Author Topic: fun with my 84 Nighthawk  (Read 3400 times)

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #15 on: August 26, 2023, 08:03:10 PM »
have made a little progress on my Nighthawk..brake and clutch masters are cleaned, painted and I've replaced the sight glass in both. The old, yellow, crazed ones drove me nuts. Pretty easy to pop / pry out the old ones and put the new ones in using a 14 mm socket and a bench vise to gently push it in, straight.

I have my clutch slave cylinder disassembled and cleaned. Waiting on an additional oil seal and o ring that I wasn't aware of until I took it all apart.

Installed forks, front wheel and axle..torqued everything to spec. It finally looks like a bike, again.

Waiting on 2 new bleeders before I fully assemble my calipers. They have new seals in them and are cleaned up..almost ready to go.
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #16 on: August 26, 2023, 08:10:04 PM »
next steps are to rebuild brake master and assemble and install calipers, attach new stainless brake hoses (already loosely installed) and fill and bleed the system.

Then clutch master will be rebuilt along with clutch slave cylinder. Fill and bleed that system, too.

After that will be the pulling of the carbs to do a full rebuild on them, followed by a bench sync and a vacuum sync. Never done more than 1 carb before, but what the heck, I've never done any of this before! I'm finding out that it ain't rocket science. Mostly disassembling stuff, cleaning then replacing the rubber parts that wear out. Then reassemble!
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Stig / Major Tom

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Re: fun with my 84 Nighthawk
« Reply #17 on: August 26, 2023, 08:41:19 PM »
You're finding parts for this 39 yr old Honda?!

BTW - love the yellow accents! Brightens things up....on a Nightflyer!

Stig
Boston Strong
Rural Ohio

And, I'm feeling a little peculiar.

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #18 on: August 26, 2023, 08:59:50 PM »
yeah, surprisingly, all (or most) of the maintenance and wear items are still available..most OEM from Honda! Other big items would need to be purchased used (instrument cluster, headlight, seat, bars, those type things).

The fuel petcock is not available but rebuild kits are. I pull up parts schematics, just like we do with our scoots, to find the parts and then compare prices (and availability) between the different sellers.

There are a lot of aftermarket (reproduction) parts also available for the bike. It does share a lot of components with other Hondas from the era so I think that makes things easier to source.
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #19 on: August 27, 2023, 09:16:59 PM »
had a productive afternoon working on the bike...got both calipers fully rebuilt as well as the brake master cylinder. Everything went together surprisingly easily. It feels great to have clean, lubricated, properly functioning calipers, again, as well as a master that doesn't leak.

Loosely installed everything and hooked up the new stainless brake lines. Looking good! Tougher part will be filling the system with brake fluid and bleeding everything.

(EBC Double H sintered brake pads, same ones I have on my other bikes)
« Last Edit: August 27, 2023, 09:20:55 PM by Iahawk »
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #20 on: August 27, 2023, 09:19:05 PM »
and a few more pics of the calipers on the bike and the master....I know much of this probably seems pretty basic but it's the first time I've done really any of this and the sense of accomplishment feels great.
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #21 on: August 30, 2023, 02:01:30 AM »
more progress today...I'm starting to see the finish line..kind of...

installed 4 new NGK plugs..the old ones weren't too bad but I prefer to start new with all fluids and maintenance items. Went to attach the speedometer cable and overtightened the screw..snap!..a piece of plastic shot across the garage. I found it and superglued and then JB Welded the piece back on..not perfect, but good enough.

Finally pulled the clutch slave spacer (the part of the slave closest to the motor) and wow, what a crusty, rusty, disgusting oil seal that had. I pulled the rubber off and it was all metal underneath..corroded metal that had welded itself to the slave spacer. I soaked in penetrating oil and cooked with a propane torch a few times then was able to hammer in a small screwdriver into it to pry it out. I also replaced an o ring on the back side of that part. It appears the o ring was leaking oil from the clutch rod (looks like a car's pushrod).

Cleaned up, new seals, installed new seals and spring in the clutch slave cylinder then assembled it all together on the bike!
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #22 on: August 30, 2023, 02:18:24 AM »
also rebuilt clutch master with new parts plus new diaphragm, new cap screws and new crush washers for the banjo bolt. Greased the pivot points on the lever and realized I forgot to paint the end of the lever where it's been scratched...dang..

Transferred over the front brake hose clamps from the old brake lines to the new. These hold the front brake hoses and attach to the fork with 2 bolts. The old rubber hoses were fatter than the new stainless ones so I had to cut down the rubber grommet and squeeze the metal holder tighter on the new brake lines.

 Used some Back to Black on both plastic switchgear housings with surprisingly good results and installed the mirrors.

Tomorrow I hope to fill and bleed both brake and clutch systems..wish me luck.

next up - carb rebuild, petcock rebuild and gas tank clean and de-rust. Then fire her up!!
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #23 on: August 31, 2023, 11:13:50 PM »
continuing to make progress..filled and bled the hydraulic clutch system and brake system...after some additional tightening of the banjo bolts it went very well and was actually quite easy to get the system filled and bled (contrary to many horror stories I'd read about people trying to fill new systems).

used DA polisher with compound and polish then ceramic top coat on front fender..installed fender. Front end is all rebuilt and reassembled.

