Topic: Any Suggestions for 1983 Honda Nighthawk ignition problems?

[kwalt]

Yesterday I brought my Nighthawk out for the first time in two years.  It started after about 2 minutes and then died.  I had to charge the battery for an hour before I could start it again.  After it was started the second time I drove it for about 25 minutes before it died at a stop sign and would not restart even after a battery charge.  The motorcycle was transported home, the battery was charged today but would not start.  After several attempts to start were unsuccessful I pulled out two spark plugs and found that neither of the plugs were not firing.  Sounds like an ignition problem to me.

Any suggestion for what to check next?

[Danno]

check for a gummed up carb the nighthawks came with cv carbs and they have a lot of small orifices in them that can gum up in a very short time but i would sooner believe that your float is sticking open and flooding the cylinder and puting out the spark next time yu store it if you are not going to drain all the gas out of it then you should run some sea foam or some other form of gas stabilizer through it it will save you a lot of headache the next time count yourself lucky though my fathers valkirie has 6 carbs of this type and they will plug up if left out of service for more than a month

[GrandRapids750K3]

Did you try grounding the plug to the side of the engine to be sure your getting a spark? Would at least rule out coils...

[78 k550]

you might need a new battery would be my guess.

Paul

[cb650]

I have a 84 sitting for parts if you need anything.

[MoMo]

I believe the Nighthawk uses the same code as the sohc so check for 12v at the black/ white wire going to the coils, but first make sure the battery is good-does it read close to 13 v after a full charge?

[LArzFroMArz]

Just having done one of these myself once you check the normal things like carbs and coils you are basically left with the CDI or spark box. Electrically it is "upstream" of the coils so no spark could be either coil or CDI. Coil checks with an ohm meter are easily done but there is no shadetree testing for the CDI. My 2 cents is on the CDI going t*ts up.
Larz

[GrandRapids750K3]

So the bike is now running, but still not holding a charge. My thought is that the the rectifier/regulator is no good. Can anyone tell me the tests I need to do with my multi meter? What AC and DC numbers should I be looking for? Where should I do the tests at? Would like to know for sure before any money is spent on new parts...

CB650- got a good rectifier/regulator on that 84?

[cb650]

Its still there.  Bike blew a rod when parked so electrics was good.

[andrewk]

Nighthawk uses dohc charging and ignition system.  Could be a spark issue, but i would be checking the charging system first.  Shorted rotor and a flat battery will provide intermittent spark.

[grcamna2]

Rectifiers are weak on those.

[GrandRapids750K3]

CB650- what would you need for it shipped to 49505?

[cb650]

Nighthawk uses dohc charging and ignition system.  Could be a spark issue, but i would be checking the charging system first.  Shorted rotor and a flat battery will provide intermittent spark.

Not the 82
GrandRapids750K3  pm sent