Sachs 505/1A Rebuild - Timing

Brian Smith /
bsmith
Feb 16, 2020 10:24PM

Rebuilding my '77 Commuter Sachs 505/1A, going well so far just two quick questions if anyone can ease my mind...

1) Didn't mess with the magneto or flywheel other than removing them in tact to split the case, does that mean the timing will be roughly unaffected upon reinstall? It spins OK without any rubbing or noises. Will likely check the timing anyway to be sure, but just curious if I could technically try starting it up without fear of damage.

2) Is it normal for the mainshaft and pedal gearing to be a little slow turning at first, keeping in mind I've yet to put fluid back in the case? Confident I put everything back together correctly, but there's a little resistance during hand turning (no metal noises or grinding). Makes me wonder if I torqued down the case too hard or something, I had the tightening sequence and torque specs just didn't have a wrench that went that low so I guesstimated.

Thanks for the help, this site has been huge for me.

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Re: Sachs 505/1A Rebuild - Timing

pat splat /
ggspeed
Feb 17, 2020 12:26PM

sachs r timed really advanced stock.

as far as a little stiffness, hopefully that'll dissappear and not affect power.

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Re: Sachs 505/1A Rebuild - Timing

Born to be WillD /
willd
Feb 18, 2020 04:49PM

pedals are definetely slow til it gets lubed. it's actively spinning the clutch and there's some inherent friction there even when not engaged.

the messup most folks make (myself included) is forgetting the get the pedal engagement loop tab in between the slots in the case half. this makes the backpedal not engage the brake, but worse can make the pedals lock engaged with the motor and start whipping around while riding. wild! if tha's good, very little to worry bout.

I'd retime it to around 17degrees btdc, as pat mentions it's pretty advanced stock

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Re: Sachs 505/1A Rebuild - Timing

Brian Smith /
bsmith
Mar 14, 2020 05:11PM

Update - got the motor back on the bike today and started it up, running but definitely sluggish getting up to speed. Pedal action did loosen up a bit with oil but still tight. Both those issues are compared to what it was before I took the bike apart. I also timed it to 17 degrees btdc and confirmed the clutch setup. Think I need to just run it a while to hopefully work out the kinks or any ideas what to check next? Thanks for the input.

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Re: Sachs 505/1A Rebuild - Timing

pat splat /
ggspeed
Mar 14, 2020 06:00PM

did u rebuild? what happens when u blip the choke? how does it sound?

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