1000 jugs in a 900 lower

WHAT MODIFICATIONS ARE NECESSARY TO FIT 1000 CYLINDERS INTO THE 900 LOWER? WOULD IT BE BENEFICIAL TO DO THIS AS OPPOSED TO USING A 1000 LOWER?

I know the 900 cranks are lighter. I am intrested to here some answers, because i am thinking about doing this to my 900, because i can get some 1000 jugs for cheap.

straight bolt on easy increase in displacment do it all the time, the thousand cases are a bit stronger more reinforcing ribs in the front of the cases,most guys that are racing use the 900 crank shaft because they are lighter but on the street i'd use the thousand crank because it is heavier so it dosen't vibrate as bad as the 900 crank, ether crank will work but personally i always use the 1000 for the street and i always check the crank to see if it is true then i get the pin's welded.

Well....as far as I know, the 1000 cylinder with drop right on a 900 lower. Just some food for thought though. The 1000 cases are said to be better then the 900 cases. Not sure why. I know the MK11 cases are better. The 1000 tranny is better then a Z1 tranny because the Z1 gears are squared off at the bottom of the teeth where a 1000 gears are rounded there. The squared design has a better chance of cracking at the joint where the 1000 doesn't have that spot for a crack to start. Z1 crank is better till you get to the MK11 crank because it's lighter by a bunch over a 1000 or MK11. MK11 crank is heavier but stronger because the rods are bigger and it has the 16T center pin. No difference between 900 and 1000 crank cept for the weight. In anything turning, lighter is better as long as it's strong enough to handle the load you are planning on putting on them. You can bore a 900 out to only 1015cc while a 1000 cylinder can go as big as a 1105 but better to say at 1075 for stringth issues. If you are planning to overbore, even if you have to open cases up some, it would be worth the expense but I do think the 1000 cylinder drops on. So...a 900 lower would be fine unless you plan on putting a lot of stress on it. The 900 parts will hold up to quite a bit, it's just that the 1000 lower is stronger. I know of 900 lowers running in the low 9's so it's preparation that is important if you plan on abusing it. Otherwise, slap on that 1000 cylinder and go.

very cool, maby if i can track down some thousand pistons i will do this mod over the winter.

yeah im gonna go with the 1075 with the 1000 cylinders. im gonna have to split the acse anyways...I dont trust the old cam chain then thers that undercut 2nd gear thing that needs to be fixed too.

if your going that far any way call schnitz racing and buy one of there pro-cut transmissons they are around 250 complete and no core so you get to keep your old tranny. also look ay getting a heavy duty clutch basket kit[new heavy duty rivets and springs for the backing plate.] and a needle bearing clutch pusher