Got my new tandem runnin yesterday. Its a $50, 60's I think Vista-Duo, 24" Whizzer wheels that have been collecting dust and 50 tooth rear sprocket. Had to make the intake do a 45, 1/2 copper 45 and 5/8 heater hose, works fine. 2 chains were kinda long so I made an additional flat idler out of some nylon that was on the shelf. It guides top and bottom of the chain. Had to extend the coaster arm by welding two flat washers to it and shaping the inside to the oblong hole with a die grinder and a file. I used a rag joint on the inside and the outside to space past the 2.125 tire(after I gave my new tire that COOL buzzsaw design with the rubbing chain). Then I clearanced the rear middle strut for the chain by removing the inside half. All seems to be fine now have ridden it about 50mls. about 5 with my wife on the rear. Seems to have plenty of power (I weigh 275 and my wife is 130ish) the Whizzer drum brake is reassuring since I'm runnin a coaster on th rear. Gonna ride it a few more miles and then disassemble it for paint as soon as it looks like no more welding is done, got to make longer chain guard and reinforce the forks. It acts like it runs cool enough but I havent really pushed too hard during break-in. This forum is great I have been watching for awhile and decided to jump in. Sorry about the cell phone quality photos.