Been thinking (after I bust an engine I sometimes will reflect on it) about jetting.
So, I'm adding 15 hp to 170 hp (+/-) for about 9% increase. I was successfully running 135 mains at 170 hp and was slightly on the rich side. All other components being unchanged (clip position, air box, ect.) what would I need to increase the main jetting to?
If maximum fuel flow is calculated for the 135's at 1cc per jet size per minute (Mikuni specs), my maximum flow would be 135cc x 4 carbs x 60 minutes / 3785.4cc/gal = 8.56 gal/hour.
Is an increase in HP directly in proportion to a required increase in fuel flow? ie: 135 + (135 x 9%) = 147 or 9.33 gal/hour??? In past experience, I have found 142.5 to be way too rich for the same engine in a 150 hp version.
So, I'm adding 15 hp to 170 hp (+/-) for about 9% increase. I was successfully running 135 mains at 170 hp and was slightly on the rich side. All other components being unchanged (clip position, air box, ect.) what would I need to increase the main jetting to?
If maximum fuel flow is calculated for the 135's at 1cc per jet size per minute (Mikuni specs), my maximum flow would be 135cc x 4 carbs x 60 minutes / 3785.4cc/gal = 8.56 gal/hour.
Is an increase in HP directly in proportion to a required increase in fuel flow? ie: 135 + (135 x 9%) = 147 or 9.33 gal/hour??? In past experience, I have found 142.5 to be way too rich for the same engine in a 150 hp version.