Topic: 1980 CB750 Custom DOHC

[enforcer]

Hey Guys:

I've been thinking about getting a second bike to compliment my K5 cafe.  There is a 1980 CB750 Custom for sale in my town.  I talked to the owner, but have not seen it yet. 
Here is a rundown:  everything original, no accessories, 28,000 miles, no dents or scratches on gas tank or side covers, seat is ripped, chain and sprokets replaced recently, all electrical parts work, runs good, looks good.  Asking price $900.

I am looking for input.  I'm not real familiar with the DOHC models.  Does anyone own one?  How is there reliability, driveability, etc... compared to the the earlier SOHC models such as my K5?  What do you think of the asking price?

Thanks,
Enforcer

[nickjtc]

You're gaining a tad more power, more weight and more complexity. Spares availability shouldn't be better or worse than for sohc's.

[enforcer]

Thanks for your reply.  What makes it more complex besides the DOHC vs the SOHC?  Are there other major differences besides the DOHC and appearance?

[nickjtc]

Thanks for your reply.  What makes it more complex besides the DOHC vs the SOHC?  Are there other major differences besides the DOHC and appearance?

Just that fact that it is dohc.

[Rocking-M]

I did have one for a short time and it seemed reliable to me then.
It had about 20k on it. Do all the adjustments if you get it,
valves, t-chain, etc... and she should run a while yet for you.

[bill440cars]

          I don't think you'll be sorry. I've got an 80' 750K and it's a pretty good runner. Picked mine up real cheap. some parts will interchange between the 750 and the 900 for sure and I think somewhat with the 1000 also. I'd have to do some serious research to say what will fit both the 750 and the 900.
I know there's a site for the DOHC "C" and one for the "F" but, alas, not one for the "K". The site for the "F" doesn't want any reference made about anything but the "F". Not sure about the site for the "C". I'll try to find the site for you just in case you or anyone else hasn't yet. Later on, Bill

[eldar]

I would like that bike too. Supposedly, the dohc engines were not as bulletproof, supposedly. That could just be talk from people in love with the sohc though.

I think you are also able to put on the later year brakes which are 2 puckers. Much better brakes than the sohc singles.

Maybe not quite as much for parts but I dont know, check ebay just for reference.

I would see the bike though before plunking down 900. I suppose that goes without saying!

[74cb750]

I had the 1979 DOHC 10th anniversay edition.
Won't say how much I sold it for as it is embarassingly low,
major problems after it sold,
electrics melted after 15,000 miles. Messed up lots of stuff,
coils, heat sink, CDI etc etc.
I was not impressed as the PO kept coming back wanting me to
fix it for free
Maybe you'll have better luck.
peace,
michel

[scunny]

a friend of mine has one, every few months he charges the battery, goes for a ride, comes home parks it and expects it to go well the next time.
maintenance.... nil.......he probably can't even spell it. seems to be reliable to me.( he has owned it for a long time now)

[putnaja1]

a friend of mine has one, every few months he charges the battery, goes for a ride, comes home parks it and expects it to go well the next time.
maintenance.... nil.......he probably can't even spell it. seems to be reliable to me.( he has owned it for a long time now)

I had a '79 750F, an '81 750F, and an '82 900F.  The 900F was by far the best- two piston pots, triple discs.

All the DOHC had electronic ignition.  I'm not sure why, but after the later SOHC4 went to a recessed gas cap under a door, the DOHC CBs went back to an external gas cap.  The 900F had a stock oil cooler and reservoir rear shocks.  The early DOHCs had air adjust forks- but I think they were done away with in favor of traditional forks later on.  There is a compartment for the tool kit, under the airbox which is kinda neat.

The '79 models (at least the 750F I know certainly had this problem) had charging problems- I can't remember all the details now, but I think they would keep burning up the stator coils.  I had one that wouldn't charge, and had to replace the stator twice.  Finally, I found out about a technical service bulleton Honda had about the problem, and there is a fix kit that Honda sold that had a plug in replacement charging harness- unplug the old, plug in the new, hook it up, and as long as the parts in your charging system are still good, charging problems were solved.   

[Jay B]

I've got a 10th Anniversary edition coming up as a project bike. 20k miles, it is absolutely pristine except for exhaust and the fact that it hasn't been started in 18 years. I've heard of exhaust valve issues with the dohc's, but nothing I can confirm.

[YogiBear]

          I don't think you'll be sorry. I've got an 80' 750K and it's a pretty good runner. Picked mine up real cheap. some parts will interchange between the 750 and the 900 for sure and I think somewhat with the 1000 also. I'd have to do some serious research to say what will fit both the 750 and the 900.
I know there's a site for the DOHC "C" and one for the "F" but, alas, not one for the "K". The site for the "F" doesn't want any reference made about anything but the "F". Not sure about the site for the "C". I'll try to find the site for you just in case you or anyone else hasn't yet. Later on, Bill

CB750C.com is a forum for The K,F, and C. They just focus on the Customs, but alot of guys on there have K models as well and alot of the guys have good tech info for the K models too.

[tramp]

as a rule of thumb the older dohc take more care to maintain
deliver a little more power
take care of them and they'll last a long time