Fender's paint is not going to be perfect due to years of sun exposure and some 'alligatoring' in the finish..but it looks nice from 10 feet away.

received petcock rebuild kit in mail today so have most everything I need to continue on...carb removal and rebuild is next up. I'll go to the extra trouble of rear wheel removal in order to unhook and pull airbox backward, giving me much better access to carbs for removal.
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #24 on: September 03, 2023, 10:35:34 PM »
continuing to make progress...I reassembled the bike yesterday to show to a friend who was in town for the home football weekend here in Iowa City..

then stripped it down again, today. Removed rear wheel, rear fender, airbox (and all connections, both electrical and vacuum)..taking notes and taking plenty of pictures to document...plus following along exactly in service manuals..

This gave me the chance to clean the 'you know what' out of the bike..40 years of dirt and oily grime...man that feels good.

Didn't break anything during disassembly, luckily. Then it was simple to pull the bank of carbs off, using a little additional leverage from a prybar and block of wood. Started to strip down the carbs for cleaning and rebuilding. Everything looks very clean..cleaner than I would have expected. someone has been in the carbs before, they've been split, I can tell from the boogered up screws.

Done for the day...will start up on carbs again in the morning. Happy riding to all.
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #25 on: September 05, 2023, 09:51:11 PM »
still plugging away...cleaned up and painted the rusty battery tray and discovered the rubber air tubes going from the airbox to the carbs were not seated properly into the hard plastic airbox, letting unfiltered air into cylinders 1 and 2. It probably happened last time someone removed the carbs and jammed them back in. I'm very glad I removed the airbox to simplify carb removal.
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #26 on: September 05, 2023, 10:05:11 PM »
carbs are now completely cleaned..every passage, orifice, opening..soaked in Chem Dip, sprayed out with carb and brake cleaner and blown out with compressed air. I also used steel wool to polish up many parts like the inside of the emulsion tubes, the seat for the needle, choke plungesrs...everything! Resprayed every opening with brake cleaner and blasted with compressed air again this morning. They are set aside waiting to be put back together.

 I discovered someone installed #125 main jets in the bike (OEM is #115). Even with a K&N in the factory airbox that is way over jetted. After some research I've settled on 120 mains. Waiting on the new jets to be delivered before buttoning up the carbs.

Separating a bank of 4 carbs is also a very simple, straightforward process. Nothing like the nightmare you read about. I'm glad I did it as it gave me a chance to go through everything on the carbs.

I also cleaned up both 40 year old shocks with 0000 steel wool, replaced all 4 rubber shock bushings and touched up all the chips and nicks on the frame with a rust converter and then gloss black Rustoleum, brushed on. Surprisingly good match to the factory frame paint. Couldn't stand looking at rust spots on the frame!
« Last Edit: September 05, 2023, 10:08:30 PM by Iahawk »
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk
« Reply #27 on: September 19, 2023, 03:50:10 AM »
after what seemed like an eternity waiting for 4 new floats...they arrived yesterday! I started to install them and realized that the new floats were really no different, height wise, than the old floats. I took better measurements of the old ones..factory service manual calls for 18.5 mm plus or minus 1 mm. All 4 were slightly lower than the 18.5 mm but all were within the 1 mm tolerance..with 3 of the 4 at 19 mm and 1 just under 19.5. So I get to return the floats and spend the money on a carb sync tool, instead!

Reassembled the bank of 4 carbs and installed throttle cables and choke cable then installed on motor. So much easier without the airbox in the way. Used a heat gun to heat up the rubber intakes and added a little motor oil to them..took a little persuasion but they are all seated correctly.

Heading out of town for a few days but hope to get most of the bike reassembled this weekend. Getting the carbs reassembled and installed was a big step forward.
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Iahawk

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Re: fun with my 84 Nighthawk - it's alive!
« Reply #28 on: September 24, 2023, 08:14:51 PM »
well, to wrap up this story (for now)..I got the cleaned carbs back on the bike, put airbox on (attaching airbox boots to carbs was a pain..airbox rubbers have shrunk about 1/4 inch over time..used heat and force and stronger clamps to keep them in place)..rear fender, wheel, brake rod, tail, seat, battery and side covers installed..

filled carbs up with fuel using a ketchup squeeze bottle filled with fuel, through the fuel line,  before installing tank as I wanted to check for leaks from the many places they could leak...no leaks! Rebuilt petcock this morning..no leaks there (for now)..drained tank and refilled with zero ethanol premium and fuel stabilizer...

Installed tank and she fired up! It took a bit of trying and fiddling with the manual choke..but she fired up and I took her on her maiden voyage..about 32 miles around town. What a comfortable, smooth ride.

I especially love the 'closed throttle' response of the motor...very smooth with no jerking when throttle is closed, unlike my fuel injected Ninja...which goes from about 20% throttle to 0%..nothing in between..and it will jerk and throw you forward a bit if you're not practicing perfect throttle control. Leaner fueling for emissions compliance, as I understand it.

So still need new tires (old ones are date coded 2011) and the valve cover gasket and rubber cam end caps leak so those will need to be replaced..and I need to sync the carbs with a real syncing tool...I did the old 'eyeball sync' when they were off the bike! Got 'em close but they still need a real syncing.
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

Neil955i

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Re: fun with my 84 Nighthawk
« Reply #29 on: September 25, 2023, 08:22:35 AM »
Cracking job Hawk, you can be justifiably proud of your work!
Regards & ride safe,
Neil

Current garage:  Kymco DTX360 & Triumph Street Triple 675R
Past bikes: BSA C15. Honda S/wing (GL500). Kawasaki GPz750. BMW K100RS. Kawasaki GPZ900R. Yamaha FJ1200 x2. Sprint. Triumph Daytona 900. Kawasaki ZX-7R. T595 Daytona. Kawasaki ZX-9R x2. Triumph Daytona 955i. X-Town

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