Big Bore

[Boggs#3]

ok I have what i believe is a 310 cylinder.The piston is a 72.95 mm. I was wondering what would be the next size up would be and where could i get it at? And also i was wondering how much can u bore a 310. Thanks

[LathersR]

Usually 4 over bores on a big bore jug. Also what kind of big bore is it?

[Boggs#3]

I dont know for shure but it is a stock jug with a big bore sleeve.

[LathersR]

You would probably have to run a wiseco piston.. Call wiseco first thing tomorrow and tell them what you have and they'll hook you up since you already have the piston size.. let them know its a resleeved stock jug

[250Rkiller]

what is the biggest bore they have for a 87 250R

[clutch22]

Originally posted by 250Rkiller
what is the biggest bore they have for a 87 250R

Sabertooth makes a 500 kit

[C-LEIGH RACING]

Originally posted by 250Rkiller
what is the biggest bore they have for a 87 250R

68mm on the stock cylinder with out useing a spacer plate.
With the spacer plate you could use the old 85/86 TRX model pistons & go up in size up to a 69.50mm. With the use of the 1986 YZ250 Yamaha piston you can go up to a 70.00mm size.

Then after that you have the big bore 295 sleeve that can be installed for even a bigger bore.
Neil

[C-LEIGH RACING]

Originally posted by Boggs#3
ok I have what i believe is a 310 cylinder.The piston is a 72.95 mm. I was wondering what would be the next size up would be and where could i get it at? And also i was wondering how much can u bore a 310. Thanks

72.95mm, thats a 73.00mm piston & next size would be a 73.50mm which is last bore be it a stock cylinder with a big bore sleeve or a Pro-x cylinder.
Neil