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Discussion Starter #1 (Edited)
For my first post I'll try to be as detailed as possible.

I recently purchased a 1983 Suzuki FA50 moped with 1500 miles on it. It has been sitting in the shed for 3 years in New England weather. The transmission needed reassembly, a new spark plug, rubber lines replaced, tires and a good cleaning. I have complete the transmission; sealed, filled and functional. The previous owner never stored the bike properly thus most of the oil and gas leaked into the block and muffler. I plan to drain and clean out everything without taking apart too much if I can. I have removed the cylinder head and wall allowing the piston to hang and crankshaft chamber to drain.

I am using this manual as a guide. 1980 Suzuki FA50 Service Manual

Now for the questions.

1.) What should I use to clean these components and how much oil should be in the crankshaft chamber before I start the bike for the first time in 3 years?

2.) I am also replacing the piston rings. How should I fit the new ones on, and slide it back into the cylinder wall? The cylinder wall is slopped at the end, so I assume I don't need a ring clamp. The maintenance guide does not call for a ring clamp either.

3.) How do I clean the head of the piston? Carburetor cleaner doesn't do much and I don't want to remove the piston from the block. Is it okay to leave it alone like that?

4.) How much of the carburetor should I take apart for cleaning and adjustment? Is it finicky, requiring specialized tools like those used on larger bikes or cars?

5.) Should I open and work on the flywheel magneto? The screws that hold the cover plate on are impossible to loosen by hand. I might need to use an impact hammer, but I don't want to spend $80 for one.


If I can resolve these issues I'm pretty confident I can get the bike running again. Let me know if there are any possible unforeseeable issues with this moped. Any tips will help as well.

Thank you in advance.
 

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I'll answer your questions in order.

1: I am not sure which components you refer to but in general small delicate items need gentle scrubbing with a de-greaser/cleaning fluid. A small paint brush or tooth brush is usful to get into hard to get to places. Bigger bits such as the barrel can be wire brushed with de-greaser... externally only... to remove rust or build up of gunk. As to how much oil should be in there is there a dipstick somewhere????...not too sure what you mean here. Oil level will be stated somwhere either as a mark or by a dipstick. If you are refering to how much oil to put in before replacing the head then a few squirts with an oil can should suffice. Turn the motor over by hand a few times to make sure it is distibuted evenly then fill up the motor to the correct level.

2: Replacing rings can be done carefully by gently fitting one end over the piston and easing the ring over in small sections at a time. Careful here as they are very brittle. Be aware that if there is a ridge at the top of the barrel you will end up with broken rings so remove any ridge with a de-ridging tool. Refitting the piston is done from the bottom as there is a slight lead in to the bore...fingers and gentle pressure is all that is needed with attention to keeping the ring compressed enough to enter the bore.

3: Piston heads can be gently scraped clean using a piece of allumuinium...try softing any build up first with fuel overnite. Be careful not to scatch the top or you will end up with a hotspot. A final polish with autosolve polish will help prevent future build up. Be very well warned here! if you do not remove ALL traces of polish afterwards you will greatly increase wear.

4: Carbs can be difficult but on your bike should be fairly simple and, afterall, you only have one. Be careful with small jets as they are very easy to damge. Also do not poke any wire through them. A proprietry carb cleaner and an over night soak will suffice for most internal bits. A digital camera for correct placement on re-assembly will help greatly.

5: A manual impact driver should be a lot cheaper than $80. Soak the screws over night with WD40 or similar and then carefully remove them. Once you have them out cut a straight slot in the top to aid future removal....a junior hacksaw is good for this. If it is not possible to remove them and they are not recessed then get a chisel and hammer them around to the left to release them. be careful if you choose this course not to damage any surrounding covers etc.... If recessed then carefully drill the top in two or more increasing sizes untill the top comes away and the cover can be removed. Then remove the small section left behind with some vice grips.....make sure you get plenty of penetrating oil in there to prevent the bolt breaking off in the hole. As to should you or should you not...only you can answer that question....is there a need to do it? if so do it!

Hope this helps

Good luck
 

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Hey Edowardo -- I just bought a Suzuki FA50 myself, and I'm going to restore it this summer. I'm just wondering how everything went with yours, and if you have any tips or suggestions for me. Thanks.
 

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Hold the phone... No oil in the crankcase? I've never had a bike 2-stroke or otherwise that didn't take oil in the crankcase. I may be confused but we are talking about the lubrication for the entire bottom end correct? What I can find from a quick search says between 500-550ml of 20w50.
 

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2-Stroke M/C engines use oil & fuel mix to lube the crank, rod & piston/cylinder so there is no oil in the "crankcase". When you drain oil from a 2-Stroke M/C engine it is from the transmission and not the "crankcase". On most 4-Stroke M/C engines the "crankcase" and transmission share the same oil.
 

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Two stroke engines do not have oil-tight crank cases, as the crank case is used to pressurize the fuel/air charge so it flows up to the combustion chamber when the intake port is uncovered as the piston bottoms out. But yes, make sure you have oil in the transmission.
 
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