Honda Spree and Elite 50 Forums

Bear45-70 wrote:No actual kit, but you can always use a CR80 piston.


"A European catalog for Wiseco pistons (an after market supplier) listed their 1984 Honda CR80R piston as being suitable for a "Lead 80" scooter. My Aero has almost a 1 inch wide boost port; substantially more than the total .820 inch spacing on the 1984 CR80 piston. The earlier CR80 (1983 model # 493) Wiseco piston has almost an inch between the pins so its the one I eventually installed. They come in sizes from 49.5 mm to 51.5 mm and wise co pistons should be available through your local motorcycle dealer. After buying the piston I visited my local machine shop who bored the cylinder to match the piston.
The Wiseco CR80 piston is in the scooter and it works great! I had to buy a CR80 wrist pin as well because the Aero 80 wrist pin was too long and wouldn't allow me to fit the pin locating circlips into the piston. I had removed about 1/16 inch or about 2 mm off the stock head and so the compression is higher. Cylinder pressure is 160 psi. The engine really wants to rev and I've re-installed the stock weights. I haven't been driving it anywhere that I could open it up yet but 70 km/h is easily obtainable even on mild hills. Acceleration is better than before but still not as good as I'd want. The engine revs and then the variable pulley kicks up and the engine bogs down until it increases speed again. Just another reminder that increasing engine power is only one part of the equation for increased speed and acceleration."