'91 - '03 750 Nighthawk longevity & high mortality parts? Other thoughts. Long.

[slmjim n Z1BEBE]

Long post to follow. Thinking cap suggested.

We're on multiple fences re: keeping our His n Her pair of '93 Nighthawks we bought new.  Both have 70,000+ relatively trouble free, adult touring miles on them.  We never wailed on them & they're always garaged.  Very well maintained by us. We're Kawasaki Z1 collectors & restoration hobbyists with 40-+ yrs. experience.

We're both over 70.  The Lovely Z1BEBE decided to hang up her keys last year, so I pickled her red '93 Nighthawk for long-term storage.  My blue '93 Nighthawk needed the carb diaphragms replaced this year, as one was holed.  A cheap rack of very-low-mile 750 Nighthawk carbs from fleabay solved that.

I'll continue Ridin';  Joyrides solo on my 750 when the spirit moves me, and Z1BEBE is happy doing the passenger thing on our ST1300A, with a rarel two-up on my Nighthawk, although we'd both like a top box w/ backrest for her.

So, we have two '93 'Hawks, I'm in the autumn of my Ridin' career, and I don't know how many more years I'll be Ridin'.  My Ridin' will be split between my Nighthawk, the ST1300A, and whichever of our Kawasaki Z1's we prep for a given season.

Caveat - we're out of room.  Garage is full with two vehicles and three bikes, lawn care equipment, and a Honda Hobbit PA50-II moped. The basement shop has six bikes in it. Another one cannot be squeezed into the shop without completely blocking the bike service area.  One more bike isn't gonna happen anywhere here at home.

In all cases mentioned below, we keep our collection of Kawasaki Z1's.


Fence 1 - Keep both Nighthawks & prep one alternately each year for maybe, maybe, 2,500 mi. per season.  Likely less.  This bring up the question of longevity.  The CB750 motor is one of the most robust ever manufactured.  But, like any machine, there are certain 'high mortality' parts within. "High mortality' is not to be confused with consumable hardware such as spark plugs, chains/sprockets, wheel bearings, brake pads, cables & such.

   Upside - We know the model well, know the exact 70,000+ mi. history of our bikes, and have experience, + all the docs & most spares we're likely to need.

   We have irrational sentimental attachment for our Nighthawks.  We've spent 30 yrs. of our 34 years marriage & 70,000 mi. all over two-lane America  on them.  They mean something to us.

   Cost - essentially nil.

   Cheap to insure.

   Reasonably deep interwebs knowledge base.

   Downside - 70,000+ mi.  Brings up the longevity Q1 & Q2 questions below.

   Not easy to set up for comfy passenger two-up Ridin' + storage due to most accessories NLA.

Q1) We see anecdotal evidence the CB750 Nighthawk motor typically runs trouble-free for 100,000 mi. with good care & maintenance.  What sat ye about longevity? Is 100,000 mi. a reasonable estimate based on history of this motor's design?

Q2) What are the (relatively) high-mortality parts in the '91 - '03 750 motor, or the bike in general?  Our list so far is:

   Turn signals (stalks breaking).

   Switchgear, particularly the start switch itself becoming intermittent in the 'RUN' position re: the headlight not always coming on after the motor starts.  May be NLA.

   Tach.  Won't break the bike, but aggravating.  Later tachs seem to have solved the problem.  We have a late NOS tach on the shelf just in case.

   Valve cover gaskets. We replaced both @ ~50,000 mi. or so due to slow weeping developing.  Easy.

   O-rings at the fuel 'T' & junction pipes.  Easy.

   Petcock - one failed years ago.  Leaked in the 'OFF' position & motor went into hydraulic lock.  Rebuild kit failed.  Replaced with new OEM.  Not exactly high-mortality, but still...

That's about it for our high-mortality list.  Any suggestions, parts we've missed?


From here down we're mostly talking to ourselves. It just helps to see things in print sometimes for thoughts to jell.  We're most interested in the above.  Feel free though, to chime in on how you've managed similar considerations.


Fence 2)  Sell both our 750's & replace with one, nice, much-lower-mileage '91 - '03 Nighthawk.  They're out there.

  Upside - much newer bike we're very familiar with, & have experience + the service manuals & some spares on the shelf.

