I used a two-piece clamp-on 1"x1" shaft coupler I got from McMaster-Carr. The piece I used was 60845K37 but that was overkill and I machined quite a bit of it away an unneeded weight. You could get by with an aluminum coupler, I'm sure, like part 6115K15. Sorry about the delay.
Dan, I haven't completely decided on the 650 yet, I am still investigating. I hope to get to Mexico Mo. soon and test fly the ul powered version. What made you decide on the 650? Did you test fly one, and if so what was your impression?
The reason I am heistating is that as you know, the Ercoupe will easily cruise at 110 mph or so all day long on 4.5 to 5 gph. Most of the new kit planes don't do much better ( I have flown in several rv-12s and they might gain a couple of mph, but not 65,000 dollars worth). therefore, I am finding it difficult to justify a lot of money for a couple mile an hour difference. I am looking for an LSA eligible kit that actually hits the 138 mph sea level cruise limit.
I have found that most of the manufacturers have exaggerated their cruise speeds and I am really anxious to find out what the real world capabilities of the 650 with the Ul 350i can do. I look forward to hearing from you.
I hope that building your kit will be a rewarding and enjoyable experience.
If you are ever near the Zenith factory in good ole Mexico, MO I invite you to stop by and visit our facility at the same time. We are just minutes away from them and would enjoy having you visit with us.
Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.