Topic: Came across 1974 cb 750 that is near mint, sitting 30 yrs

[BeSeeingYou]

What is the difference between the
Cb750F
Cb750K??
Since I am going to buy some parts I noticed there can be a diffference of oil filters between these bikes.  Other then that, the plugs, air filter, etc. appear to be the same

The first 750 f0 is 1975. The f bikes are distinguished from the k bikes by style of the tank, seat/rear pod, lack of chrome rear fender, headlight mount, no gaitors.  Performance wise they use a rear disk brake, 4-1 exhaust, higher compression and different gearing.  The frame geometry is also different.  I'm sure I'm leaving something out but you get the general idea.  Many common parts to the same year k bike but a lot of unique parts too.

One important thing....The F's are just better.

[ChuckG750f1]

What is the difference between the
Cb750F
Cb750K??
Since I am going to buy some parts I noticed there can be a diffference of oil filters between these bikes.  Other then that, the plugs, air filter, etc. appear to be the same

The first 750 f0 is 1975. The f bikes are distinguished from the k bikes by style of the tank, seat/rear pod, lack of chrome rear fender, headlight mount, no gaitors.  Performance wise they use a rear disk brake, 4-1 exhaust, higher compression and different gearing.  The frame geometry is also different.  I'm sure I'm leaving something out but you get the general idea.  Many common parts to the same year k bike but a lot of unique parts too.

One important thing....The F's are just better.

Steve- I think we need to keep that to ourselves

[Johnie]

The F's were Honda's sporty version of the CB750 bike. They called them the super sport models.

[Tews19]

K's are cooler!!!!!

[Stev-o]

Yeah, you F guys need to keep that to yourselves!

[jahmic]

Yeah, you F guys need to keep that to yourselves!

But it's so hard to hide our joy when that 4-1 screams.

To the OP, great find...good luck with the project. All the cuts bruises and cussing will be worth it when you start clocking miles with no down-time between!

[754]

 Not sure of the first 2 years of F 750s, but sidestand mount on the others is a dead giveaway..

 In my OWN experience, I find the F stuff.. FREAKING HARD TO GET RID OF for a paltry sum.. why wont someone just jump in a car opr truck, and buy thes cursed F motors off me..??  ??  ??  ?....I must live in the"F VOID of the Universe"

[Stev-o]

Hey billing - you don't have to sugar coat for him!  Something snap, dissolve or disintegrate?  A little dramatic, when was the last time that happened to you?

[BeSeeingYou]

....I must live in the"F VOID of the Universe"

I think you may have hit it on the head.....I mean Kelowna B.C.  ....that's like a Unabomber shack in the mountains.

[Stev-o]

Maybe Frank IS the unibomber!??

[Tews19]

UHHH
that bike worth 3-500 due to not running??? NUTZ I TELL YOU

[James T Kirk]

oh, i forgot to mention i replaced the air filter!




kirk out

[Trevdawg]

Well just picked it up and have it my friends place to work.  The petcock is closed tho. Its crazy because you came still see the paint marks from the factory on the bolts and such.

I noticed something missing tho.....
The push start button is missing. out of all the things

[Stev-o]

What do you mean the petcock is closed? Won't rotate??

The missing/broken starter button is a common issue, my K4 was the same. You can either kick it or jump the solenoid with a screwdriver. It is located behind the left side cover.

[Trevdawg]

I said it was closed because I assume the fluid wasn't draining down into the carbs then. I believe sometimes when these things are stored away they will forget to close the petcock and the fluid drains down. Since it was closed it just gives me a relief that the carbs might not be really really bad...
But I'm still new so we will have to wait and see how it goes

[ChuckG750f1]

I had to hot wire my solenoid for a while 'till I found a good starter switch assembly.  I kick start mine a lot because I want the new push button to last as long as possible.

When you pull the bowls off the carbs, you'll get some sense of whether they were stored dry or not.

