Stuck sprocket (better bearing installation)

[Will'smotobikes19]

So for my new build I bought Japanese bearings to replace the old ones. I got the nut off the clutch shaft but the sprocket won't budge. Stripped out a puller and the threads on the other stupid puller wouldn't grab. I tried using 2 screwdrivers and it didn't work either. I don't want to crack the crankcase. Please help this sprocket is slowing down my build. I need to get to the bearing under the sprocket to replace it. And before you say to leave the stock clutch shaft bearings I already set one of the new ones in the other side and the cover on the bearing is already melted from me heating the sprocket. I have 4 Nachi 6202s for it. Does anyone know of better quality pullers that will fit the regular 66cc engines maybe for scooters? This build is going to be a big bore 48mm x 41mm. It's almost as if the thing was welded in place it didn't even move 1mm when I was cranking on the puller. Should have just got the crankcase halves and used the better bearings right from the start, might have been cheaper.

 

[crassius]

puller is OK for getting that off - one must clean threads on both very well then GENTLY thread it in being sure it is NOT cross threaded - do not pull on it unless you have at least 4 or more threads engaged

those rear bearing never go bad as they turn very slowly - if you want, you can take clutch off other side and push shaft and bearing and sprocket out so you can get at it more easily

 

[Will'smotobikes19]

Thanks so much i popped the shaft out and put the whole thing in a vice- the sprocket came off in a few taps. Now I just have to figure out where to get the 8 bolts I need in stainless and head studs. I think i'm going to get some grade 8.8 studs the stock ones were bent and since i'm upgrading the hardware and bearings I thought why not the studs. My car is having problems right now and is in the shop so I have to budget this build. 2 of the wires (blue and white) came unnattached from the magneto so I think i'm going to try soldering them back.

 

[FurryOnTheInside]

Thanks so much i popped the shaft out and put the whole thing in a vice- the sprocket came off in a few taps. Now I just have to figure out where to get the 8 bolts I need in stainless and head studs. I think i'm going to get some grade 8.8 studs the stock ones were bent and since i'm upgrading the hardware and bearings I thought why not the studs. My car is having problems right now and is in the shop so I have to budget this build. 2 of the wires (blue and white) came unnattached from the magneto so I think i'm going to try soldering them back.

I get nearly all of my hardware through ebay, but idk what it's like over in the USA. I had to look elsewhere for some M8*0.75 extra fine thread and still couldn't get the length I needed so I'm going to be annoying my neighbours with the rotary tool again today, jeesh I hope none of them have a dentist phobia lol.

 

[Spare_Parts]

Amazon. Use all thread for the studs and cut to length. You could also order from bel-metric, great company to deal with.

 

[Rick73]

I get nearly all of my hardware through ebay, but idk what it's like over in the USA. I had to look elsewhere for some M8*0.75 extra fine thread and still couldn't get the length I needed so I'm going to be annoying my neighbours with the rotary tool again today, jeesh I hope none of them have a dentist phobia lol.

ace hardware. I get all my hardware there. threaded rods, nuts and bolts. I been sticking with stainless so they don't trust.

 

[Will'smotobikes19]

ace hardware. I get all my hardware there. threaded rods, nuts and bolts. I been sticking with stainless so they don't trust.

I went to ace too they had most of the bolts but some they didn't have in a certain length I got the 304 stainless allen heads.

 

[Rick73]

I went to ace too they had most of the bolts but some they didn't have in a certain length I got the 304 stainless allen heads.

that's what I use the Allen heads it makes it so much more convenient

 

[Will'smotobikes19]

Do you think I should use better bearings in mag wheels? how often do china bearings go bad in the mag wheels? looking to get some stainless skf or nachi bearings for the wheels that way they won't rust. On the rear wheel there is one 6000rs bearing and a 6200rs. I mean it would make it more of a quality build and the better you build these bikes the more theyr'e worth and more reliable. Looking at possibly getting the bicycle motor works red gas tank frame on ebay too.

 

[Will'smotobikes19]

I don't like amazon for hardware most of it is chinese, so you're replacing chinese with chinese. People favor cheap over good quality nowadays.