how do i identify my crank?

[maxwellh]

hey guys, i got this motor and know nothing about it, like whats been done to it. im going to rebuild it and need to know what crank i have now, and how much is "too much" side to side play in the connecting rod.

the connecting rod has "R" on one side and "43G" or "436" on the other side. is this a stock crank?

i can wiggle the connecting rod side to side maybe 1mm total travel. 0 up and down travel. do i need a new one/remanufacture this one?

thanks.

 

[yb200]

should be #'s on the crank and a tiny side to side is ok....... no up and down

 

[1997blaster]

um i think side so side is ok up and down is bad correct me if im wrong tho

 

[1997blaster]

aha yb got to it lol

 

[slow rider]

just asked my brother, side to side is nothing, it is up and bad that is bad. he said one way to check if it is stock or longer is with the jug on, pust the piston to bottom dead center, measure the distance from the top of the jug to the piston, then push the piston to the top dead center and measure again. that is the stroke. he or i are not sure of the stroke on a blaster. but if they match it is stock, if it is more, the crank is stroked.

 

[maxwellh]

thanks guys, i think i might just save that money for a new crank and spend it on something else...

now what about the ?wrist pin? bearing...how tight should it be in the top of the connecting rod? is there a sleeve thats supposed to go in there? this one feels loose. dont know if its just the bearing needs to be replaced, again, i know nothing about this motor, and it came with no piston. i will be rebuilding it and replacing one case side soon. so im trying to figure out if i need a new crank now before its all apart.

is there any way to tell what crank i have by the markings on the side of the connecting rod?

thanks again guys.

 

[slow rider]

if the crank doesn't move up and down you are good, just get a wrist pin bearing and you should be good. as long as the bore is good.

 

[maxwellh]

it definitely needs to be bored, but the good thing i just measured it and im pretty sure its only 66mm, on its original bore, so once i rebuild this nasty thing it will love me long time