Topic: 1978 CB750 F (Super Sport)

[hiljak]

I have just acquired this 1978 CB 750 F. She's been in a barn for about the last 5 years and I really know very little about her history. Here is all I know. She was sold to the guy I bought from about 7-8 years ago. He sat it in his shop until his shop closed then he moved it to the barn. He said when he bought it the guy used a car battery to jump it and fire it off by spraying some starting fluid in the open carbs. He said if ran about 15 seconds (so who knows what I have yet to uncover). The bike doesnt have a key not for the ignition or for the fuel lid (no lock mech). The motor seems to turn over correctly with the kicker.

I'll be stripping her of all the turn signals, instruments and such. I am wondering if the best place to start is with a fresh battery and see what works and what doesnt. Any suggestions of the sequence of that of which I should check?

I am not certain yet but I am inclined to Cafe her.
Couple of early questions:
1. Are the factory wheels of any value or do most people replaced them?
2. Carbs look rough, while I've rebuilt/jetted a similar set of carbs in the past, how can I verify the carbs are factory? What size should the carbs be?
3. How much would a whole new set of good, used carbs cost me?
4. The bike came with no title. Which company can I speak to about getting an official title for this bike?
5. Anyone aware of any cool cafe kits out there for the Super Sport?
6. Anyone have any cool Super Sport pics they can share for inspiration?

[BobbyR]

I have 78K. Your carbs from appearances are coffin tops which are correct. The wheels are very desirable. 

If you take the lock cylinder out using the two fasteners holding it in place you can get the lock cylinder number and they can make you a key. If you separate the white plastic switch from the lock cylinder you can turn the top of it to operate the bike while you are working on it. A 2 amp charger or car battery can be used while you are sorting thins out.  You will have to tear the carbs down and clean them well. You have an accel pump which will have to really be cleaned well. They hold a small amount of fuel and they gum up quick. Nice looking bike. You could go stock or Cafe depending on the amount of time you want to spend. New Tires should be on you list. 

[hiljak]

Thanks BobbyR
I intend to clean carbs thoroghly. I'll likeky just run air pods because they are simple unless someone else has a better recommendation.

I thought there might be something about those wheels. While I'm not a fan of them I seem to recall someone telling me they were desirable.

Is the accelorator pump at the bottom of the bowl area on the second carb in on the left side (while setting on the bike) of the bike? All of the carbs look the same except that one. I couldnt tell exactly what was going on there.

New tires are indeed on my list. Likely Shinkos since the are cheap and this will not be an everyday rider.

[Bankerdanny]

Swapping to pods means rejetting, which is harder on the 77-78 F bikes due to a different method of jet installation.

What state do you live in? Some states are very easy to get a new title, some a very difficult to impossible.

First I would check with your own state's DMV website. If it is a hard/iumpossible state then come back here and search 'vehicle titles' there are a number of threads on how to deal with this issue.

[excellrec]

1. Are the factory wheels of any value or do most people replaced them?

I see them come up on ebay for cheap fairly regularly and I most often see people replace the comstars with spokes.  Thus, it seems to me the comstars are the least valuable of the wheels.  Also, they aren't supposed to be disassembled (i.e. the spokes from the hub), I accidentally did that.

2. Carbs look rough, while I've rebuilt/jetted a similar set of carbs in the past, how can I verify the carbs are factory? What size should the carbs be?

The F2 has the accelerator pump on Carb 2 (from the rotor side of the motor).  It sounds like yours is a stock set, the main jets are also smallish (I think 100-110?) from the factory.

3. How much would a whole new set of good, used carbs cost me?

I'd probably just buy ebay rebuild kits for $40-50 bucks and dunk the ones you have.  Also, if the boots (carb to head) are shot, those are about $90.

4. The bike came with no title. Which company can I speak to about getting an official title for this bike?

No idea.

5. Anyone aware of any cool cafe kits out there for the Super Sport?

Not aware of any kits, but there are always the usual places that make the cafe tanks and seats.  In my opinion, however, the F2 is the closest to cafe style in stock trim because of the rear cowl and more elongated and less bulbous tank.  As such, I chose to simply push the stock trim in a little sportier direction, as opposed to swapping out the tank and seat and etc.

