2017 Apollo 250 Build - Have questions

Douglass · 02-14-2018, 01:08 AM

Quote:

As far as jetting recommendations, what I would recommend is just a generic, and likely too rich setup to start with, but too rich is better than too lean. You will want to have a few sizes of each jet to really dial it in.
My recommendations still stand with a 27.5 pilot and a 115 or 117.5 main jet with the OHC motors. If you have an OHV motor like me I can give you far more precise jetting suggestions, because I have hands on experience with it, and I don't have an idea of how different, if any, the OHC engines are in terms of fueling.

I would say to buy a 25, 27.5, and 30 pilot. And have a 110, 115, and 120 mains, at minimum. If you feel like it, grab a 112.5 and 117.5 as well. With my bike, the 115 was a touch too lean, and the 120 was too rich, the 117.5 worked out the best for me - being just ever so slightly on the rich side, which is what I prefer with aircooled engines.

Dan I bought the Mikuni Carb after talking with Sean. His bike ran great, and his idle/acceloration improved a lot. He used a 27.5 pilot, and a 115 main, and did not make any needle adjustments. Bike ran/started perfect. He is at about 800ft, and it was about 45-60 degrees.

I am at about 60-200 ft where I'll be riding the bike, and the temp will be about 50-100 degrees (right now were around 50-60 deg) (Summer will be around 90-105). should I start with the same 30/115, or should I start with a 30/117.5? Currently I have it jetted at 30/117.5, but I have 27.5, 25, 112.5, 115, & 120 jets if needed. I am planning on installing it this weekend.

Megadan · 02-14-2018, 12:28 PM

Quote:

Originally Posted by Douglass

Dan I bought the Mikuni Carb after talking with Sean. His bike ran great, and his idle/acceloration improved a lot. He used a 30 pilot, and a 115 main, and did not make any needle adjustments. Bike ran/started perfect. He is at about 800ft, and it was about 45-60 degrees.

I am at about 60-200 ft where I'll be riding the bike, and the temp will be about 50-100 degrees (right now were around 50-60 deg) (Summer will be around 90-105). should I start with the same 30/115, or should I start with a 30/117.5? Currently I have it jetted at 30/117.5, but I have 27.5, 25, 112.5, 115, & 120 jets if needed. I am planning on installing it this weekend.

I would say to start with the 30/117.5, and then dial in the jet sizes. Dial in the pilot with idle mixture tuning and the main jet with a plug chop.