I’m on my second Minarelli vertical top end. The first.. piston ejected the ring pin at 225 miles. I suspect excessive vibes probably contributed. No telling for sure. It was a cheap Aliexpress Chinese kit.
This new kit is an Athena.. kit 070100. I have put 100 miles on it.
I balanced & trued the crank this go round and it made a significant difference to the good. Vibes are way less.
The engine has a VM20 with 110/32.5 jetting… still very rich through the entire throttle range. Temperature stays between 160-185F.
The pipe is a modified to fit jog pipe..$65.
I did a few hard rips to see what’s up with it.
Whereas my first cast iron kit topped out at 48 mph this Athena kit seems to just be getting primed to go. Now that it’s fairly well broken in the power on top end is unreal for a motorized bicycle.
When it gets to about 42-45 mph the pipe is hitting and it just keeps climbing hard. The problem I’m having is it slips the clutch at about 46..47..48-49 mph. I have the clutch spring tightened all the down, I’m running 10 RDM hard pads, and 5 of the white CG upgrade pads. It’s time for a better clutch if I intend to run it up. It holds well as long as I don’t hold it open above 45 mph.
I have no doubt once the clutch issue is solved this thing will be capable of going way in to the 50mph range easily. I’m not sure I have the cajonnes to hold it pinned. This is on a 38T sprocket. I think the engine can handle a 36T with no problem.
I was looking for a little more power and Cannonball3 sort of put me on this Athena kit. It’s way more than I expected. I doubt I look for more. I can no longer say I’m under powered. The engine is a little monster now.
I’m curious to see how Cannonball3’s kit like this performs when it’s broken in.
I’ve gotten a lot of advice from Cannonball and cherry picked threads throughout this site on performance builds.
