Need suggestions for trouble shooting my motorcycle engine

jpeter · L Plate Warrior Joined: 16 May 2004 Karma :

Can't start my 83 nighthawk 550. Trouble began when she would fail to rev past 5000 rpm. It would shut off like I had hit the switch. Let the rpm drop to 4500 and the engine would kick back in and run normally. It got worse until it quit on me entirely. I shot gas into the air intake thinking if it would fire on a direct shot gas the trouble would be fuel related. It wouldn't fire. Hooking up a spark plug outboard shows a faint spark but not strong enough to fire off my clamp-on timing light. Should the light blink, which it did a time or two, a cylinder or two will fire. I changed out the cdi unit with a used one which I have the option to return. No improvement. Whats next? Any suggestions for testing the pickup? Any Ideas at all would help a lot. Crying or Very sad

I so miss my little Nighthawk.
____________________
Jim

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

Get the coils tested, they could be knackered. If they are ok, get a new HT lead and spark plug.

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

I would be inclined to say the coils as well, but also worth just putting some new plugs in there. It is not that likely to spark at all if the cdi unit is gone

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

jpeter · L Plate Warrior Joined: 16 May 2004 Karma :

First thing I did was replace the plugs. I would be surprised if both coils went together. Its got two pickup coils for timing. I doubt if both of those would go together. I outta check the thing that pulses those coils though. Anybody know how that works?
____________________
Jim

mchaggis · World Chat Champion Joined: 09 May 2004 Karma :

https://www.dansmc.com/MC_repaircourse.htm

This site should be able to help. More specifically,

https://www.dansmc.com/troubleshooting2.htm