Derestrict?

[Hollandgriff]

I recently upgraded my 86 spree to a 75cc big bore kit. I adjusted the mixture, even added octane. It came with a bigger jet and i did that too but it still only tops out at around 30mph... What am i doing wrong?

[Wheelman-111]

Greetings:

Probably nothing. Your acceleration should have improved, but your top speed will remain limited by the low gearing necessary to get going off the line and the low top RPM of the AF05 engine. There are slightly taller gears available - from Tazland?. A pipe and porting may raise RPM a bit, but don't expect much faster than 35.

[patthesoundguy]

Wheelman speaks the hard truth of a big bore kit on a spree. You get way more torque with your added displacement but with out changing the gear ratio in the transmission you want change the top speed. The easiest way to get more top speed is to swap the belt for a 1/2" wide belt. I think the size I settled on was an ax23 that fit properly. It's tricky getting it on there without stripping the threads on the end of the crank but you will gain about 5mph. My spree with bbk, 21mm carb, pipe and belt swap did between 43 and 45 mph. If you stick to the stock carb and pipe I bet you could get maybe 38mph with the belt swap. No guarentees though

[Johnniespeed]

Both Wheelman and Pat speak the truth.
The lack of variator is the deal breaker here.
I discovered what you have found too, I love Spree's but sold them all and bought faster scooters.
I am looking to hit 85 with my latest project.