I thought of tilting the engine so the spark plug would fit.
Since for me, tilting if it is not too excessive that would require engine modifications not worth the effort to get it fit in the frame, it is just how I did it.
When I tilted the engine back, I ended up still making an adapter to get a bowl type carb to be level as well as using an elbow bend in the intake manifold so to not hit the down tube. The spark plug is the stubbiest one I could find with a heat range close to what the engine should use.
Since you have a project already started and handed over to you, whatever works is OK and go with it. The shapes in the tubes do look good!
I’m hope I have not come across as telling you how things are done, far from it, I am learning from seeing all the ways people make DIY’er motor bikes.
Initially I did this engine tilt even though I had use of a welder because I really did not want to tackle cutting and modifying frame tubes as I’m only just starting out welding.
I will someday hope to do more with welding tubes.
I welded the platform for the engine and some bosses for v-brakes that were necessary as I dispensed with the pedals that were prior coaster brakes too. I won’t be using the motor bike on the streets, just in motorcycle parks and with a mod cover for Burning Man Event to look like a fish.
Your use of a sewing machine pulley, which I have not yet seen in a picture, I am not sure you will have enough low ratio for torque from the engine. The jackshaft though can allow additional lowering of the ratio with a large pulley on it (smaller pulley on engine to larger pulley on jackshaft). It multiplies the amounts from each set of pulleys with belt to get final ratio.
I used washing machine pulley 10” diameter for my rear wheel pulley and I understand the Whizzer is 15”, but for off-roading hill climbing I will use extra lowering ratio on the jackshaft.
My requirement less than 5mph at Burning Man Event is such I intend to make a modification of my current single jackshaft to two jackshafts with three belts and 47 to 1 ratio giving 3.5 to 5.5 mph speed range. I did not want to overheat the clutch by pulsing the throttle to stay under 5mph.
Nice motor too. I used a more modern Clinton engine on a mini bike and found them quality. Nice motor bike build you have going!
MT
My thread:
Motor Bike DIY'er build to add side car maybe? (the side car was in case the weight of a art covering becomes too much for stability)
http://motorbicycling.com/showthread.php?t=29678
