Thursday, June 2, 2011
So, it was 57º F this morning and I decided to test out my theory that the carburetor is jetted too lean. I did this by applying a small amount of choke even after the engine had warmed up. It certainly ran better than it did without any choke at all. This leads me to believe that the 125cc engine is too small of a mass to keep the necessary heat for the engine to perform optimally. It also explains why it ran so poorly in much colder conditions. So, I ordered a #102 main jet from Carb Parts Warehouse (along with a pilot jet upgrade for the TransAlp). I already own a #105 main jet since it came with the carburetor off of the ACT200X. So, I can step up one or two main jet sizes in an effort to eliminate the hesitation I've experienced. What I find slightly odd is the fact that the same carburetor is used on various other Hondas, with different engine displacements, and the main and pilot jets are same. So, I guess it's not surprising that the jets may not quite right, in the case of the NX.