• I am hoping you, or one of the readers of your home page can help me solve a problem I am having with my bike. I just bought it used with about 7800 miles on it. The battery is approx. two years old. The problem is that the bike's charging system does not seem to be working unless the engine is turning at a high speed (6000+ rpm.). After the battery was charged by the local Honda dealer (it had died and left me stranded), the bikes electrical system was checked and they said it was OK. I rode the bike yesterday, about 100 miles non-stop at mostly highway speeds. The engine was running at about 3500 to 4500 rpm. for most of the ride. Just before getting home the liquid crystal fuel and gear position indicator began to blank out. They would come back on if I rev'ed the engine to about 6000 rpm. A few miles later, as I pulled into my drive way the bike died (dead battery). I suspect that the bike has one or more of the following:

  * A battery problem

  * A short circuit somewhere

  * A problem with the electrical charging system (alternator?)

• Update-- The bike is back in the shop again (for the fourth time). So far it has a new voltage regulator/rectifier unit and a new battery. It passes all the tests of the charging system (both static and dynamic) with flying colors. Only problem is that after riding for a while, even at highway speeds, the battery goes dead. The dealership's service department assures me that this time they will find the problem, even if they have to send a mechanic out on the bike with a chase bike and run it till it dies. I will keep you posted, especially after I am confident that the problem has really been solved.
• Well, here is the latest. The dealership's service writer called and told me that after running the bike extensively, they had finally gotten to the bottom of the bikes electrical problem. It seems that the alternator's stator is putting out greatly variable amounts of AC current. So much current in fact that it has fried the new voltage regulator/rectifier unit they had previously installed. After checking with Honda America, they have concluded that the stator needs to be replaced and that it was the root of the problem. It will take 7-10 days to get the new stator assembly (an updated/improved unit) and a new regulator/rectifier unit. After they get the new parts they plan on running the bike extensively again. He said that after replacing half the electrical system, he wants to make real sure everything is working right. So far, this problem has cost me about $700, counting the expected bill for the new stator assembly. The only good news is that because the new regulator/rectifier unit had fried, they were able to cover all this latest diagnostic and trouble shooting work under Honda's new part warranty.
• Well, after an extensive test ride today, I have concluded that the bike's charging system problem has been fixed. The dealership ended up replacing the alternator's stator assemble, the voltage regulator/rectifier (for a 2nd time), and the ground strap. I also replaced the battery. The bike runs great now.

• Original problem as posted on "Needs Help' page:
  • I am having final gear oil come out of the final gear breather tube on my '83 650. It has been happing since I bought the bike last fall. I have changed the oil twice and am now running Bel Ray SAE 90 Final Gear Oil. The oil either splashes, foams or somehow is getting to the breather cap in liquid form. It then runs down the outside of the final gear case and gets thrown on the tire and wheel. I cleaned the bike recently and my wife and I took a short 5 Mile ride to a restaurant and there was oil all over the place.
• One possible solution: Gear lube spewing out of vent on rear wheel gear case--I had this problem on 2 different 83's. The fix was the same in both cases. Drain the existing lube out of the rear end. If you have the luxury of time give it a few minutes to drain thoroughly. Go to your local marine dealer or auto parts supplier and get the correct weight marine gear lube. Following the directions in the owners manual carefully fill the rear end with the marine lube. DO NOT OVERFILL. The difference is that the marine lube (for outdrives) has an antifoaming agent in it which keeps the stuff from barfing out of the breather vent. If you overfill it, it will barf regardless of what you use. Ken Siadak
• The solution that ultimately worked: Lots of people sent me advice on my rear drive oil leak (listed on your owners need help page), most people told me I had too much oil or that the oil was foaming. I found a local dealer who told me that it was that the breather which could not handle quick ambient pressure changes. He told me that the problem would appear when the bike has been in the cold and is suddenly run and gets hot. This quick temperature change raises the pressure in the gear case and that pushes oil out of the breather. It is not foaming since it happens intermittently and not when the bike is run for long periods.

  Best advice came from Ron Pergl [pergl@gg.clayton.edu]. "Had the same problem with my Nighthawk just after I got it 5 years ago. I checked with the local Honda dealer, and the old owner said there was a recall on these rear end vents and a re-designed vent was available. I got one from him ($10) and installed it myself. Have had no problems at all since then. Hope this helps."

  I followed up on his advice and talked to a different dealer that then looked up the breather and ordered one for me. They ordered the vent for me and when it came in it was the exact same!!! With further research it appears that Honda lists both the original vent cap and the redesigned vent on the microfiche. It took some research to find out that the correct part number is 41306-ME5-305. If anyone else wants this part I advise ordering the part by the above number! The new vent cap has a valve in it and looks identical until you try to install it. The replacement cap will stick up higher and will not mate with the casting on the gear case. I did not realize this and bent it trying to get it to go down. Also the tube that goes into the casting is slightly smaller diameter so you have to squeeze the tube to slightly oval so that it will not fall back out. So far it has appeared to solve the problem.

  Ian Ellis Welsh Companies (612) 897-7802

I am on my 2nd 83 650sc. 1st one went w/my son when he moved out. This tip may save someone a $ or 2. We lost all spark on our machine. A couple of calls to local shops resulted in the usual "bring it in and we'll look at it for $45 per hour". Closer inspection noted that the brass looking connections on the ingnition box under the seat appeared to be slightly corroded.

Reseating the connectors on the box resulted in spark. Problem solved for about a week or so. Re-seating connectors is getting old at this point. Used box in salvage yard was quoted at $250.00. U got to be kidding!!!!

Fix was to carefully disassemble the factory connector , clean the female spade lug connector, bend SLIGHTLY the rounded ends, then re-assemble the connector. The connection on the spark box was also carefully cleaned and then coated w/silicone grease. End of problem. The connectors can be removed from the nylon shell using a small jeweler's screwdriver to depress the tab which lock them in place. Caution-- patience-- are the watch words w/ this fix.

Also had some problems with the original spark plug caps. Previous owner had somehow managed to destroy them. New wires go for $20.00 EACH!!!!. NGK makes a really nice aftermarket plug cap that has proven to be just the ticket.

  I saw your Nighthawk web page and thought you might be interested in an ignition fix that was done to my 83 650 Nighthawk. It had no spark and after troubleshooting I narrowed the problem down to the ignition module. Honda, in Lynchburg, VA, wanted $269 for a replacement. I mentioned the problem to a friend at work and he told me to bring it in for him to look at. He's quite good with electronics. He told me he couldn't find anything obviously wrong but suggested that I replace the electrolytic capacitors on the circuit board. They tend to dry out with age and could be the problem. I did as he suggested and found 2 out of 6 on the board to be bad. After I soldered the replacements in and reassembled the connectors to the board the ignition worked. I've put about 4000 miles on it since then and it runs well. I believe this fix could help a lot of people with moderately old ignition modules on all makes of bikes. The replacement capacitors are cheap and worth trying before spending a large amount on a new, or even used, ignition module. I hope this is helpful to someone and saves money for anyone who might have the same problem.

 Frank G. fgad@ibm.net

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