nees to adjust carb looks like its runnin just a touch to rich

 

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