  Still cheap to insure.

  Downside - We have irrational sentimental attachment for our Nighthawks.  We've spent 30 yrs. of our 34 years marriage & 70,000 mi. all over two-lane America  on them.

  Unknown history.

  Not easy to set up for comfy passenger two-up Ridin' + storage due to most accessories NLA.

  Cost.


Fence 3)  An friend & fellow vintage bike resto hobbyist has a one-owner, low-mile (800 mi. !) 2017 CB1100EX for sale.  We sell both 'Hawks, replace them w/ the CB1100 set up w/ top box/backrest.

   Upside - Much newer bike. Current OEM parts support. More power than any 750.

   Can easily be set up with a top box using currently-available rack & box for backrest & storage for short two-up day / weekend Ridin'.

   Known history of this CB1100.

   Reasonably deep interwebs knowledge base.

   Downside -  We start from scratch on parts stock, documentation and a learning curve of a different, much more complex (ABS, fuel injected) bike.

   Spoke wheels (tubes) & uncommon tire sizes.

   Also, irrational 'Hawk attachment & etc.

   More expensive to insure.

   Cost++


Fence 4)  Realistically, how many more 3+ week, 2,000+ mi. tours are we likely to do on the ST1300A?  The older I get, the taller & heavier it gets.  It's a top heavy beast even without a passenger.  Her natural parts & single bionic part are making themselves more & more known after a few hours in the saddle.  Only stamina issues (so far) I have is typical numbbutt.

Sell the 'Hawks and the ST.  Set the CB1100 up w/top box for day / weekend trips.

   Upsides & downsides - same as Fence 3.  Insurance increase becomes a wash due to fewer bikes.


That's enough for now.  The main focus is the longevity considerations & suggestions.  Further thoughts welcomed for the talking-to-ourselves portion if the spirit so moves you.


Crossposted to a couple other forums.


Good Ridin'
slmjim & Z1BEBE

[Bob H]

We're both over 70.
Sell the 'Hawks and the ST.  Set the CB1100 up w/top box for day / weekend trips.

I am 67 and starting to notice that I am getting weaker. Starting to work out to counteract that - but I am glad my '93 NH 750 doesn't have the weight of your ST or the CB 1100 you are considering.

The CB750 motor is one of the most robust ever manufactured.
...We have irrational sentimental attachment for our Nighthawks.  We've spent 30 yrs. of our 34 years marriage & 70,000 mi. all over two-lane America  on them.  They mean something to us.

There was a guy on previous Nighthawk forum (Loki) who had over 100,000 on his and was known to ride it very hard. With hydraulic valve adjustment, these bikes are pretty bulletproof. But you can't leave fuel in the float bowls and let it sit very long. I used to drain my bowls if I got called to work out of town.
Even 10 days sitting will make my bike hard to start despite priming the carbs and having just replaced all carb components, ultrasonic, etc. Runs PERFECT once started. But something with dry passageways, my bike takes a lot of cranking if it hasn't been run within 10 days.

Turn signals (stalks breaking).

Yeah, I like the stock signal lenses because they are BIG and visible to other vehicles when I put superbright LED bulbs in them. But the stalks are crap, like rubberized garbage.

There are a bunch of knockoffs you will see on Ebay lately that are an exact copy. The stems look the same but are not rubberized. The inner reflector is matt silver rather than polished mirror finish, but with bright bulbs they are fine.

The top one is the $23 Ebay part, they have 2 wire or 3 wire depending on rear or front.
https://www.ebay.com/itm/141940542471

[mollusc]

As mentioned, Loki was a hard rider and went to over 100k on his CB750; I've seen reports of a few others going over 120k.
Not too sure about the CB1100.  It wasn't around all that long and while the platform looked appealing to many, I'm not really sure why it didn't find much of a market.  The relatively short life might make it a bit of a hassle to find parts or aftermarket accessories.
EFI is not a thing that you really need to learn about.  Really, either it works or it doesn't.  I have no trouble at all jumping between my Nighthawk (when it's running) and my NC700.
I had ABS on my BMW.  Didn't really pay any mind to it, but I didn't ride that bike much and never "got into it" so I didn't develop any different braking habits.  Supposedly there are ways that you can adjust your brake use to ensure as short a stopping distance with ABS as without (I think FortNine has a Youtube video about this).

