Quote:

---

80cc Cylinder. - The CR80 cylinder can work, but does require a good amount of modification. This modification is only for those mechanically inclined. You use the CR cylinder (cyl), base and head gasket, but use the MB5 head. The transfer ports on the MB5 cases are not big enough to accommodate the CR80 cyl., so you have to weld on more aluminum around the side of the cyl mounting on the cases. You would know what I mean if you lay to CR80 base gasket on the MB5 cases. Plus you must weld on aluminum behind the flywheel on the left and above the crankshaft gear on the right. This must be done because when you grind away the material to match the transfer ports of the CR80 cases the area is too thin so you must add material. The best way is to have CR80 cases next to you when you do this mod., so you can match them the best. You must use the CR80 crankshaft/rod assembly because of differences in the rod, don't worry, it is a direct swap. Then use the CR80 cyl studs. You will need to modify the MB5 head for the bigger bore, this will need to be done on a lathe so you can reshape and expand the combustion area, easily done on a lathe. Then, put your motor together and drill a new head stay hole in the frame, this is pretty easy. Use the CR80 reeds, intake and carburetor. You will need a pipe to match the power, either use the stock CR80 pipe, cut, rotate, weld and make it fit, or if you are 2-stroke tuner, make your own pipe for the power you want. Greg, the guy that did this mod said with the CR80 cyl, carb, and a custom pipe said 70 mph, and wheelies in the first 2 gears!

---