I suppose I'd compile a small list of parts compatible with our motors that arent available on any of the sites on the sides of the forum pages. These parts require little to no modifications to work.
Piston assembly
10mm Titanium wrist pin - 8.5g lighter than stock; reduces vibrations
Gilardoni silver racing wrist pin bearing - high speed, high strength bearing
46.8mm Honda Hobbit overbore piston set -
**unconfirmed** Compression height of 25.5mm and overall length of 50mm, it'll need to be trimmed 2mm at the skirt but it should work in the 80mm (dax) rod 66cc engines. Sits 0.5mm higher than stock and will boost compression significantly
40mm Honda Hobbit piston set -
**confirmed** - With a compression height of 26mm, using a short rod motor it will leave compression unchanged. Piston port
Credit to: Jaguar
Heads and Cylinders
High performance cylinders - With a 7mm spacer, and press-fit brass bushing reamed out to 12mm, it is claimed to produce immense power. Not compatible with the Titanium wrist pin. Grubee GT5 engines only (85mm conrod)
Credit to: FourEasy
Puch 70cc Hi-hi comp head - Boosts compression for more power throughout the RPM range. May need a better spark. May need to grind fins for sockets to fit.
WILL need to have mounting holes enlarged and moved further away from each other.
Puch Gilardoni 74cc head - alternate head, properly sized bore.
Credit to: Moto
Because of the extra thickness of the head and the fins, it's not only safe, but recommended to use the 12mm acorn nuts.
Crank
No link 6003 ball bearings - Our engines use 6202 bearings, I have seen many 50cc cranks that use 6203 bearings, which have the same I.D. as the 6003 bearings, but the 6003's will fit in our engines. This means there's a potential to use this type of bearing to fit a larger crank,
However because the O.D. is the same and the I.D. is bigger, the balls are physically smaller, which means it's not as strong. 1750 Lbf for the 6202's versus 1350 for the 6003's.
No Link - Grubee GT5a Super Rat Crankshaft - Utilizing the 6003 bearings, the Super Rat crank is compatible. Small gear and magneto mount should be the same size. Crank features a 40mm stroke (2mm longer than stock), and potentially better balance. May also have a longer connecting rod.
Puch 90mm conrod - Longer-than-stock rod. Needs a press to be fit (may as well balance and true while you're at it). Gives us a 12mm wrist pin for access to more pistons.
Type D motors: 80mm conrod
Grubee motors: 85mm conrod
Intake and Exhaust
Dellorto PHBG Racing carbs - At $35 with free shipping, it's a steal. 17, 19 and 21mm sizes. Properly sized for our motors, you will need a custom intake, or intake adapter shims to fit.
Credit to: Moto
YZ80 expansion pipe -
**unknown mounting modifications** I know there are a couple users on this forum using this pipe, any mounting information would be helpful. Properly sized and decades of tuning experts behind it, these pipes will likely give you a huge performance boost, if you can fit it.
Electrical
12 Volt Mini-gen Max (12v generator) - alternate coil for powering lighting systems
