no spark

Today I tried to fire up the Sparta (w/Sachs engine) moped that I just bought and it wouldn't turn over. I think that I'm not getting a spark from the plug. I replaced the plug already so I know thats good. Anyone have any troubleshooting suggestions?

Thanks,

Craig

Re: no spark

Don Pflueger /

a no spark issue can be caused by many things. the first and easiest thing to try is to install a new spark plug. if that does not help, the next easiest thing is to check the tail and brake light bulbs. if they are good, test the spark plug boot for continuity. then check the spark plug wire, points, condensor, and the charging coils. most often dirty or misadjusted points are your problem. on a point type system it is usually a good idea to take everything apart and clean it up. a small amount of rust on the stator plate or charging coils can cause a lot of trouble.

cdi type ignitions either work, or they dont. so if a new plug and good brake/tail lights are not the cure, then chances are the cdi is bad.

with both types of ignition systems, you still need to make sure that all wires are in good shape, connections are clean and tight, and all grounds are hooked up, clean, and tight.

_________________

Re: no spark

Don Pflueger /

if its not spark, here are some other ideas from my repair forum.

http://www.1-2-free-forums.com/mf/mopedonly-forum-2.html&sid=b619f688e2ac738b8c6ae32d9a981279

Re: no spark

What do you mean it would not turn over? the engine is seased or do you mean the Engine did not start it could be a bad Condenser or Wiring or Ignition Coil or a old faulty Plug Cap and Wire.

Re: no spark

Thanks for the tips guys, I've just downloaded dempsey's repair manual to learn a little something about how electrical systems work. Eventually I should get to the root of the problem. When I said that "it wouldn't turn over" I just meant it wouldn't fire, the engine does not seem to be seized. Thanks again for the help.

Craig

Re: no spark

Get a can of Starter Fluid.. if a little squirt into the carb air-intake or the spark plug hole gets it started, ignition is ok but fuel delivery is restricted.

Re: no spark

Don Pflueger /

remove the airbox and filter. spray some carb cleaner into the carb throat. close the choke. try to start the engine.

if it fires, you have a fuel problem. start at the gas cap and clean the vent. next, make sure the tank is clean and the gas is fresh and mixed to the correct ratio (if applicable). make sure the filters and valve are clean in the petcock. check the fuel lines for any kinks or blockage. remove and thoroughly clean the carb, useing a piece of wire and carb cleaner. run the wire thru every hole that you can find in the carb body and all its parts. follow up with blasts of carb cleaner.finally, make sure the reed valve is clean, and tight (if your bike has a reed valve).

if it does not fire, then you have either an electrical, or a compression problem. remove the spark plug. insert the spark plug into the spark plug boot. hold the base of the plug against the engine block. turn the engine over as if you were starting it up.

if no spark is present, try a new unused spark plug.

if no spark is present with the new plug, then check the simple things first. alot of bikes must have a good brake and tail light bulb in order to get spark. test the bulbs condition. if bad, replace with a new bulb. if good, then check the magneto. points are a very common item to fail. and most times its because they are dirty, or out of adjustment. clean them with an emory board or a point file. NEVER USE CARB CLEANER! blow them out good with compressed air. an average gap to set the points to is .014"-.018". you can find your actual timing and gap settings for your particular engine in service manuals located at www.mopedriders.org in the moped repair section. coils rarely ever go bad. but, if the magneto is full of rust, every thing needs to be taken apart and cleaned. surface rust on the pick ups for the charging coils, and on the magnets can and will affect spark. make sure the wire from the ignition (ht coil) coil to the spark plug is in good shape. check the spark plug boot for continuity, especially if it is aresistor type boot. and if it is a resistor type boot, do not use a resistor type spark plug. lastly, check all wire connections to ensure they are clean and tight. on puchs, make sure the horn is hooked up.

if it has spark, then you have acompression issue. all 2 strokes must have at least 120 lbs of compression to run. so use a guage to test the compression. if less than 120 lbs, you must find where it is going. the usual places are, rings, head gasket, cylinder base gasket, intake manifold (where it mounts to the cylinder), or crankseals. a leak down test can be performed by any reputable lawn mower, auto, or motorcycle repair shop to tell you exactly where your compression leak is and how bad it is. replace or repair the bad parts.

if compression is higher than 120 lbs, pull the exhaust system off and make sure the port and the pipe are clean. these two things will prevent starting.

_________________

donp

Dons Ride-Ons

used bikes

1695 Sunview dr

Lyndhurst, Ohio 44124

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