[Pete in PA]

Wow. A lot to think about.

Only thing I know is the tach. thing never got fixed or improved.

Checked out several used 01-03 NH,s with inop tachs.

I'm only 59 and downsized to less and smaller bikes.  My 92 is my only bike now. 

[Bob H]

Tach.  Won't break the bike, but aggravating. 
...We have a late NOS tach on the shelf just in case.

Having a brand new - old stock tach. Amazing preparation.

[draser]

So, we have two '93 'Hawks, I'm in the autumn of my Ridin' career, and I don't know how many more years I'll be Ridin'.  My Ridin' will be split between my Nighthawk, the ST1300A, and whichever of our Kawasaki Z1's we prep for a given season.

Caveat - we're out of room.  Garage is full with two vehicles and three bikes

I can relate to that, as I have one 97 NH and two Magnas (82 and 84 model) in the garage right now (along with an 84 Magna parts bike and an 84 Shadow in process of restoration), and usually split my riding between the NH and one of the Magnas.

Longevity and parts - well, I had the Magnas going on 7 yrs now, and ridden one of them for the last 6 yrs. My rides were 400-600 miles/day local rides and the bikes behaved pretty good (with up-to-date maintenance of course) and never had an issue.

The Magnas, being older, the only issue I had was an oil leak out of the cross shaft assembly, when I removed and resealed the assembly. The leak was minimal and only at higher speeds, so nothing unusual there. The parts were available at both Partzilla/Carolina Cycle distributors, but I use the online OringStore to get my o-rings due to better prices, higher selection and better materials.

The tach on the 82 Magna was dead on arrival so I purchased a set (odo and tach) off of ebay, I also replaced the original odometer (85 mph) with an 84 model one (140 mph) - kept the original for my records (bike only had 6k miles when bought). Still have the original tach for a (future) repair on a rainy day.

The turn signal stems - had to replace several of them however they are available multiple places now.

The radiator hoses - available on ebay, replaced all with silicone type. In general I tried to replace all rubber due to age deterioration.

I should have pointed out that, this bike underwent a general restoration of all safety systems, therefore I didn't have nor expected failures of brakes, suspension, tires, etc. So life was good on the Magna side.

My 97 Nighthawk, being newer and in perfect condition when bought, never had an issue - other than replacing the rear right turn signal stem, now needing the left one. No oil leaks or any problems of any kind. I overhauled the carbs as regular maintenance for a bike new to me, with all o-rings from the OringStore. Beautiful bike, don't like the clunky shifter though.

However, things were a lot different with the Shadow, recent purchase at the end of this year, bought as a winter project. While I was able to ensure the engine was in good condition and ran fine (after a carb rebuild) I ran into problems quickly trying to procure the usual rubber/wear components (radiator hoses, caliper rubber boots, swing arm dust seals, etc.). The solution for me was to source the parts - using Partzilla part dimensions - from other suppliers available on the net, but being careful to get known good supplier parts and trying to stay away from cheap replacements. For the radiator hoses, since there's no kit available that I can find, I have to order from a catalog (I use Gates) and get hoses that match the dimensions and shape of the ones I have on the bike.

So, in summary, as an owner of older bikes, getting good replacement parts has challenges, but the reward is all the fine rides in summertime. Luckily, these Honda bikes have such good built in quality that, after the initial restoration/maintenance update, they seem to run like new.

Just like you, as the number of bikes grows, there's the question of which one to keep and what to sell. I am at this point now and there seems to be an attachment to some bikes more than others. I wish I had a larger garage and keep them all.

[slmjim n Z1BEBE]

Warm-ish day yesterday. Got out on my BlueHawk for 25 mi. or so, long enough to mix Stabil into the topped-off tank. Bike ran perfectly and reminded me (yet again) why we fell in love with the 'Hawks in the first place. Will drain the carbs today for winter. The Ride was also long enough to make me question (yet again); Why let go of our '93 'Hawks?
Anecdotal evidence & general consensus is CB750 Nighthawks can reasonably be counted on to reliably be 100K mile bikes, given good care & maintenance.

