Im sure there are many threads about this already but. . . . . . I have all the screws out of my crankcase and im trying to figure out how to get the case apart. I watched fred chelminski video on youtube about taking the case apart. Ive done everything he did except take the actual case apart. In the video he says he has had that specific case apart numerous times. So i guess thats why he made it look so easy. . . Any tips?
Just did it yesterday.
Put the nut back on the clutch shaft.
tap the nut using a plastic or hard wood block on the nut.
The bearing and shaft will come out the sprocket side.
Cases should come apart easy.
i actually take a socket and pound out the clutch shafte with the gear still on it so it leaves a hollow with one bearing in the other side then i carfully seperate the case by lightly tapping the crank shaft with a plastic hammer wile holding the top half of the case..... it will seperate and come apart in your hands....
hey since your case is appart..... you should stuff around the bearing bosses with jb weld and bring your case presure up to a decent amount and port match the case transfers to the jug transfers and smooth out the entire inside of the case and round out and flow the inside castings of the case transfers, it will cost you only your time and will make an unbelievable differance !!!!!!!!!!
i have a thread with step by step videos of a grubee build... grubee gt5 from the case up.. in the performance section where i show rod and piston and crank combos and some real good case work and case stuffing and csae transfer port to jug match flowing
you should check it out ... the beginning if the thread is me tryi g to figure out what i want to do with the build but by page 2 its all set to go
if i were you i would visit juice moto parts and pick up there rebuild kit it has all custom cut copper gaskets and sks case bearings and seals and you can even choose the thickness of the base gasket and the head gasket
i run a thick base gasket 1.5mm and a .45 mm or .016 head gasket
ohh and when reasembleing i must warn you that there is a sweet spot to the case ....
you will need to keep all the bolts just barley snug and give the case little taps back and forth and spinning the crank at the same time or in intervals to find the best place of alignment.... the case will wiggle a little it doesnt seem like mutch but if the crank shaft is not perfectly lined up with the bearing bosses and then tightend exactly that way it will be slightly out of alignment and cause excesse were on the bearings and drag on the crankshaft
mine turns near efffortlessly after 45min of tapping backand forth and tightening and testing and loosening and tapping and retightening and testing exe.... but it was worth it because once fully asembled the bottom end turns over the entire assembly clutch and all with only a single finger with verry little efffort.... stock it had a ton of drag and it was slightly mis aligned causeing it to turn over with a LOT more difficulty.
That sounds like a lot to decipher rogergendron1 . Can you paste the link to your videos? I wanted to say that i have a fred chelminski cylinder and head going on this case so i dont wanna mess with those two and the piston. I am new to small engines and i have a lot of learning to do. Getting the shaft out is first so i can get to the crank and have someone balance it. I also want to replace the china bearings . Guess ill have to get them out and take em to a auto store so i can compare them.