Bonneville America Forums Forums Technical Forums Performance Mods Swapping jugs

Does anyone know if 865 jugs and pistons will fit a 790? Got a friend that used to be a machanic for the triumph dealer before they closed said he would seal them to me don't know how much yet if I can get them for cheap I'll prolly have them borded and sleeved for 904BB that way I can just swap them with minumum down time Or I might just put the 865 stuff in it

They should. Only difference was bore size. You could go with high compression pistons from Triumph Performance USA and not bore the 865 cylinders if you want to save a step and some money.

That's true to a point Dave. Remember though I asked Carlos ahout the 865cc improvement kit for my bike but because I had done over 50,000 klm's , he believed the 904cc option was more appropriate in my case. . Something to do with the rings I believe.

True, I was just throwing it out there as an option. If they are higher mileage jugs it probably wouldn't be a bad idea to go with the 904.