Author Topic: My accidental 1982 Nighthawk 650  (Read 13276 times)

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Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #100 on: January 09, 2022, 07:57:12 AM »
Finally getting to fixing some of the little stuff. The whole throttle assembly has play in it.

There is a part that goes here that is not on the parts diagram as it is part of the whole assembly. It is broken into 3 pieces.


It has a locator pin on it that should keep the throttle assembly from rotating.
I JB welded it but as expected it broke immediately.


I am looking for it at local salvage yards and eBay but no luck yet.
« Last Edit: September 15, 2024, 05:13:09 AM by cheddarGoblin »
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #101 on: April 12, 2022, 05:00:22 AM »
I ended up purchasing a whole assembly of eBay. (Side note: shortly after, I got whole motorcycle for less than I paid for this assembly :))



All I needed was the piece with the locator pin. I ended up using the whole thing though as the other assembly was cracked and the ebay one was in better shape overall.


« Last Edit: April 12, 2022, 05:05:47 AM by cheddarGoblin »
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #102 on: April 12, 2022, 05:12:53 AM »
I realized I never posted any compression results after the rebuild. It does start much easier and seems to run well. Though there are some noises I am unsure about, I am suspecting one is the cam chain though.

With my el cheapo tester


With the Bosch I purchased. I think this was before I had even started it after the rebuild. So I should recheck it now after I have put some miles on it.

It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #103 on: April 12, 2022, 05:21:05 AM »
The tanks emblems that came with the bike were in rough shape, almost all paint was gone. I had purchased some that were mint but they were form a different bike so didn't fit properly. I thought about trying to heat them up and bend them but didnt think that would turn out well, so decided to repaint the originals. I just used model paint and then shot it with clear.



I was pretty happy with how they turned out.


 
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #104 on: April 12, 2022, 05:38:22 AM »
I know I am getting to the end of the project because I have relatively tedious small tasks now.

Once I put the badges on, I realized I needed to sand the paint from the fins of the head. At least it was an easy job.



With the badges on and the fins sanded, this thing is looking sharp

You can see how my decals didn't quite line up in this one. Oh well.


After taking it for a ride.
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #105 on: April 12, 2022, 02:12:11 PM »
I should have put a new chain on a long time ago. The one that came on the bike was twenty years old and would shed o rings like it was its job. I hadnt done so yet because I thought it would be fine for awhile. But since I am riding it more than taking it apart now, it is becoming more of a problem.

One of the issues has been that the bike would start jerking when in 4th or 5th gear at highway speed. I just assumed that this was because of something carb or engine related. Or perhaps something with the transmission. I had cleaned and lubed that chain quite some time ago and it hadnt seen a lot of miles but I found that it was dry so lubed it again. I issue did seem somewhat improved but not gone completely. After rechecking the chain when I got home, I found some stiff links and what seemed like several bad spots. So it seemed like a new chain was finally in order. This is one of those things that in many years of riding bikes, I'd never really had an issue like this. So I am learning stuff that I probably should have learned a long time ago.

I think these links are a little stiff.


I ordered a chain that was a bit too long.


The old one was stretched by about half a link it seems. I am not sure if that is excessive, I think the stiff links and losing O rigns were more my problem. Which was also the reason that I am not bothering to change sprockets right now.


Adjusted lubed and ready to go


I did use the clip master link. Bottom left there is a link, marked with Sharpie, that seemed bent and kept squeaking when going around the front sprocket, so I flipped the chain over, problem solved.


I can only assume that a PO had the chain break on them at some point as this sprocket cover has a chunk missing.




« Last Edit: September 15, 2024, 05:12:57 AM by cheddarGoblin »
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #106 on: August 09, 2022, 06:00:59 PM »
I am still fighting an issue where the engine seems to bog around 5000 rpm but ONLY when I am on the highway. It does not do this in the lower gears or when in neutral.

So the next few posts are me trying to determine what is going on there.

I did rebuild the top end, I thought that I was careful installing the cam chain tensioner but to be sure, I dropped the oil pan to check. It didn't seem like it was the cam chain tensioner as I thought it was holding tension but I did not doubt my ability to mess something up.

The sump fell out while I was letting it drain.


Probably clean this out



Plus this needs a seal, so I can stop some oil leaks while I am at it.


Looks like it is in the right spot to me.


Guess I will keep looking
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #107 on: August 09, 2022, 06:37:21 PM »
I was pretty stumped as to what to look at next. I have checked and rechecked the carbs and cant find an issue there. Plus I think if it was a card problem, I would see the problem all the time, not just at highway speed.

I have checked cam chain tension and the proper placement of the tensioner.

I have replaced the chain and checked tension.

I have replaced the plugs, coils, and checked the ignition advance.

Then, one day I returned from a ride and shut the bike off inadvertently. I tried to start it again and the starter did not engage. I checked the voltage and:


I had heard of charging issues with these but mine had seemed to be working. But I also kept it on a tender at home. So now I am wondering if my problem is related to the charging system.

I checked the brushes and thought they were not to the service limit, I replaced them anyway



Once I got the battery charged up, I checked the charging when the bike wsa running at it seems ok at first glance


I also checked to rotor and it seems fine while not running.


So I checked the resistance of the field coil while running. I did not expect the resistance to change this much. Can anyone tell me if this looks right?