During our daily hour+ dog park excursion afterward, we discussed (again) what course of action to take. Z1BEBE sez she's happy to keep status quo. That's likely what we'll do. The impetus of stasis, of doing nothing, is strong.

With my future miles as Rider being split between whichever 'Hawk we prep for a Ridin' season, our ST1300A dedicated to two-up, and whichever Z1 we prep for joyrides, shows & charity runs that season, I'd be pushing 100 yrs. old by the time either 'Hawk got to 100K miles, and that only if one & not the other 'Hawk was ridden every year.

Used to be, the correct number of bikes to have is n+ 1. Aging changes that calculation for us.

Bottom line is, we're happy with what we've got. It was so obvious we couldn't see it.

Thanks for the relatively objective responses everyone.

Good Ridin'
slmjim & Z1BEBE

[Bob H]

I'd be pushing 100 yrs. old by the time either 'Hawk got to 100K miles, and that only if one & not the other 'Hawk was ridden every year.

We're both over 70.  The Lovely Z1BEBE decided to hang up her keys last year, so I pickled her red '93 Nighthawk for long-term storage.  My blue '93 Nighthawk needed the carb diaphragms replaced this year...

I'll continue Ridin'

I would sell ONE of them if she doesn't ride.
You collect vintage bikes, so you know that the best maintenance is to ride them.
Awesome you drain the carbs for winter.
But with time, soft rubber tires turn into hard wooden garbage. How do you maintain good tires on lots of bikes?

... Only stamina issues (so far) I have is typical numbbutt.

Do an internet search for "air motorcycle seat cushion" and you will find $30 knock-offs of the air hawk cushion.

If you put very little air in it, they evenly distribute pressure without feeling like you are rolling around on it.

The key is to only put enough air so 2 hands are supported when you press down, but one hand will bottom out. The 2 hands will be like your ass, and will float just over the surface of your seat. The human body gets bony sore points where the "sit bones" are located. The cheap pad eliminates that.

https://imgur.com/oc5sBSP

[Steppin Razor]

Don't know if you made the decision, but I'd suggest either option 4, or 4 minus buying the CB1100.  You're Kawasaki collectors, with a desire to continue that above all else, and have a few (?) to continue riding until you hang up the keys.

Nighthawks have given you good service, the experiences and the memories aren't stored in the bikes, so I'd say let them retire/bring someone else adventures. 

[clearviewx]

Long post to follow. Thinking cap suggested.

We're on multiple fences re: keeping our His n Her pair of '93 Nighthawks we bought new.  Both have 70,000+ relatively trouble free, adult touring miles on them.  We never wailed on them & they're always garaged.  Very well maintained by us. We're Kawasaki Z1 collectors & restoration hobbyists with 40-+ yrs. experience.

We're both over 70.  The Lovely Z1BEBE decided to hang up her keys last year, so I pickled her red '93 Nighthawk for long-term storage.  My blue '93 Nighthawk needed the carb diaphragms replaced this year, as one was holed.  A cheap rack of very-low-mile 750 Nighthawk carbs from fleabay solved that.

I'll continue Ridin';  Joyrides solo on my 750 when the spirit moves me, and Z1BEBE is happy doing the passenger thing on our ST1300A, with a rarel two-up on my Nighthawk, although we'd both like a top box w/ backrest for her.

So, we have two '93 'Hawks, I'm in the autumn of my Ridin' career, and I don't know how many more years I'll be Ridin'.  My Ridin' will be split between my Nighthawk, the ST1300A, and whichever of our Kawasaki Z1's we prep for a given season.

Caveat - we're out of room.  Garage is full with two vehicles and three bikes, lawn care equipment, and a Honda Hobbit PA50-II moped. The basement shop has six bikes in it. Another one cannot be squeezed into the shop without completely blocking the bike service area.  One more bike isn't gonna happen anywhere here at home.

In all cases mentioned below, we keep our collection of Kawasaki Z1's.


Fence 1 - Keep both Nighthawks & prep one alternately each year for maybe, maybe, 2,500 mi. per season.  Likely less.  This bring up the question of longevity.  The CB750 motor is one of the most robust ever manufactured.  But, like any machine, there are certain 'high mortality' parts within. "High mortality' is not to be confused with consumable hardware such as spark plugs, chains/sprockets, wheel bearings, brake pads, cables & such.