6. Anyone have any cool Super Sport pics they can share for inspiration?

The nicest one of these I've seen was done by a forum member here- http://forums.sohc4.net/index.php?topic=68722.800

P.s., you should also be happy to know that the F2 has the most powerful engine of the 69-78 cb750 sohc line (that's what it says on paper anyways).  This is to some extent due to the stock 4-1 exhaust setup, larger intake valves, hotter cams, increased c.r., and maybe carbs? Also, we get dual discs in the front stock.   

[pmurph1x]

I have the same bike. Even the same color.
- For the Carbs they were gummed up pretty bad so I removed the bowls, floats and jets and gave them a good cleaning with carb cleaner spray. Shoot the spray through all the gas orifices to clean them out - wear some eye protection.
- For the accel pump I removed the 3 screws and dropped the diaphragm and cleaned out that area. I guess I got lucky, when I put the pump back on the bowl I put some carb cleaner in the bowl and manually pumped the diaphragm. The carb cleaner squirted right out.
- The other carb issue I had was they would leak fuel. I found the rubber tips on the needle valves were hard so I ordered 4 rebuild kits from partsnmore. Put them on over the weekend and re-setup the float heights. No leaks so far.

Still need to get a title - that is the next part of my project. I dont want to put any more money into it until I know I can title it.

  Good luck Paul

Edit - Might not want to let carb cleaner come in contact with the diaphragm. My diaphragm now has two holes in it and no longer pumps. I suspect the carb cleaner may have had something to do with this. Ordered another one.

[BobbyR]

Thanks BobbyR
I intend to clean carbs thoroghly. I'll likeky just run air pods because they are simple unless someone else has a better recommendation.

I thought there might be something about those wheels. While I'm not a fan of them I seem to recall someone telling me they were desirable.

Is the accelorator pump at the bottom of the bowl area on the second carb in on the left side (while setting on the bike) of the bike? All of the carbs look the same except that one. I couldnt tell exactly what was going on there.

New tires are indeed on my list. Likely Shinkos since the are cheap and this will not be an everyday rider.

Yes that is the accel pump. You will see a thin rod going to it from the upper linkage. You may of may not need a rebuild kit. You will need to pull the slow jet emulsion tubes which are pressed in. With a pliers you lightly grip the tube so as not to make it oval. You kind of wiggle and lightly twist them and they should pop out. The MBTE they used in the gas a few years ago leaves white deposits which nothing seems to dissolve.

To clear the white crap from the holes you have to pass a strand of copper wire from a lamp cord or high E guitar string through them. You should use the wire on any port inside the carb bodies. Once you have passed the wire through anything use some carb spray to flush out the loosened crap.

Ebay carbs may not be in any better condition than what you have now. My advice to you is to take your time and do it carefully. I know this, I was always in a rush and I had them off 4 times. Finally did it right and have had no issues for 10 years.

The look is what you want it to be. The F was kinda Cafe and can be more so with some select parts.

[rwinn]

New here as well and picked up the same model same year so I'll be watching. I just cafe'd a 79 KZ650 which was a blast! As for inspiration I go to Google Images and type in 78 CB750 super sport cafe racer. There's a few nice pics there. Plus check out the gallery. Some very nice examples!

[deafcaferacer]

Need to go to the DMV to get a new title. As long as all the serial numbers are there and intact, that will not be a problem. Probably a good idea to call them first to see what they require for retitling.. probably a bill of sales, etc.

[hiljak]

I'm reading these and intend to reply when I get to my computer tomorrow but I had a quick question. How does one tell the difference between a F1-F2-F3?

I had a 1971 K2 before so I understand the basics but help me understand the super sport. As I understand it F just denotes Super Sport but what about the 1-2-3?

[MOONDOGNYC]

6. Anyone have any cool Super Sport pics they can share for inspiration?

The nicest one of these I've seen was done by a forum member here- http://forums.sohc4.net/index.php?topic=68722.800

Yup....that is the nicest one on the forum...

[Bankerdanny]

Go to the model thread for 750's and see the model guide. But i belive the Comstars were F3 only.

[CB750F2]

I hope that you decide not to cafe that bike. The bike would clean up very nicely. I would be over the moon to find somthing like that here in Australia. Good luck with what ever you decide to do. Pat

[ekpent]

I'm reading these and intend to reply when I get to my computer tomorrow but I had a quick question. How does one tell the difference between a F1-F2-F3?

I had a 1971 K2 before so I understand the basics but help me understand the super sport. As I understand it F just denotes Super Sport but what about the 1-2-3?

