Topic: First year dohc CB750s; how do they rate?

[gregwaits]

A friend of mine has been fascinated with CB750s since he helped me pick up my '78K when I first bought it last summer.

He has an '07 Gold Wing, and I think he is tired of all that weight and all the rest that goes with a Wing. He loves that bike, but he wants something that is easier to push around and handle.

He is looking at a very clean '79 CB750 for $1,500. Are there any notable problems with those early dohc fours? I know that the dohc is quicker than the sohc, but reliability is my concern (for his sake anyway). I know that the sohc is more reliable than the dohc.

[Terry in Australia]

Well it's not so much that the SOHC bike is more reliable Greg, (everything below the cylinder head is of a similar design) the DOHC engines produced a fair whack more BHP than their SOHC parents, and so were more stressed.

The main problems (that I'm aware of, at least) were seized cam chain adjusters, (there were two adjusters from memory, one at the front and one at the back of the cylinder block) "weak" bottom ends, (plain bearing cranks like ours, and easily damaged if regular oil change intervals were ignored) and dodgy ignition modules.

They were still far more robust than the early VF750 and VF1000 V4 engines which were absolute dogs, it's amazing how Honda was able to build something as magnificent as the SOHC CB750, and then take 10 steps backwards with several models which all but destroyed the company's reputation for excellence in engineering.........

They certainly aren't as "collectible" as the earlier SOHC bikes, but if your mate has found one that's in good original cosmetic condition and looks like the engine's been looked after, (stay away from rattley engines that will need a top end rebuild) then he should buy it. Just make sure he gives it an oil and filter change as his first priority! Cheers, Terry.

[Jay B]

I've heard of heads cracking at the bridge between the exhaust valves, but not common. Having said that, I got a '79 up and running after sitting for 20 years for my brother. He bought it new. Runs like a top.

[okie]

I bought both a '79 and an '80 new and had absolutely NO problems with them.  They ran fast and flawlessly.  They were used as everyday commuter bikes and went 60 miles every day, rain or shine, hot or cold.  My only complaint about them was having to buy shims to adjust the valves.  It was a major PITA. 

[bill440cars]

       I've got an 80' CB750K that seems to be a pretty good runner. I'm still learning about the rest.   Good to hear some input about them. I was looking for a SOHC 750, when this deal came and couldn't resist.


                                   Later on, Bill

[gregwaits]

What? Bill bought another bike!? jk jk 

[nickjtc]

The only good Honda four in 1979 was the 650. 

[bryanj]

There was a mod to the oil bypass casting inside the engine that if not done meant the sprocket seal blew out dur to high pressure oil, if you PM me i will try and find the bulletin for you

[bill440cars]

What? Bill bought another bike!? jk jk 

                Good one!       Only thing is, I've had that one for a while now.   I did however, pickup a 79' CB750K (that someone stuck  a 3wheeler swingarm assy with axle and wheels on it. (got that one when I went down to my Dad's and brought home my CB400F that I took him to work on and also brought his 77' Cb750A home cause he figured that he was just not in good enough shape to do that sort of thing (@ 81yrs old)  I've got this thing about picking up old bikes (or part of them), like some folks pick up stray animal; (I've been known to do that too! But, not as often now.) 

                                   Take care, Bill  

[bill440cars]

The only good Honda four in 1979 was the 650. 

               That sorta sounds like you might be just a bit prejudiced there Nick.

[kghost]

The only good Honda four in 1979 was the 650. 

               That sorta sounds like you might be just a bit prejudiced there Nick.

And slightly delusional.....now 79 was a good year for honda 6's

[bill440cars]

The only good Honda four in 1979 was the 650. 

               That sorta sounds like you might be just a bit prejudiced there Nick.

And slightly delusional.....now 79 was a good year for honda 6's

               Shoulda' known that Tim would drop that line on us.

       Hey Tim, is that what year this one is?


              

[kghost]

78 but its still a SOHC 4 it just has one cam on each side 


I've got a 79 gl1000 too

[gregwaits]

There is a local guy selling a real clean '79 Gold Wing. He asks $2,500 for itm but when he learned I have a '78 750, he wants me to consider trading.

Naaaaah. 

[bill440cars]

78 but its still a SOHC 4 it just has one cam on each side 


I've got a 79 gl1000 too

                      Yeah, remember when I nominated your 78' Wing for BOTM? That's what I was thinking. SOHC and a Four! and a great looking bike, so I figured it should be BOTM material! Didn't stop and think that it had to be an INLINE all in the same line Four.

                                 Later on, Bill
 

[nickjtc]

The only good Honda four in 1979 was the 650. 
And slightly delusional.....now 79 was a good year for honda 6's

Delusional...no way; I'm a legend in my own mind. And 6's don't count in this discussion.

[Terry in Australia]

The only good Honda four in 1979 was the 650. 

Cough cough cough cough cough cough cough boat anchor cough cough cough cough cough cough

[nickjtc]

cough cough cough cough cough cough cough boat anchor cough cough cough cough cough cough

How dare you malign my trusty steed.  OK, it wasn't the nicest looking of the sohc fours (IMHO that was the 400/4) but it has proven to be a dependable, economical and easy-to-work-on steed. And the fact that, to some people, it's a little boring.......well, I have no answer to that!

[Terry in Australia]

Sorry mate, I think I'm coming down with a cold: cough cough cough cough cough cough cough cough cough 400/4's cough cough are cough cough are cough cough cough girls bikes cough cough cough cough cough cough cough cough cough...................... 

[nickjtc]

Sorry mate, I think I'm coming down with a cold: cough cough cough cough cough cough cough cough cough 400/4's cough cough are cough cough are cough cough cough girls bikes cough cough cough cough cough cough cough cough cough...................... 

Put 'em up, mincer 

[kghost]

400/4's are girls bikes .................. 

Thats why I want one 

[bill440cars]

The only good Honda four in 1979 was the 650. 

Cough cough cough cough cough cough cough boat anchor cough cough cough cough cough cough

Sorry mate, I think I'm coming down with a cold: cough cough cough cough cough cough cough cough cough 400/4's cough cough are cough cough are cough cough cough girls bikes cough cough cough cough cough cough cough cough cough...................... 

Put 'em up, mincer 

          Hey Terry, have you been to a Doctor about that cough, sure sounds like you're coming down with something there buddy.

[Terry in Australia]

Sorry mate, I think I'm coming down with a cold: cough cough cough cough cough cough cough cough cough 400/4's cough cough are cough cough are cough cough cough girls bikes cough cough cough cough cough cough cough cough cough...................... 

Put 'em up, mincer 

Handbags at 10 paces?

[nickjtc]

At least we know the meaning of foreplay, here in the northern hemisphere.

And again today I am in awe of my wonderful 1979 CB650. She's just like the Energiser Bunny....just keeps going and going and going.

[bill440cars]

At least we know the meaning of foreplay, here in the northern hemisphere.

And again today I am in awe of my wonderful 1979 CB650. she's just like the Energiser Bunny....just keeps going and going and going.