Motorcycles, Snowmobiles, Go-Carts, ATV's and Golf Carts - Not getting a spark...
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dangregory007
07-24-08, 09:01 PM
Hi guys,
Sorry this rambles a bit at the start, I just don't want to leave out any details that may be relevant
I've got a 1980 Yamaha SA50 Passola that I've just rebuilt for a Mopedathon (6hr endurance race, its great :D )
It struggled through the last one, so I've stripped and reassembled the majority of things, except for the flywheel generator section, as I don't have the special tool required to get it out.
I've taken all the lights, horn etc off as I don't use the moped on the road, and I've also removed all wiring that isn't required, while consulting with the schematic in the Haynes manual. It's a kickstart model, so I've also removed the battery.
I finished rebuilding the engine today, kicked it over, got plenty of fuel flow into the cylinder, but no spark (as far as I could tell)
The bike was running before I stripped it, although it took a hell of a long time to start
I've checked all my wiring, and its all correct. Which leads me to think its one of the generating parts in the engine.
Am I right in thinking that I don't need the battery at all? It was going fine without it before, but could it be harder to start without it somehow?
After kicking it over for a while, I removed the spark plug (HT still attached) and check the electrical connections. When I plugged one back in, I got a spark. I managed to replicate this once more, back haven't been able to again....
How can I test for sure if it is sparking or not? If I just pull out the spark plug and attach it to the HT lead, should I see a spark when I kick it over, or does the outer need to be grounded to the engine?
This is very frustrating, if anyone has any ideas I'd be stoked, cheers!
- Dan
Sorry this rambles a bit at the start, I just don't want to leave out any details that may be relevant
I've got a 1980 Yamaha SA50 Passola that I've just rebuilt for a Mopedathon (6hr endurance race, its great :D )
It struggled through the last one, so I've stripped and reassembled the majority of things, except for the flywheel generator section, as I don't have the special tool required to get it out.
I've taken all the lights, horn etc off as I don't use the moped on the road, and I've also removed all wiring that isn't required, while consulting with the schematic in the Haynes manual. It's a kickstart model, so I've also removed the battery.
I finished rebuilding the engine today, kicked it over, got plenty of fuel flow into the cylinder, but no spark (as far as I could tell)
The bike was running before I stripped it, although it took a hell of a long time to start
I've checked all my wiring, and its all correct. Which leads me to think its one of the generating parts in the engine.
Am I right in thinking that I don't need the battery at all? It was going fine without it before, but could it be harder to start without it somehow?
After kicking it over for a while, I removed the spark plug (HT still attached) and check the electrical connections. When I plugged one back in, I got a spark. I managed to replicate this once more, back haven't been able to again....
How can I test for sure if it is sparking or not? If I just pull out the spark plug and attach it to the HT lead, should I see a spark when I kick it over, or does the outer need to be grounded to the engine?
This is very frustrating, if anyone has any ideas I'd be stoked, cheers!
- Dan
marbobj
07-25-08, 05:43 AM
To check for spark use a good plug and ground it to the engine, kick it over. It's easier to see in the dark of a closed garage, though.
Depending on the system a battery can make a big difference. A 1980, I can't tell you what's in it. Mid seventies to 80's were the years conversions were being made to capacitors. Yours may be on either side of that conversion.
Some systems have a capacitor that is fed by the battery. That builds and is triggered by a signal generator or sensor. From the capacitor it goes to the coil for the high energy voltage for the spark. Other systems are more of magneto setup where the mag feeds an ignition module = coil/capacitor combination. Those are in a lot of the small engines = lawnmowers, chainsaws, etc.
When you see something like that in a small bike, the charging system may feed the battery and its accessories while the ignition system is actually running parallel to the other electrical system. Or the two could be integrated depending on the system.
If you go back to the other side of the conversion years to the point/condenser/separate coil, that system is a battery fed by the charging system. Then the battery feeds the ignition. In that setup, the engine will run without the battery, but it's difficult to start. A battery provides much more current on demand than a charging system at a given point = stronger spark =better starting.
Automotive systems with alternators and computers are another story.
Depending on the system a battery can make a big difference. A 1980, I can't tell you what's in it. Mid seventies to 80's were the years conversions were being made to capacitors. Yours may be on either side of that conversion.
Some systems have a capacitor that is fed by the battery. That builds and is triggered by a signal generator or sensor. From the capacitor it goes to the coil for the high energy voltage for the spark. Other systems are more of magneto setup where the mag feeds an ignition module = coil/capacitor combination. Those are in a lot of the small engines = lawnmowers, chainsaws, etc.
