We struggled to get the Whirlwind prop hub installed on the engine. We have been confused with the Whirlwind manual that Rans sent with the FWF kit. We then noticed it was for the 912 & 914. I then went on the Whirlwind site and downloaded the 915 manual.
Then we noticed that the bolts were about an inch too short with the spacer installed. I emailed Ran's tech support about this issue.