Sachs magneto woes

So my magneto wasn't the correct one for the bike I have and the key never sat in its groove. When I timed it originally it was holding. Now it's going out of time and i need a new crank or magneto

Re: Sachs magneto woes

Richard Eberline /

pics, omit the key, lap the parts. Lapping compound. Hand time.

Re: Sachs magneto woes

Ok ill get pics soon.

Re: Sachs magneto woes

You can see where the key messed up the inside of the taper a bit.

received_886936248398292.jpeg
received_208845500334786.jpeg

Re: Sachs magneto woes

lapping time, anything abrasive, hand cleaner w pumice, rubbing compound, twist twist.

Re: Sachs magneto woes

oh dude yea. very real common issue. I think maybe it's cuz of fun with coasterbrakes? but yours is 504 no? so I dunno.

Anyway happens alot.

this writeup pretty well covers what you need to do (i think, havent read it in a while)

https://www.mopedarmy.com/wiki/Lapping_tapered_crankshaft_and_flywheel_surfaces_for_good_no_slip_bond

timin is a little trickier but if you make a TDC mark for flywheel and case (i think there already is one) and make sure when you're putting it on that that still lines up, you should be fine.

Re: Sachs magneto woes

So basically from what i gather is you take the flywheel and put an abrasive compound to mate the surfaces together. This should take about 20 minutes to complete.

Re: Sachs magneto woes

♣Slew Foot♣ /

Its clockwise... Right.?

Re: Sachs magneto woes

yea exactly, valve grinding compound, spin it, clean it, line it up and pressfit it on. if theres a lip of something or galled up metal you might have to file it down 1st.

Re: Sachs magneto woes

Can't wait!

Re: Sachs magneto woes

So I bought permatex valve grinding compound. I lapped the surfaces for probably 5 minutes. The surfaces looked good and reinstalled.

Still slips....

Re: Sachs magneto woes

try again

Re: Sachs magneto woes

I've read as long as 20 minutes to get it right .

And , you have to put a bit of strength into the lapping . Pansy hands ain't gonna cut it .(edited)

Re: Sachs magneto woes

Still slipping....

Re: Sachs magneto woes

Hows it look?

20200321_170231.jpg

Re: Sachs magneto woes

♣Slew Foot♣ /

Rolling paper and redlocktite. Heat gun it will hold it.

Re: Sachs magneto woes

did u change that seal out? the taper looks sticky, when u slap on the flywheel it should be hard to pull off. sound dumb but

do you tighten the nut?

Re: Sachs magneto woes

I used an impact gun.

Locktight might work

Re: Sachs magneto woes

Blue loctite. Post back after 24 hrs

Re: Sachs magneto woes

Grinding compound and blue toctite worked!

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account