Is this moped worth restoring?

Nicholas Smith /

Hey all. I don't know much about mopeds but I've been a long time member of the motorized bicycle community. I wanted to buy an old non runner moped to fix it up but this one might be beyond the point of basic diagnosis and repair. I don't know much about it but it's a Sachs Balboa I think. The headset says "1977" on it, if that means the year of manufacture. The engine is a Sachs 505/1a. The motor is in pretty rough condition... it would probably need to be rebuilt and a new topend. It does turn over, but no spark. The electrical components are many decades old and probably all need to be replaced. The frame and wheels are actually in decent condition, just years of dirt and rust. The tank is also completely filled with rust and gunk. I really like the look of the bike and would love to restore it but I don't know if it's worth the hassle. Could this be a project bike or am I biting off more than I can chew?

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Re: Is this moped worth restoring?

Restoration shouldn't be that hard, but you should do it because you want to, it won't make you any profits.

Re: Is this moped worth restoring?

Sure, do it.

If you want a better power plant change it to an e50 then you can run many different kits with much more power handling.

Re: Is this moped worth restoring?

Nicholas Smith /

Thanks. I'm trying to find out what would need replacing. The points do open and close but there seems to be no change in continuity. I understand the basics of rebuilding the motor but I'm a little lost on the electrical side

Re: Is this moped worth restoring?

The points closing should ground out the coil.

Open should be the coil resistance

Closed should be zero.

When they open that when the spark happens. If it’s not grounding the coil out, sand or file the points until they do

Re: Is this moped worth restoring?

Nicholas Smith /

Thanks. I'll try that

Re: Is this moped worth restoring?

Nicholas Smith /

I sanded the points and gapped them, and checked the resistance. It's zero when closed and 1.2 ish ohms at TDC. I spun the flywheel with a drill and an arc actually jumped the gaps between the points. Is this good or bad? What should I do from here to try to get spark at the plug?

Re: Is this moped worth restoring?

> Nicholas Smith Wrote:

> -------------------------------------------------------

> I sanded the points and gapped them, and checked the resistance. It's

> zero when closed and 1.2 ish ohms at TDC. I spun the flywheel with a

> drill and an arc actually jumped the gaps between the points. Is this

> good or bad? What should I do from here to try to get spark at the plug?

Assuming you have the coil and spark plug connected, you should not see arcing across the points.

The most usual cause is a bad condenser. Replacements are cheap and readily available.

Re: Is this moped worth restoring?

Read Fred's Guide in the wiki and everything you can here about Sachs 505's. You should be able to clean that up and with a good exhaust pipe get to 30 mph or so. Worst case rebuild with new bearings and seals. See how she spins and what the piston and bore look like first. You can always add a cylinder kit later. Make it go, then make it go faster.

Re: Is this moped worth restoring?

Nicholas Smith /

I HAVE SPARK!! The plug is sparking. I think the points were arcing because I messed up the wiring to the coil. This is amazing, I might be able to even make it run. I opened up the cylinder and piston, and while it looks terrible from the outside on the inside is only some light scoring. I think it might have enough compression to run

Re: Is this moped worth restoring?

Nicholas Smith /

Oh, also does anybody know which way the open end of the piston rings should be pointing? I faced them towards the intake because my logic is that the open end of the rings would never get that low so they can't get snagged in a port. Or are the open ends supposed to point towards the exhaust? Does the arrow on the piston have anything to do with this

Re: Is this moped worth restoring?

The arrow on the piston should be pointing towards your exhaust. The rings should only be able to go on 1 way, there are small pins in the piston to keep them aligned.

Re: Is this moped worth restoring?

This is cool! You have spark, so now you need fuel flow and air. You are 1/3 of the way there.

Re: Is this moped worth restoring?

Nicholas Smith /

The motor turns over but I don't know if the topend is any good. I'd really not liked to have to replace it. When I first got the bike the motor actually blew my thumb off when I turned it over. Is this cylinder still good? It has some minor scoring near the bottom. The piston looks worse though, it has alot of scoring. Is it recommended to hone the cylinder and get a new piston and rings? The cylinder is the stock 505/1a

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Re: Is this moped worth restoring?

The piston looks bad but is probably fine.

Usually I would take the rings off and sand a bit of the piston where the scoring is to get off any high spots, then wash well with dish soap then put back on lubed rings and you’re ready to go. Just be careful taking off the rings. You pry em open just enough to get off the top of the piston (edited)

Re: Is this moped worth restoring?

Jesse Nordlander /

Work those rings off nicely, clean the lands up to allow rings free movement. Lightly sand rough high spots on skirt. Leave cylinder alone, sling it together and roll out.

I polished this turd and it runs.

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Re: Is this moped worth restoring?

yea it's not great but not "won't run" bad. also any cylinder scoring below the exhaust port doesnt matter really at all, that parts' never sealing anything, rings dont go down there, doesnt affect it running.

Cool bike, I really love sachs, but I also love a challenge, and they can be that. But they can also be really great. Enjoy!

Re: Is this moped worth restoring?

Scottie Hartpence /

i think it is a great idea to redo this restore

go to treatland and sign up for questions

they are really smart and have everything you need from tires to motors(somtimes)

and Myrons mopeds is a good source as well

you can even get new rims /wheels sometimes and they have sales 15% off

Scottie

i have General mopeds and they helped alot

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