Ok I'll get a spark plug tomorrow (go with the #8 now that the summer is coming?) Do you know the size that a stock jet typically comes in? Just seen on eBay that there's a listing for 21 jets for $20. Once I get the stock jet size then I should just keep going down in size till the bike runs at its best?
Ok I'll get a spark plug tomorrow (go with the #8 now that the summer is coming?) Do you know the size that a stock jet typically comes in? Just seen on eBay that there's a listing for 21 jets for $20. Once I get the stock jet size then I should just keep going down in size till the bike runs at its best?
Hard for me to improve on StreetRiderz and Furry's advice, I agree with them totally.
Combustion chamber shape is important:
Upper right is a stock current 66cc head.
The upper left head is a modified (for slightly more squish area) stock head that works very well.
Lower center works well also, good balance of low and high rpm power.
Lower right is a low rpm type head, large squish and small chamber.
Lower left needs lots of rpm and is prone to detonation.
Upper center is an early stock head that worked well when the squishband was increased but was very soft and often warped and blew the headgasket. When the power and load were increased, it failed (as you can see by the soot patterns) by cracking in several spots.