[750K]

....I must live in the"F VOID of the Universe"

I think you may have hit it on the head.....I mean Kelowna B.C.  ....that's like a Unabomber shack in the mountains.

Hahaha, no no that's just outside of Vernon. My wife's aunt & uncle live near Vernon, a few years back 2-3 of America's most wanted we're found hiding out in the hills near them. Lots of people trying not to be found up there, not far from K town though.

[BeSeeingYou]

From the photo that bikes looks nice so I would not let it get away.  Pay what you have to to get it but try for a bit less...say 700-800.  A low mileage bike in that shape is a great find.  I found my 76F1 in the same shape.  Original owner,  not run in 25 years, tank half full, 6400 miles, clean, complete and original.  But you are still taking a chance and that has to be factored in.   Some bikes survive the long idle time just fine and others don't.  Mine required minimal work and has been trouble free for 4 years now.

[Johnie]

You are correct it is a good sign the petcock was closed. Now if your friend also drained the carbs then you will be in the drivers seat... I forgot if you had a chance to look in the tank yet, but be sure it is clear of rust and crapola as those items will close up the carb jets mighty fast. Do not be in a super hurry to start it up. Take your time, get a new battery, change the oil & filter, and save a little oil to squirt into the 8 valve adjustment holes on the top of the valve cover (17mm). That will give some fresh oil to the top of the motor when you first turn it over. Put in some new spark plugs and see what you got. Of course, how it starts and if it starts all depends on the condition of the carbs. I would also suggest once you have the oil changed check to see if you have spark to all plugs. Good luck and let us know how you come out.

EDIT: A side note...when you change the oil you will be removing 3 things:
1.) Filter (be careful not to round the filter bolt as this happens a lot)
2.) Oil pan drain plug.
3.) Oil tank drain plug.

Just wanted to mention that as if you did not have the manual some forget about the oil tank.

[Brantley]

Nice score, Trevdawg.

I noticed something missing tho.....
The push start button is missing.  out of all the things

This may seem obvious for a bike you bought not running, but make sure yr in neutral or the bike's on the center stand when you put yr fresh battery in. That push button completes the starter solenoid circuit by a single ground to the bars. The K4 has a clutch and neutral starter lock out, but lots of folks have bypassed them. So if that wire is loose grounding out in there... The good news is the button and spring are the same in all CB/CL's thru '74 so you don't have to search for a 750 specific one if yr gonna repair yours.

[Trevdawg]

well carbs are freed up now and operational. One of the return cables is snapped but they still operate fine from the throttle. We pulled the plugs and managed to get it to turn. Unknown to me. My friend rotated it from the kickstart and all that stuff we sprayed in the cylinder came right back out of cylinder #4 and landed all over my shirt. NOT COOL!

Brake fluid . . . check


owners manual . . check

and a second below the seat that the owner forgot about. .




leaky head gasket on cylinder 1. . maybe it will be better when the bike starts to run
(let me know your opinions about this one) I am not ready to fix this . . . just yet.

[Stev-o]

Brake service appears to be in your future!   I would concentrate on doing a start up on the motor to see what you have. Head gasket leak is minor and common, don't worry about that for now. 
Change oil, charge battery, clean out tank, check carbs and report back. Good luck.

[Johnie]

10-4 Steveo...good points there. That gasket leak is so common most of the bikes had them. Design deal back in the 70's. The general rule is not to do anything with it unless it gets real bad. Wait and see if you need some major head work then do the gasket. Some guys stuff 1/4 inch nylon rope in between the fins there to keep it in check. But yes, you will need front brake caliper and master cylinder work. The kits for both are still available from Honda. If you or your buddy can not do it try the local Honda shop. Or maybe there is a local forum member in your area to walk you through it.

[Trevdawg]

The vins are a little different too
CB750 - 2333350
CB750E - 2339139

[Stev-o]

Normal. The frames and engines were made in different factories.