   Upside - We know the model well, know the exact 70,000+ mi. history of our bikes, and have experience, + all the docs & most spares we're likely to need.

   We have irrational sentimental attachment for our Nighthawks.  We've spent 30 yrs. of our 34 years marriage & 70,000 mi. all over two-lane America  on them.  They mean something to us.

   Cost - essentially nil.

   Cheap to insure.

   Reasonably deep interwebs knowledge base.

   Downside - 70,000+ mi.  Brings up the longevity Q1 & Q2 questions below.

   Not easy to set up for comfy passenger two-up Ridin' + storage due to most accessories NLA.

Q1) We see anecdotal evidence the CB750 Nighthawk motor typically runs trouble-free for 100,000 mi. with good care & maintenance.  What sat ye about longevity? Is 100,000 mi. a reasonable estimate based on history of this motor's design?

Q2) What are the (relatively) high-mortality parts in the '91 - '03 750 motor, or the bike in general?  Our list so far is:

   Turn signals (stalks breaking).

   Switchgear, particularly the start switch itself becoming intermittent in the 'RUN' position re: the headlight not always coming on after the motor starts.  May be NLA.

   Tach.  Won't break the bike, but aggravating.  Later tachs seem to have solved the problem.  We have a late NOS tach on the shelf just in case.

   Valve cover gaskets. We replaced both @ ~50,000 mi. or so due to slow weeping developing.  Easy.

   O-rings at the fuel 'T' & junction pipes.  Easy.

   Petcock - one failed years ago.  Leaked in the 'OFF' position & motor went into hydraulic lock.  Rebuild kit failed.  Replaced with new OEM.  Not exactly high-mortality, but still...

That's about it for our high-mortality list.  Any suggestions, parts we've missed?


From here down we're mostly talking to ourselves. It just helps to see things in print sometimes for thoughts to jell.  We're most interested in the above.  Feel free though, to chime in on how you've managed similar considerations.


Fence 2)  Sell both our 750's & replace with one, nice, much-lower-mileage '91 - '03 Nighthawk.  They're out there.

  Upside - much newer bike we're very familiar with, & have experience + the service manuals & some spares on the shelf.

  Still cheap to insure.

  Downside - We have irrational sentimental attachment for our Nighthawks.  We've spent 30 yrs. of our 34 years marriage & 70,000 mi. all over two-lane America  on them.

  Unknown history.

  Not easy to set up for comfy passenger two-up Ridin' + storage due to most accessories NLA.

  Cost.


Fence 3)  An friend & fellow vintage bike resto hobbyist has a one-owner, low-mile (800 mi. !) 2017 CB1100EX for sale.  We sell both 'Hawks, replace them w/ the CB1100 set up w/ top box/backrest.

   Upside - Much newer bike. Current OEM parts support. More power than any 750.

   Can easily be set up with a top box using currently-available rack & box for backrest & storage for short two-up day / weekend Ridin'.

   Known history of this CB1100.

   Reasonably deep interwebs knowledge base.

   Downside -  We start from scratch on parts stock, documentation and a learning curve of a different, much more complex (ABS, fuel injected) bike.

   Spoke wheels (tubes) & uncommon tire sizes.

   Also, irrational 'Hawk attachment & etc.

   More expensive to insure.

   Cost++


Fence 4)  Realistically, how many more 3+ week, 2,000+ mi. tours are we likely to do on the ST1300A?  The older I get, the taller & heavier it gets.  It's a top heavy beast even without a passenger.  Her natural parts & single bionic part are making themselves more & more known after a few hours in the saddle.  Only stamina issues (so far) I have is typical numbbutt.

Sell the 'Hawks and the ST.  Set the CB1100 up w/top box for day / weekend trips.

   Upsides & downsides - same as Fence 3.  Insurance increase becomes a wash due to fewer bikes.


That's enough for now.  The main focus is the longevity considerations & suggestions.  Further thoughts welcomed for the talking-to-ourselves portion if the spirit so moves you.


Crossposted to a couple other forums.


Good Ridin'
slmjim & Z1BEBE

Go with the Fence 3.  I have a 2014 Honda CB1100 Deluxe.  No problems with it.