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Hey everyone,

I just bought an '84 honda nighthawk w/27,000 miles on it as a project bike. The previous owner said it had a problem with slipping out of second gear. Unfortunately the bike was not running when I bought it (needs a cam and an alternator chain) so I can't reproduce the problem to see how bad it really is. I've got the crankcase split right now and have access to the entire transmission but being this is my first motorcycle and the first time I've ever torn into a transmission (I previously worked only on car engines) I don't really know how to tell defective/problematic transmission parts from good ones. The dog teeth on second gear look a little rounded on the edges but that's all I can really tell. I've read the nighthawks commonly had problems with second gear but couldn't find any details on what the cause was. If someone could give me tips or advice on what to look for I would really appreciate it. I can take pictures of parts if anyone needs to see them as well.

Alternator shouldn't have a chain.

If the dogs on 2nd look the same as the dogs on the rest of the gears that isn't the problem. You're going to want to look at the grooves in the shift drum to see if anything is chipped or worn down/away. That will also cause an incomplete shift.

Pictures would help... and are you sure that you're examining second gear (no offense, but I get really confused in there sometimes too, and it's possible that you're looking at 4th or something instead of 2nd and thinking that it's okay when it's not.

So, without pics, we're sorta stuck.

My 91 Nighthawk 750 has an alternator/starter chain. The DOHC 750 Hondas have the alternator above the tranny, chain driven.

:O cool. Something new every day. I apologize.

Hi,

I'm new here and I know this is a bit late but I'm having the same problem with my 84' nighthawk. When I split my crankcase the left shift fork which engages 2nd was worn leaving about a 16th inch gap in where the fork mates with the gear. I replaced it put it all back together and went for a ride. The bike didn't accelerate well and I couldn't get it to go over 50mph. I put it on its center stand and heard a chugging noise coming from the tranny. I took it all back apart and found a little wear on the left shift fork up by the part number which would mean things were out of alignment because the gear that locks into the fork was rubbing on it. Someone told me to check the drum (which is fine) and that I would need to replace the gear that the fork rides on because the knobs that lock into the other gear are round which cause it to continuously kick out and the gears to the left and right of it. I am currently waiting on parts and am curious if this will solve my problem. Also I am wonder how often this happened on the Nighthawks. I got mine for free for and rebuilt and repainted the entire thing and it had around 21,000 miles on it. Any help or suggestions would be great.

I had a similar problem with my 83 650 nighthawk. Turned out it was the shifter fork which then caused some wear on the gears. I found that 83 550 nighthawk parts fit just fine. I wonder if it is the same for the 750. Lots of tranny parts for these bikes are discontinued( honda doesn't make them anymore) so if you can fgind a parts bike get it and keep it. That if you want to keep one of these fine bikes.

Bent shift forks are common on all makes. Mostly caused by riders trying to shift fast. They jam the forks and then it never shifts right again. Unrepaired, the dogs on the gears wear at an angle and then it starts to pop out of gear.

I've rebuilt a couple of MC tranny's already for myself and friends. Second gear is the most common to go, as the trip through neutral slows the shift and thge rider pushes harder to shift faster.

When replacing shift forks, inspect the gears carefully, as they are usually damages too.