1983 Nighthawk CB550SC in the nest.

[Bonz]

Local motorcycle repair shop had a number of bikes dropped off this summer by folks that just didn't want them anymore. No titles otherwise they probably would have sold them.

Owner is a nice guy and friend. So, brought home an orphan 1983 Nighthawk 550 that had sat for the last 20 years. Finally got it road worthy in terms of mechanicals. Still needs to have new turn signals put on it and tires.

Hydraulic valve adjusters so it won't have a tight valve like the Seca 750 ended up with, lol.

Single front brake caliper needed rebuilding, clutch slave cylinder and carbs needed unracking and cleaning as well. Everything went back together like it should and it runs great. However, appearance-wise it looks like it just came out of a dumpster.

The issue that has reared its head now that I've been riding it around a little in the neighborhood, the charging system is not charging the battery. It cranked weak last night when I was going to take it for a ride so charged the battery overnight. Battery checks out fine. 12.7 volts sitting, 12.7 volts with the engine running and raising the rpm. No bueno.

Time to bug out the charging system, my thought is check the connections first, the bike sat 20 years, then rectifier, stators are typically not issues, even after sitting a long time. So the journey continues on a different bike now.

[Socer4m]

Howdy Bonz,,,,that is a cool bike, in its day was a great solid do everything bike. Sounds like you got it going ok,, its amazing how many old bikes get neglected and just sit.... Have fun,,,,,Mike in S.Diego and PA

[Bonz]

Thanks Mike. I bought one from Craigslist 10 years ago, fixed it up, flipped it and made a few bucks. Really enjoyed it when I was riding it for a short time.

That Nighthawk engine is an overachiever. It's a big 550, at 572 cc. It's not a boring bike with respect to the power and acceleration despite the displacement.

When given the opportunity for a free bike, I worked on it with my grown sons and they learned a lot and will be perfect to teach them to ride on, couldn't be turned down. It's running fantastic, but looks like it was pulled out of a dumpster based on exterior condition.

The bike weighs 445 lb wet, definitely on the lighter side of things and low seat height. Perfect for when, not if, it gets dropped learning around the parking lot. Neither one of them has done a manual transmission before.

For what it's worth, the YICS tool was worth it for the Seca 750 in case you haven't seen that other thread. That is the smoothest bike I've ever owned other than the 80SG, which was the same. Both like a sewing machine.

ZRX1200 has that raw edge, I've installed an air fuel ratio gauge and dialed the carburetors in the last couple months, flat out runs with a vengeance now. Teacher friend of mine has a 2026 Yamha R1. Third gear at 40 mph in the R1 is the same RPM as second gear at 40 miles per hour for the ZRX. If I get the jump or if he gets the jump, the gap stays the same until about 95 mph. Then I'm running out of RPM (9,500 rpm, limit is 10,500) and have to shift. The R1 has a quick shifter and 4,000 RPM to go (13,500 rev limit) before he has to shift. Can't keep up with him past that but in the mid-range it's pretty cool to see how well the ZRX is running now for a 25 year old bike. Fwiw, ZRX had its 5th trip of Pikes Peak this summer for the ride.

[Bonz]

Nighthawk battery was not charging. Battery 12.7 volts, engine at 3500 RPM battery voltage was static. Rectifier checked out with the multimeter. Stator had no output with engine running. Nor did any of the three phases have continuity. Need to replace stator.