Thread: any one ever????
05-28-2012, 12:13 AM #1
any one ever????
Has any one ever taken a 63m and just installed 65u cylinders while retaining the 63m head/case/crank/carbs/electrical etc.
I know it would be fastest with 65u electronics/carbs but i dont have the money to do all that right now so i was looking to just swap in the cylinders and probably go with 84.5 bore while using all 63m other parts to put it back together.
Only thing i see being an issue is heat possibly with the large bore on the 63m timing curve(which is different then the 65u obviously)
any insight would be appreciated. Have to rip the motor out to do the seals and figured while its out might as well make it a big bore and raise the comp. Anyway like said any info appreciated.
05-28-2012, 11:40 PM #2
it wont work, cylinders are different size to begin with, plus there is a whole list of other things I can go into.........but wont
05-29-2012, 10:05 AM #3
- Join Date
- Aug 2006
Bill didn't list it out so I will do My best ,, and then if I missed anything it will bother Him enough to chime in and clarify LOL
too much to change in my opinion
I have used the 63m cases for a 1200 and drilled 2 more pulse parts for the 44mm carbs and three fuel pumps ,, the 1100 crank is different at the front bearing
but works fine .
I don't think you could fuel the 1200 with the 3 38mm Mikuni's and single pump ,, and you would probably hole a few pistons trying to get it dialed in , and probably couldn't dial it in ?
I do not remember if the exhaust manifold for the two different cylinders sizes are different .
you would definitely need the proper 1200 head or have perhaps have the 1100 reworked ,, as far as the 1100 electronics I don't know how that would impact the 1200 ? but the 1200 is ridiculously thirsty so I would weigh that into anything your contemplating
05-29-2012, 10:26 AM #4
port height and timing will not work
05-29-2012, 08:08 PM #5
if im not mistaken the 1200 cylinders the same size as the "1130" big bore that people bore their 63m's out to ? i remember reading groupk doing 1130's with 38mm carbs etc ...
i just thought the gp1200 cylinders where the same with a different sleeves?
05-29-2012, 09:35 PM #6
You are correct, unfortunately it is the sleeves that all make all the difference in the world.
05-29-2012, 10:31 PM #7
oohh so just bore the stock sleeves and get the head machined to compensate for the extra bore? didnt realize the sleeves where so critical
05-30-2012, 12:01 AM #8
The stock sleeves are bigger on a 1200 cylinder vs an 1100, 84mm vs 80mm. The port timing is different as well which causes, timing issues and like stated earlier the carbs are way too small for this. you need to get 1100 sleeves it is the only way it will work
05-30-2012, 06:52 PM #9
i have 1100 sleeves, i have a full 1100 engine so i will bore those, but whats max bore that the 38's can feed since you keep saying they are too small? Thanks.
05-30-2012, 07:07 PM #10
then why are you trying to put 1200 cylinders on??? what are you trying to do? make your goal clear.
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