I'm working on a new build, using a KTMC 49cc motor. This is going into a very old Elgin 26" frame. It is a tight fit.
The motor mounts consist of two holes at the back of the aluminum case and one at the front. The holes appear to be tapered inside. I drilled them out with a 3/8" drill bit. Then, for the back mounts, I heated and bent a long 3/8" threaded rod to a 90 degree angle, then heated it again for the second bend, quickly pulled it through the hole and bent it again while it was hot. Hard to describe, but that made pretty good motor mounts.
I purchased an extra wide pedal crank on ebay from someone calling it a "Whizzer" crank, but I rather doubt it has anything to do with the original Whizzer company. This crank still doesn't fully clear the motor, but seems OK with the motor mounted high.
Getting a working muffler is a major engineering challenge. I purchased a pipe from Dax, chopped it up into sections and welded it back together in a way that would fit the bike. This is difficult and I am a lousy welder. It still has some tiny leaks, but I'm out of acetylene so it has been clamped in place. The exhaust is kind of a fiasco, but I'll make it work eventually.
The motor (engine) ships with an NGK plug, but the reach is obviously too short for the head. The plug is also too long. I got a shorty lawn mower plug that just barely fits.
The front sprocket is made for a 420 chain, but the rear sprocket is made for a 1/8" chain... So I ground down the front sprocket and put a 3/16" KMC 415 chain on there. Grinding it down took a while.
I purchased a rear rack gas tank (with rack) from Bikeberry. The tank is supposed to go beneath the rack, but it obviously won't fit my bike that way. I had to put the tank on top of the rack and then bend the rack mounting arms in several places to make it sit at a somewhat normal angle. The petcock is all the way in the back.
I am putting Sturmey Archer hubs on there with big internal brakes and using 13 gauge spokes. I managed to put a 5 speed rear hub on the bike and have cut the rear sprocket out to go around it. Looks like it will work..
I may be at this for a while.
The motor mounts consist of two holes at the back of the aluminum case and one at the front. The holes appear to be tapered inside. I drilled them out with a 3/8" drill bit. Then, for the back mounts, I heated and bent a long 3/8" threaded rod to a 90 degree angle, then heated it again for the second bend, quickly pulled it through the hole and bent it again while it was hot. Hard to describe, but that made pretty good motor mounts.
I purchased an extra wide pedal crank on ebay from someone calling it a "Whizzer" crank, but I rather doubt it has anything to do with the original Whizzer company. This crank still doesn't fully clear the motor, but seems OK with the motor mounted high.
Getting a working muffler is a major engineering challenge. I purchased a pipe from Dax, chopped it up into sections and welded it back together in a way that would fit the bike. This is difficult and I am a lousy welder. It still has some tiny leaks, but I'm out of acetylene so it has been clamped in place. The exhaust is kind of a fiasco, but I'll make it work eventually.
The motor (engine) ships with an NGK plug, but the reach is obviously too short for the head. The plug is also too long. I got a shorty lawn mower plug that just barely fits.
The front sprocket is made for a 420 chain, but the rear sprocket is made for a 1/8" chain... So I ground down the front sprocket and put a 3/16" KMC 415 chain on there. Grinding it down took a while.
I purchased a rear rack gas tank (with rack) from Bikeberry. The tank is supposed to go beneath the rack, but it obviously won't fit my bike that way. I had to put the tank on top of the rack and then bend the rack mounting arms in several places to make it sit at a somewhat normal angle. The petcock is all the way in the back.
I am putting Sturmey Archer hubs on there with big internal brakes and using 13 gauge spokes. I managed to put a 5 speed rear hub on the bike and have cut the rear sprocket out to go around it. Looks like it will work..
I may be at this for a while.