Fixing first moped! Carb and front brake questions.

Kaylee Buchholz /

Hi Y'all I just bought my first moped (79 Colombia with a Sachs 505 1A) and I'm trying to get it up and running! The engine runs and idles fine the problem is that when you open the throttle you get little to no power it even struggles to push you on a flat surface. I talked with some people and they suggested starting with the Carburetor (Bing 85/12/101). I pulled it apart and started cleaning it, but the float pin is stuck and I think the choke slide is missing? I'm thinking about just buying a new one and just maintaining it rather than trying to fix it as my friend said the Bing's were not the most reliable in the first place. Do you guys have any recommendations on what to get and will fit on my bike? If it makes a difference I'm thinking about eventually getting a piston kit for it once I get more comfortable working on the engine. the other issue I have been having is with the front brake assembly. When you apply pressure to the brakes the whole thing rotates with the wheel and locks in a position where the arm can't move. I'm having trouble finding pictures of what it is supposed to look like and have yet to open it up. Is it supposed to attach to the forks in some capacity to stop it from spinning or is it likely an internal mechanism is busted? Thanks in advance! ~Kaylee

Re: Fixing first moped! Carb and front brake questions.

Wish you had posted before taking the carb apart....it is very possible the exhaust is stopped up rather than carb problem..there is a slot on the front fork and brake assembly to keep it from spinning..if you look close you should be able to see it...post a pic of what you have so we can determine what your choke is missing..

Re: Fixing first moped! Carb and front brake questions.

Kaylee Buchholz /

Well that's unfortunate I'm gonna be headed over to look at my moped soon so i can have you pictures in an hour or so. How can I check if the exhaust is plugged?

Re: Fixing first moped! Carb and front brake questions.

Kaylee Buchholz /

Here is the picture of the carburetor and all the pieces it had!

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Re: Fixing first moped! Carb and front brake questions.

Having trouble making out for sure but it looks like the shock posts are turned tge wrong way..maybe somebody with better vision and screen can tell for sure..that carb does look like it needed cleaning....take the exaust lose at the cylinder and start it to see how it does... you can clean it iut most times with oven cleaner and water if it is plugged.. (edited)

Re: Fixing first moped! Carb and front brake questions.

The fork legs are either turned around or are on the wrong sides, can't tell which from your photo.

The fender tabs with the two holes face towards the rear of the bike, and the pin (the welded little pipe on one side) needs to be on the inside of the right leg.

The big bracket on the hub slides over the fork pin, and holds it in place.

Re: Fixing first moped! Carb and front brake questions.

Yeah. That right fork leg needs turned 180* (clockwise” so the post sticks inward and goes into the matching hole on the brake plate.

No power can be clogged exhaust. Make sure the carb is sealed good on the intake and a good gasket between intake and cylinder. Because a leak there will suck air and make you lean.

Re: Fixing first moped! Carb and front brake questions.

Kaylee Buchholz /

Ok I thought it might be backwards! How would I go about fixing that? Is it just a matter of muscle power or is there a fitting somewhere to take loose?

Re: Fixing first moped! Carb and front brake questions.

Beach Club Nick /

Unscrew the shock after removing the wheel. Replace the correct way and screw back in (edited)

Re: Fixing first moped! Carb and front brake questions.

Kaylee Buchholz /

Guess who has brakes! This girl! About to pull the exhaust will post pictures soon! I finished disassembling the carb (was able to get that pesky float pin out) it’s cleaned and waiting to be reassembled as soon as my dad wakes up and cuts me a new gasket (my hands are too shakey) Thank y’all again for all your help!

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Re: Fixing first moped! Carb and front brake questions.

Kaylee Buchholz /

Alrighty got the exhaust pulled gonna run to the store for some oven cleaner I know the pics aren’t the best but how dirty does it look and any recommended cleaning tips?

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Re: Fixing first moped! Carb and front brake questions.

That carb looked pretty gunky so def clean out all the passageways and brass jet apertures. Pipe does not look that bad to me. Are you still running the stock air box? After cleaning the pipe and reinstalling, next step would be to check for air leaks because lack of power under load usually points to a lean air/fuel mixture.

Also, if you haven't read it yet this is a great place to start: https://www.mopedarmy.com/wiki/Fred%27s_Guide

Re: Fixing first moped! Carb and front brake questions.

Kaylee Buchholz /

Stock air box wasn’t on it when I bought it I got this little silver guy instead! Fred’s guide is awesome I used it when making sure I had spark! And when I was playing around with the fuel screw before deciding to take off the carburetor!

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Re: Fixing first moped! Carb and front brake questions.

That looks like a high flow air filter. They allow more air to be sucked in to mix with the fuel. This will lean out the fuel mix, and is likely your issue. If it hasn’t been done already, you probably need to upjet, meaning put a larger size jet in the carburetor to let more fuel in to mix with your extra air.

Re: Fixing first moped! Carb and front brake questions.

Kaylee Buchholz /

I followed your guys advice and I got her running great! Only problem is she only runs great without the air filter attached my working hypothesis is that maybe the engine doesn’t have the power to pull the air though the filter I think it’s for a motorcycle? Is there a new type of filter you would recommend it would be great if it’s something that I can acquire locally

Re: Fixing first moped! Carb and front brake questions.

If you're keeping it all stock it will run best with the stock air box and filter. Maybe post on the Buy/Sell forum that you're looking for one, they will likely be cheap if someone has one.

Otherwise you need to tune your carb to the type of air filter (or lack of air filter) you plan to run. Did you take off the air filter and that long tube that attached it or just the filter?

Re: Fixing first moped! Carb and front brake questions.

filter is adding just enough restriction that it's making it run rich. or you enlargened the main by "thoroughly" cleaning it. I put a piece of panty hose over my sachs box w just a rubber band and adusted the jet size.

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