was thinking about buying a long stroke crank for gilera runner 125 but was not sure how much setting up there is for one of these cranks or can you just fit the spacer and it will be ok and that makes it a 183 can any one help cheers
i also would like to know as my friend is realy set on doing this but is not to sure what is diffrent from a 125 crank ect.?
well, the conrod and stroke are longer so the top and bottom of the port's are in the wrong place.. also the degree at wich they open and close is wrong. without correction there a bit lazy.. once you correct the ports there MONSTERS altho ring life is reduced from the higher piston speed.
crank so i could just fit the crank with the spacer but wouldnt be that good. to correct it would the bore need porting cheers
yep.. needs correction to all the hights. can run without but why use a long stroke crank and stock timings? tbh i sudgest people only get a long stroke if your porting the barrel anyway thus killing 2 birds with one stone.
crank does the bore need alot of porting to work with the long stroke crank and can you minor port a bore to work with the crank and if so how much do you charge cheers
simple bottom correction is 50.. with hight raise and some reprofiling of the exhaust port/shape i usually charge 150 and this never disapoints. its a pain to do tho as you have to mark up bdc on the barrel wall once youve set squish...
nah, just build it.. then take the head off. spin the piston to bdc then run a pen round the top of the piston.. theres fractions of a mm in it really and it can be done without you doing this but its guesswork. from that i can grind the bottoms and tops to within 0.1mm tollarance to your exact stroke/squish setting
crank ok cheers minor i have not yet built the engine yet but am now defo thinking about the long stroke crank an what one do you think is best the bgm 55 or the pm tuning long stroke cheers you mite be seeing my bore soon if i get the cash
