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

[slmjim n Z1BEBE_imp]

Many of us have (or have had) late model CB750 Nighthawks. This is a long post re: the mental gymnastics we're going through regarding our consideration of changing up our Ridin' stable. It does include thoughts about acquisition of a CB1100EX.

Thinking cap suggested.

We're on multiple fences re: keeping our His n Her pair of '93 Nighthawks we bought new. Recent pic:


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 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 prob
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 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.
Upsides - 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.

Downsides - 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. On this forum, this applies especially to the CB1100EX bike under consideration.

Crossposted to a couple other forums.

Good Ridin'
slmjim & Z1BEBE

[GoldOxide_imp]

Not sure if this is helpful, but here goes ...

I owned an '84 Nighthawk CB750S and wished I never sold it.

Was it perfect? No.
Was it near perfect and cool (for me)? Yes.
Is it collectible today? You bet.
Was it sentimental? Yes. I miss the darn thing.

= = =

I owned a '14 CB1100 and eventually sold it.

Does it have a crappy final chain drive? Yes.
Was it perfect? No.
Was it near perfect and cool (for me)? Yes.
Is it collectible today? Perhaps.
Was it sentimental? It was.
Was it better than the '84 CB750S? Yes.

= = =

The innate feeling, power, quality, low cost of ownership and Forum support would make me pick the CB1100 (even with final chain drive) over the CB750S. That wasn't easy to type down.

As always promised to any rider, it will be the last bike you will ever need to own.

Good luck on your ultimate choices.

[Gone in 60]

That’s a lot to unpack. I put many happy commuting miles on my ‘93 Nighthawk and it was dead reliable. Sold it to a friend who put even more miles on it than I did and it’s probably still alive somewhere.

To me, the CB1100 riding experience is like a bigger more powerful Nighthawk.

The Nighthawk’s self-adjusting valves are very nice. And they are the Honda Civic of the motorcycle world. You pointed out the tach, which was a weak point due to impossible-to-reach-and-repair solder joints. Mainly, I would be concerned about the availability of rubber bits like gaskets and bushings. Also, they have a lot of hard plastic bodywork that is now very brittle, will only get more so, and will not be replaceable.

I didn’t have the sentimental bond to mine that you do, but I’d have a hard time wanting to work hard to keep a bike like that in pristine shape if I was going to continue putting miles on it.

[GoldOxide_imp]

Store the other bikes outside?

It does happen.

[Cormanus]

I feel for you, slmjim & Z1BEBE. Your decision is almost entirely an emotional one. If, like Mr Spock, you simply applied logic, you'd cull the collection heavily and buy a single modern bike that will meet your needs for local riding and the occasional 2-up tour. But you're not going to do that because the Z1 collection is there to stay. Seems to me the prospect of parting with one or both of the Nighthawks causes you to wake in the middle of the night with faces wet with tears.

Perhaps the best thing to do is nothing. Time will force your hand. The ST1300 is a hefty beast and will come a time when managing the weight is too much. That will provide a decision point. Likewise, the non-pickled Nighthawk may break a 'high mortality' part which makes it clear that keeping it on the road has become too much trouble. By then circumstances will have changed: for example, the ST1300 may also have become to heavy or is not being used enough; or it's clear that a smaller, lighter bike like a 2023 CB750 Hornet is a better option, etc.

However, if you really, really, really feel the need to act now, why not sell one Nighthawk and replace it with the CB1100 as a your high usage bike. I'd think hard about that option as, although not as porky as the ST1300, the CB1100 isn't light and your concern about weight may end up being realised twice in quicker succession than you expected. And that's not to mention spoked wheels and the irritation of trying to find 18" tyres.

Doing nothing seems a good option to me.

Best of luck with your thinking.

[Ollie]

I'll offer my thoughts. Back in 2015 I rode my 2000 CB750 Nighthawk (with around 14,000 miles) to the dealer with the intention of trading for a 2014 CB1100 they had on the floor. However when I sat on the CB1100 it was less roomy and comfortable than my Nighthawk (which did have a great Corbin seat). On the stock CB1100 the bump in the seat positioned me too close to the tank which further aggravated the slightly higher foot pegs. Then there was also the occasional valve adjustments to factor in.
However it did have more power and torque, better brakes, FI (which I far prefer over carbs), 6-speed with a nice tall 6th gear, to my eye better looks, and 14 years newer everything. But after factoring in everything I decided to hold off trading.

I continued riding the Nighthawk but often wished for just a bit more torque. Also the bike always used oil, not a lot but it'd not reach 3,000 miles (when I changed oil) without having to add some more Mobil 1 4T to move it off the add line, which bothered me. Eventually I simply became bored and sold it. But I missed having an air cooled in-line 4 cylinder motorcycle. I didn't want to go too old though and kept thinking about the CB1100.

Forward to 2021 I saw a used 2014 CB1100 with only 2K and ended up buying it. I had Corbin make a seat that both raised and moved me slightly back which made a huge improvement for my 32" legs. Also added a quick release National Cycle shield, Honda luggage rack and center stand, and soft throw over panniers. It's just a nice versatile UJM with plenty of power which is exactly what I wanted. I usually ride the bike naked (the bike not me!) but for longer rides I just add the shield and soft bags, and off we go. I love this motorcycle and as set up is just a nicer, more fun bike to ride (at least for me) than the 750 Nighthawk was.

[slmjim n Z1BEBE_imp]

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 subjective responses everyone.

Good Ridin'
slmjim & Z1BEBE

[pdedse]

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 subjective responses everyone.

Good Ridin'
slmjim & Z1BEBE

Aging gracefully, it sounds.

"N + 1"...I haven't heard that term used in a long time. May I ask in what context you're familiar with it? I thought it was specific to language teaching/learning theory, but internet shows me some other "applications" of the term.

[GoldOxide_imp]

[pdedse]

Whatever that was Gold,... what is it?