It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline RAFster122s

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Re: My accidental 1982 Nighthawk 650
« Reply #108 on: August 09, 2022, 06:44:25 PM »
Look at your wiring and run some resistance checks between the stator connections and their next point in the wiring. Black wire rot sometimes happens causing issues that stump the chump...
Not always just dodgy connectors. Black wire rot can happen in middle of wire that appears fine externally.
David- back in the desert SW!

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #109 on: August 09, 2022, 06:46:15 PM »
The rotor sliprings were pretty grimy, I figured that could not be a good thing so I cleaned them up to see if it would help.




I dont think anything has helped yet but still not sure if this is the issue.
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #110 on: August 09, 2022, 06:52:53 PM »
More detailed pics of the brushes.

They were not too worn but do the easy stuff first...right?








So that's done at least :)



It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #111 on: August 09, 2022, 06:56:04 PM »
In other news, while I was in the area I had noticed that the shifter shaft seemed to have a good leak.

I found that an AR bolt carrier is juuuuust long enough to drive the seal in.



Just take the bolt out before applying hammer!
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #112 on: August 09, 2022, 06:58:46 PM »
Look at your wiring and run some resistance checks between the stator connections and their next point in the wiring. Black wire rot sometimes happens causing issues that stump the chump...
Not always just dodgy connectors. Black wire rot can happen in middle of wire that appears fine externally.

I can certainly check that. I guess they should all just have similar resistance.
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #113 on: August 10, 2022, 08:08:35 AM »
I temporarily installed a voltage meter to see what it it doing while riding. Deepest apologies for the orientation.


It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #114 on: November 12, 2022, 05:58:07 PM »
I have been continuing to try to find the cause of the issue with the bike stalling past 5k rpm. While rechecking valve clearance, I realized that I wanted to re-torque the head bolts after a few heat cycles (there has been more than a few). So I did that while I was in there.

While putting the rocker box back on, I got a little carried away with my new electric ratchet....




But if you have the tools and parts to fix a boo boo, did it ever really happen?





I got the helicoil in and was MUCH more careful reinstalling the rocker box
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #115 on: November 12, 2022, 06:02:03 PM »
While checking the header bolts, I realized that I had probably overtorqued this one at some point.

Lucky for me, it is easily accessible and the same size helicoil, so I got it fixed right up.



It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #116 on: November 12, 2022, 06:10:59 PM »
EUREKA!

I finally got this thing running strong above 5k rpm!

It was as simple as removing the air box cover! As soon as I did that and took it for a ride, it ran fantastic. All hesitation was gone and it revved easily.

Clearly, this part is not letting in enough air.


What I don't understand is why? The carbs have stock 118 fast jets and it has the original airbox. This bike has 50k miles on it, I don't see how it could have gotten that much running terribly.
Could it be something to do with modern gasoline compared to gas 40 years ago?

This whole time I thought it was something that I missed with the carbs, or ignition related, or the drivetrain since I only noticed it in 4th or 5th gears and only under a load. I had even found other posts in different locations of people with the same bike describing the same symptoms but never with a posted solution.

Anybody got any ideas? 
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline Alan F.

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Re: My accidental 1982 Nighthawk 650
« Reply #117 on: November 12, 2022, 08:46:55 PM »
Good work, enjoy.
And know that you didn't miss anything.

Offline scunny

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Re: My accidental 1982 Nighthawk 650
« Reply #118 on: November 12, 2022, 09:02:04 PM »
going from memory some of the 650's ran better with the air box cover removed.
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Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #119 on: December 03, 2022, 09:13:44 AM »
Problem solved. I still can't believe this fixed it but it definitely did.

It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #120 on: September 15, 2024, 05:02:58 AM »
The bike has been great after allowing it to get more air. I still am surprised at how well it runs after doing that.

It was spitting oil everywhere. It ended up being the oil pressure switch itself that was leaking, at the top, near the electrical connection, not where the switch threads in.

So replacing it fixed the oil leak, New switch looks a little different but works fine.




« Last Edit: September 15, 2024, 10:18:52 AM by cheddarGoblin »
It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Offline cheddarGoblin

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Re: My accidental 1982 Nighthawk 650
« Reply #121 on: September 15, 2024, 05:29:19 AM »
I am calling this project complete. I learned a ton working on it and am happy with how it turned out!

I will not be in a hurry to take on another project that is so rough to begin with but this bike gave me something to do during COVID and is as old as I am so it will always be a special one to me.

It seemed like a good idea at the time

1975 CB200T
1982 Nighthawk 650
1981 GL500
1971 CB500
1972 CL350

Online Stev-o

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Re: My accidental 1982 Nighthawk 650
« Reply #122 on: September 16, 2024, 08:28:25 AM »
Great job!  Nominating you for BOTM....once seconded, plz go here to accept.

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Offline GRAND INQUISITOR

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Re: My accidental 1982 Nighthawk 650
« Reply #123 on: October 13, 2024, 09:02:37 AM »
Loving that air box mod, might do that on mine. Right now the previous owner had cracked it on the seams that I want to repair with JB weld because water could get in. Looks really cool, enjoy the ride-
1985 Honda CMX250 Rebel (Black)
1985 Honda CB650SC Nighthawk (Blue)