I've got an old 49cc 2-stroke engine on a moped, and it hasn't run for a couple of years at least. The last time the previous owner tried to start it, it didn't run.
I've taken the carb apart and totally cleaned it, all the moving parts work as they should, etc.
I'll be trying to get the motor running again for the first time and I'm wondering what things I should consider while trying. Things like what height the needel should be in the carb, do I have a better chance running it rich or lean (avg. tempuratures are about 15 degree celsius here), should I run it with more or less oil than regual?
Another potential problem is that it's a pedal start moped, and I don't have the wheels on it, which means I'll be turning it over by hand. Hopefully I'll have enough strength to turn it over, but more than that, is there a danger that the pedal will whip around and smack me in the hand again?
Anything else I havn't thought of?
Thanks
Getting a 2-stroke running...
When I got my MB5 the engine (a 50cc oil injected 2-stroke) hadn't been started in a few years. I drained the tank and filled it, started it with the kickstarter, and sprayed carb cleaner into the intake. It started just fine and runs just dandy.
The kicklever should have a ratchet on it, and two-strokes don't have alot of compression.
I'm not sure about how to deal with the colder temps, I'm a Florida boy.
The kicklever should have a ratchet on it, and two-strokes don't have alot of compression.
I'm not sure about how to deal with the colder temps, I'm a Florida boy.
Do dyslexic people poder the existance of Dog? Do computers ponder the existance of man?
I miss the simplicity of two strokes.
Sorry I don't have much advice, never had to do any work on mine - it was a 175cc scooter with over 20 years of riding and it was rock solid.
A 49cc engine is not gonna be much effort to start by hand. Is the spark plug firing at all - that's about the only problem I ever had.
Sorry I don't have much advice, never had to do any work on mine - it was a 175cc scooter with over 20 years of riding and it was rock solid.
A 49cc engine is not gonna be much effort to start by hand. Is the spark plug firing at all - that's about the only problem I ever had.
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BuzZz
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Cleaning the carb was a good start. Put the clip back in the same groove it was in when it came apart.... if you really have no idea where it was, put it in the middle and work from there.
Turning it over by hand should be no more dangerous than starting it with your foot...... but it's never a good idea to get your face too close to an operation like this, so be careful.
Your not gonna be able to really tune or jet the thing untill you get wheels on it, just just get it running and then rolling. Then you can set the carb properly.
2 strokes are simple and pretty reliable in scooter-tune, so you should be buzzin round on it shortly. Have fun with it.
Turning it over by hand should be no more dangerous than starting it with your foot...... but it's never a good idea to get your face too close to an operation like this, so be careful.
Your not gonna be able to really tune or jet the thing untill you get wheels on it, just just get it running and then rolling. Then you can set the carb properly.
2 strokes are simple and pretty reliable in scooter-tune, so you should be buzzin round on it shortly. Have fun with it.
No Witnesses.... 
It's a Sachs, 1978. Similar to Puch.
I'll raise the back onto a block so I can make full revolutions with the pedals, then be prepared for a nasty pedal whip, just in case.
Looks like I've got everything I need to get it going. The gas tank is really rusty on the inside, so untill get that cleaned, I'm using a pop bottle to hold a small amount of fuel/oil. The drive sporket in the engine is missing a tooth or two as well, but i've got 2 of these engines, so i'll take it appart and replace it with an identical one.
It's my first 2-wheeled motor-driven possesion, and I love it.
I'll raise the back onto a block so I can make full revolutions with the pedals, then be prepared for a nasty pedal whip, just in case.
Looks like I've got everything I need to get it going. The gas tank is really rusty on the inside, so untill get that cleaned, I'm using a pop bottle to hold a small amount of fuel/oil. The drive sporket in the engine is missing a tooth or two as well, but i've got 2 of these engines, so i'll take it appart and replace it with an identical one.
It's my first 2-wheeled motor-driven possesion, and I love it.
Well, i've tried, and it doesn't work.
The carb leaks fuel like crazy. I might have figured out from where and I'll see if I can fix it. Fuel is comming out of the jet in a fine mist, wich is good, although maybe it's too much? I don't know.
The cylinder wall is wet with fuel on the intake side, but the spark seemed dry, and i couldn't really tell what was going on on the exhaust side. I thought i saw a couple of plumes of smoke comming out, but only twice, and extremely faint.
I know it's very dirty inside the cylinder too. So far, my idea is that when the fuel goes into the crankcase for compression, all the pressure is being lost into the clutch assembly, as if there's a bad seal somewhere. If that's the case, my only option is to take the whole thing apart...
The carb leaks fuel like crazy. I might have figured out from where and I'll see if I can fix it. Fuel is comming out of the jet in a fine mist, wich is good, although maybe it's too much? I don't know.