Actualy the 1971 is a K1. F0-1975,F1-1976,F2-1977,F3-1978.

[hiljak]

I'm reading these and intend to reply when I get to my computer tomorrow but I had a quick question. How does one tell the difference between a F1-F2-F3?

I had a 1971 K2 before so I understand the basics but help me understand the super sport. As I understand it F just denotes Super Sport but what about the 1-2-3?

Actualy the 1971 is a K1. F0-1975,F1-1976,F2-1977,F3-1978.

Very well. Thanks for the clarification.

[andy750]

I hope that you decide not to cafe that bike. The bike would clean up very nicely.

+1

If you do cafe it then Id buy the tank/seat from you. 

[cabrala]

More "F" inspiration that'll give Tweakin's bike a run for its money

Enter Doctor_D...

http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479

Both are fantastic examples of what these old bikes can be.

[hiljak]

More "F" inspiration that'll give Tweakin's bike a run for its money

Enter Doctor_D...

http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479

Both are fantastic examples of what these old bikes can be.

Wow...both of those bikes are badass. Very Cool. Thanks to everyone for sharing.

[BobbyR]

If the speedo and tach or just the tach is in good shape i will by that.

[hiljak]

If the speedo and tach or just the tach is in good shape i will by that.

As it stands right now, I do not intend to run any unnecessary lights or instruments. I'll either keep what I take off or put it up for sale. I'll keep in mind that you might want the speedo/tach.

[HonderCB]

Those are stock PD carbs, the accel pump is that thing on number two bowl, it squirts fuel into your carb when you twist the throttle to take away hesitation between the idle and main jet.  Its a pretty sweet set up when working properly.  Pods are a bit of a pain on these bikes, if you can find a stock air box and put in 110 main jets (stock is 105) it will really wake it up.  The pods do look cooler, though.  If you are looking for a new set of carbs try SOHCDigger.  He rebuilds carbs and would probably sell you a set if he has any extra, or if your carbs aren't in too bad of shape he could rebuild them if you don't want to do it.  price is reasonable.  He did mine and they are great.

Those wheels aren't that valuable.  They are more desirable than then second generation comstars (which are hideous IMHO) but most guys ditch em for spokes.  You can buy a GL1000 front fork setup to swap out that way you still can run dual discs.  That is what many have done.  I personally like the first gen comstars, so i'd keep em

Go to the model thread for 750's and see the model guide. But i belive the Comstars were F3 only.

They were on the F2 and F3 (77-78)

Its a pretty nice lookin bike the way it sits.  I wouldn't café it, but that's just me.  If your desire is a more sporty bike you could always leave it as is, but replace the bars with some clubmans or clip ons and swap out for a set of rearsets.  Then you would have the best of both worlds, while still retaining a somewhat stock look and the ability to ride 2-up.  These F model bikes were designed with a little bit of a café theme anyway (thus the tail section.)

I'm biased because I LOVE the stock supersport bikes, but you can certainly do with it what you wish, its your bike.  I also don't hate on cafe'd super sports, I love Tweakin, BrandEn, and DoctorD's café bikes.  They are pretty sick.  Here is some stock supersport porn for your viewing pleasure, courtesy of Kap384, he probably has the nicest on the site as far as completely stock goes: http://forums.sohc4.net/index.php?topic=66779.75

Good luck with your bike

[hiljak]

^^^^^Thanks for the info HonderCB^^^^^^^^

I'm not sure what I'll do with her yet. I first want to make certain there are no major motor issues so my primary objective is to get her running and see how she performs. Then I'll get to all the cosmetics and style issues.

I'm thinking I'll likely cafe her, strip her of all unnecessaries, add wire wheels and bars and such.   Then just ride the piss out of her.

[bollingball]

^^^^^Thanks for the info HonderCB^^^^^^^^

I'm not sure what I'll do with her yet. I first want to make certain there are no major motor issues so my primary objective is to get her running and see how she performs. Then I'll get to all the cosmetics and style issues.

I'm thinking I'll likely cafe her, strip her of all unnecessaries, add wire wheels and bars and such.   Then just ride the piss out of her.

Do want you want it is yours. I would only say offer all parts you don't want to members here. I don't want any. Just saying all these guys give help so why not

Ken

[Xnavylfr]

GL1000 forks won't fit CB750 triple trees!! They are larger diameter tubes  and you have to use the GL triple trees also!!!


Xnavylfr(CHUCK)