When you see something like that in a small bike, the charging system may feed the battery and its accessories while the ignition system is actually running parallel to the other electrical system. Or the two could be integrated depending on the system.
If you go back to the other side of the conversion years to the point/condenser/separate coil, that system is a battery fed by the charging system. Then the battery feeds the ignition. In that setup, the engine will run without the battery, but it's difficult to start. A battery provides much more current on demand than a charging system at a given point = stronger spark =better starting.
Automotive systems with alternators and computers are another story.
dangregory007
07-25-08, 05:34 PM
Wow thats brilliant, thanks for the quick response!
Mine has a CDI, so I believe its of the capacitance type?I'll give it a go with the battery back in then, although I have no idea where the rectifier is :confused: Am I right in thinking I need the rectifier to charge the battery?
Cheers
- Dan
Mine has a CDI, so I believe its of the capacitance type?I'll give it a go with the battery back in then, although I have no idea where the rectifier is :confused: Am I right in thinking I need the rectifier to charge the battery?
Cheers
- Dan
marbobj
07-25-08, 05:54 PM
Brilliant would definitely be an overstatement. :D
But....
Yep, on the rectifier to charge the battery. If it's CDI it will have the capacitor. There are other variations that use capacitors that don't always carry a CDI label. What you have could very well draw from the battery to charge the capacitor, then you would have a signal generator of some type to trigger a discharge = CDI to coil (high voltage spark) to spark plug.
But....
Yep, on the rectifier to charge the battery. If it's CDI it will have the capacitor. There are other variations that use capacitors that don't always carry a CDI label. What you have could very well draw from the battery to charge the capacitor, then you would have a signal generator of some type to trigger a discharge = CDI to coil (high voltage spark) to spark plug.
dangregory007
07-25-08, 10:07 PM
Well its more than I knew in the first place ;)
I'll see if I can find that rectifier, else I'll have to make one as I don't think I'll be able to find a spare! According to my Haynes manual its a CDI, so thats all good. Yep there is a trigger wire that comes off the flywheel generator.
Hopefully once I get the battery and rectifier back on I'll have a bit of luck, cheers!
- Dan
I'll see if I can find that rectifier, else I'll have to make one as I don't think I'll be able to find a spare! According to my Haynes manual its a CDI, so thats all good. Yep there is a trigger wire that comes off the flywheel generator.
Hopefully once I get the battery and rectifier back on I'll have a bit of luck, cheers!
- Dan
marbobj
07-26-08, 07:13 AM
Hang in there!
A lot of those things are more fun to fix than they are to use. If you can't find the rectifier in your Haynes, try Bike Bandit or Cheap Cycle Parts for an exploded diagram of your bike. Most of the Yamaha engines of that size and year, although not your model, should have the same parts.
6 hours on a moped :eek: - that is amazing!
A lot of those things are more fun to fix than they are to use. If you can't find the rectifier in your Haynes, try Bike Bandit or Cheap Cycle Parts for an exploded diagram of your bike. Most of the Yamaha engines of that size and year, although not your model, should have the same parts.
6 hours on a moped :eek: - that is amazing!
dangregory007
07-26-08, 10:28 PM
SUCCESS!!!
I made a schoolboy error of not checking connections, and as it turned out one of the plugs wasn't connecting properly, and it happened to be the signal wire :)
I then had another problem though - the bike was going, but as soon as I put any weight on it, it would cut out which was pretty random. After playing with it for over an hour I realised that the engine was sparking onto the chassis when I put weight on it, therefore moving the chassis nearer to the engine, this must have been stealing the spark away from the spark plug, so a quick connection between engine and chassis and now its going sweeeet :)
Yeah the mopedathon is great fun, its teams of 3 so its not too painful. We have it every 6months here on the AirForce base where I live/work, and the track is a decent size. I think the max laps over 6hours was about 150 last time
Thanks for your help
- Dan
I made a schoolboy error of not checking connections, and as it turned out one of the plugs wasn't connecting properly, and it happened to be the signal wire :)
I then had another problem though - the bike was going, but as soon as I put any weight on it, it would cut out which was pretty random. After playing with it for over an hour I realised that the engine was sparking onto the chassis when I put weight on it, therefore moving the chassis nearer to the engine, this must have been stealing the spark away from the spark plug, so a quick connection between engine and chassis and now its going sweeeet :)
Yeah the mopedathon is great fun, its teams of 3 so its not too painful. We have it every 6months here on the AirForce base where I live/work, and the track is a decent size. I think the max laps over 6hours was about 150 last time
Thanks for your help
- Dan