The cylinder wall is wet with fuel on the intake side, but the spark seemed dry, and i couldn't really tell what was going on on the exhaust side. I thought i saw a couple of plumes of smoke comming out, but only twice, and extremely faint.
I know it's very dirty inside the cylinder too. So far, my idea is that when the fuel goes into the crankcase for compression, all the pressure is being lost into the clutch assembly, as if there's a bad seal somewhere. If that's the case, my only option is to take the whole thing apart...
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BuzZz
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Leaky carb could well be a stuck needle valve overfilling the floatbowl of the carb. That could be flooding the motor out.
If the crankcase is leaking, it won't run. Well it might run once, then melt the rings due to excessive air sneaking in and leaning the mixture.
How are you mixing the oil and gas? By hand in your fuel tank or is there an auto-injection system on it? If an auto inj., is it primed and pumping? It won't keep it from running, but no oil will kill it quick if you do get it running with out it.
If the crankcase is leaking, it won't run. Well it might run once, then melt the rings due to excessive air sneaking in and leaning the mixture.
How are you mixing the oil and gas? By hand in your fuel tank or is there an auto-injection system on it? If an auto inj., is it primed and pumping? It won't keep it from running, but no oil will kill it quick if you do get it running with out it.
No Witnesses....
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Quick 350
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I had a few Mopeds with the Sachs engines on them as well as a 78 Columbia that must have been identical. (Now that I think of it Sachs only had one engine design)
The carbs are no big deal Classic Cycle Parts has a rebuild kit for $8.00 shipped it's the same as my 77 Puch carb and I just ordered & installed one.
Starting off in the middle with the needle is the best way to go, Float valve should be set at 0.65",
One other thing you might want to do is pull the exhaust and give it a good cleaning.
One thing I've found on all mopeds is no matter how long they have sat the exhaust will be filled with crap.
Starting it first with the exhaust off will be fine just don't rev it or try to ride it with out the exhaust.
Get a new plug don't even fool around with the one it came with $2.00 at the most any ware.
if you don't have a wheel on the back to start it by then taking the magneto cover off and using you foot to turn it over works real well.
Good Luck!!!
and post back!
Mike
The carbs are no big deal Classic Cycle Parts has a rebuild kit for $8.00 shipped it's the same as my 77 Puch carb and I just ordered & installed one.
Starting off in the middle with the needle is the best way to go, Float valve should be set at 0.65",
One other thing you might want to do is pull the exhaust and give it a good cleaning.
One thing I've found on all mopeds is no matter how long they have sat the exhaust will be filled with crap.
Starting it first with the exhaust off will be fine just don't rev it or try to ride it with out the exhaust.
Get a new plug don't even fool around with the one it came with $2.00 at the most any ware.
if you don't have a wheel on the back to start it by then taking the magneto cover off and using you foot to turn it over works real well.
Good Luck!!!
and post back!
Mike
Alright, so the update is I got it running! I re-assembled it with the choke, as well as put the seat and both pedals on, so i could sit on it and crank it continuously. After a few intermitent pops, it started running smooth. What a sense of accomplishment.
Then it died...
I tried again, and the clutch cable broke, so that sucked. I found a cable that was appropriate and fit it on, and tried again, it ran again, but:
The carb is still flooding like crazy, I suppose it could be the float, but i'm not sure how to change that. What's the 0.65" setting? I dont' remember seeing something adjustable like that.
I'll check Classic Cycle Parts to see if they've got what I need. Thanks.
What new plug did you mean?
As I got it running, I didn't run it with an exhaust, and I only reved it to make sure it didn't die, but I havn't run it for more than 15 seconds yet. The reason for that is that it almost just starts revving itself. It'll start a little slow, and then get faster and faster. I'm sure my neighbours hate the noise. I remember having the needle height on the second most open of 4 settings, maybe I'll drop it one. I don't think the throttle is stuck though. What could be revving it so high? No load? The drive sporket is also contantly turning.
Definatly a few things to tune, but it runs!
Then it died...
I tried again, and the clutch cable broke, so that sucked. I found a cable that was appropriate and fit it on, and tried again, it ran again, but:
The carb is still flooding like crazy, I suppose it could be the float, but i'm not sure how to change that. What's the 0.65" setting? I dont' remember seeing something adjustable like that.
I'll check Classic Cycle Parts to see if they've got what I need. Thanks.
What new plug did you mean?
As I got it running, I didn't run it with an exhaust, and I only reved it to make sure it didn't die, but I havn't run it for more than 15 seconds yet. The reason for that is that it almost just starts revving itself. It'll start a little slow, and then get faster and faster. I'm sure my neighbours hate the noise. I remember having the needle height on the second most open of 4 settings, maybe I'll drop it one. I don't think the throttle is stuck though. What could be revving it so high? No load? The drive sporket is also contantly turning.
Definatly a few things to tune, but it runs!