Flywheel center boss swap question???

[Robi D]

Hi, I have recently aquired a 12V electronic flywheel for an Li crank with the thin taper. The boss had split at the keyway. I see new bosses can be purchased at scooter restorations for 15 pounds. I would like to get a GP Boss for this and swap them. Can this be done? Are the keyways in the same spot?
Thanks

[shocky]

yes no problem just mark were the keyway is in relation to the pickup magnets as a guide if the keyway is at the top the pickup magnets are approx in the 4 OCLOCK position ,
you might wanna use 10.9 tensile cap 6mm screws or bolts(check the heads dont hit the stator though) screwed through from the inside the nylocks on the outside, to do this the flywheel and boss will need tapping to 6mm in one go so that the threads all line up then all the swarf needs removing ive done a few but was able to get new flywheels for £32 and it didnt seem worth the hassle or expence in the end

[Robi D]

Great. I will order one up then. I have full intentions of welding a new boss in place, cause that's what i do! so I'll only have to get it in line and then check to make sure it is in the right space, bolt it up, and then weld it up.
Thanks very much.

[Diablo]

I wouldn't weld it. just bolting it wil be fine

[Robi D]

too much weight?

[oldbiker]

Great. I will order one up then. I have full intentions of welding a new boss in place, cause that's what i do! so I'll only have to get it in line and then check to make sure it is in the right space, bolt it up, and then weld it up.
Thanks very much.

realy
Are you going to use high tensile bolts (high carbon steel) and then weld them.
isn`t the boss an alloy steel aswell

If weight is a real issue go for rivets

[scoothappy]

I would email SR cause i think there is a problem using that taper. i have the simillar flywheel (af with a li taper bolted in) and SR gave a respones that I would have problems.

[Robi D]

I was going to weld the boss to the flywheel, not the bolts. I have seen this in the sticky manual.

Scoothappy have you tried yours out yet? have you had problems? I will email SR and ask.

Cheers

[Diablo]

Yeah but that was then The weding was done because it takes less time than replacing the rivits with bolts. The rivits are often too weak for tuned motors and can shear or simply come loose.
I've seen the welds crack more than a few times and think its because the boss and the fywheel are dissimilar steel as TZR steve says.
Don't bother welding just bolt it. Tested in 25hp RBS and TS1s with no problems.

[sean brady scooters]

i would also advise to bolt it rather than weld...