Topic: Looking to buy a CB750, but have a couple questions

[camelman]

Hi all... I'm back!!!  First off, if anyone has need of an adventure bike in Colombia, then let me know.  I still have my 2014 Suzuki GS150r (amazing adventure bike that always got over 90 mpg) down there sitting in a friend's house.

Okay, CB750 time.  I'm going to look at a CB750 Wednesday morning.  It is a barn find supposedly with a big bore kit (836 or something like that?).  The plate shows it was last titled in 1979, so I figure it should just need gas and a new battery.    I am going to restore it roughly to original if I buy it.  I don't have the space for a frame off, so it will be an in-frame resto.  I need to source a few new/replacement parts, remove a broken spark plug, and generally clean it up.

A few parts are missing that I'm trying to figure out.  Please help me with the following:
1) Did 1973 750s come with a grab bar?  If so, then what did it look like...side mount or wrap around?
2) Does the seat latch bracket bolt onto the frame, or is it welded?
3) Any recommendations on sourcing a new replacement seat?

Thanks,
Camelman

[flybox1]

camel...i sold my 350F and went right for a 750, and its been awesome.
grab bars fronts mounts were bolted at the rear shocks, and looped around.  they also had a 2nd bolt on either side which ran straight thru to that hole at the end of the upper frame rail (that usually gets cut off for a hoop)
I have one on my K8 and its pretty sturdy.
Seat latch and hinges are welded to the frame
Replacement seats can be found, but so are recovers.  check on ebay for cover/foam kits.
good luck with your purchase. here's to hoping it turns over 

[Old Scrambler]

+1 with Snohomish...............the K3-K6 bars are interchangeable and have tabs to mount the rear signals.  The stock K3 came with 105 main-jets. A K&N filter and 120-mains will wake them up.

[camelman]

Gents, thanks for the replies.  Do you mind picking out the issues with this bike?  Here's everything from the craigslist post:

Honda 1973 CB750 K for sale. It was found in a barn with 7,800 miles. I took a couple of minor electrical parts for my 76 CB750 F but other than that it is stock and in great shape with very little rust here and there. Motor is clean and ran before I broke a spark plug thread and put it in storage. The previous owner said it has a 836 big bore kit. I haven't tested compression but it sounded pretty mean when I fired it up. The tank has a very small ding or two but remarkably has no rust inside. The wheels and spokes look great but the tires are obviously done.

I'm in no hurry to sell it but it doesn't seem right that it is just sitting in storage, so here it is listed on CL to see if somebody would like to buy it. If you are interested make me a serious offer and we can go from there. I'm also open to trade it for a running dual sport.

I'm thinking of offering around $400. 

Camelman

[Tews19]

It has 4-4 pipes. Any rust holes in them? If not rust holes the pipes are worth that alone.

[flybox1]

id want to see the broken spark plug thread and get some ideas on how it might come out.
sounds mean 'cause the pipes are hollow    the seat sucks.
needs side covers, and a good scrubbing.
Reminds me of mine, and I paid $700 for it

$400(titled) is a good deal.  Id take it home.

[SOHC4 Cafe Racer Fan]

camel...i sold my 350F and went right for a 750, and its been awesome.
grab bars fronts mounts were bolted at the rear shocks, and looped around.  they also had a 2nd bolt on either side which ran straight thru to that hole at the end of the upper frame rail (that usually gets cut off for a hoop)
I have one on my K8 and its pretty sturdy.
Seat latch and hinges are welded to the frame
Replacement seats can be found, but so are recovers.  check on ebay for cover/foam kits.
good luck with your purchase. here's to hoping it turns over 

All good advice.

NOTE: if the bike has been sitting for 35 years, the carbs are probably in dire need of an ultrasonic soak and rebuild.  Gas degrades (especially ethanol based gas) if not stabilized and gums up carburetors.  You will be extremely lucky if all you need to do is replace a battery and gas up. 

If the bike has been sitting for 35 years, you will most likely need to replace gaskets in the motor.  If you cannot deal with having the motor pulled if necessary to replace gaskets (if that's a deal-breaker), get a modern bike or buy a freshly rebuilt motor WITH a warranty.

You will also want to look the bike over carefully as to cables, brakes and suspension.  The forks will likely need new fork oil and seals at a minimum.

This is not your bulletproof modern adventure bike.  This bike requires care and feeding. 

From your additional comments, the bike has a broket spark plug thread which you will need to repair before you get it running.  You should have the compression checked on the motor.  More important, you should make sure the motor is NOT seized from sittting for 35 years.

$400 sounds like a VERY lowball offer you are making.  This bike will need work.  Be prepared to learn how to DIY and/or know a good vintage bike mechanic to help you.

[martin99]

Don't underestimate what may be involved with that sparkplug thread (just in case no-one mentioned it ).

Even without all the other considerations, that could be the deal-breaker for you. Unless it's got a frame kit, you'll have to separate the motor from the frame to remove the head. Don't know how you could be sure you didn't leave any nasties on top of the piston otherwise.

[bjbuchanan]

The spark plug removal is gonna take that sucker out of the frame, I can guarantee it. You can remove the plug if it is 1 or 4 with it in the frame but you will never know if any bits fell in to the cylinder

The latch isn't welded. It is bolted up top and behind the key latch

IDK about your area but the fact it has a title and isn't a total hunk of crap means to me it is worth buying. Parts alone, blah blah you have read it before.

If anything, strip what is necessary to remove the engine. Put everything back where it was so it is a whole bike, minus motor and work like that. I rebuilt my ebay 836cc outside in november in NY this year with mostly hand tools. The only special tools necessary are a torque wrench

[PeWe]

Not been used for 35 years... really do not need to open the engine and replace all rubber stuff inside?
Valves + seats might have severe rust + cylinders, piston rings....

Carbs must be cleaned if they have had fuel during some years. My old OEM carbs became really clogged during 19 years of no use. Must be disassembled completely and cleaned. might have corroded parts anyway.

If I should be lucky to find an old barn find like that, I would take it to pieces and do it properly with joy. I think I'm too late to find a K0 here which I really want to find for a good price.

EDIT: $400US is almost nothing!
Impossible to find that here. Minimum $2000 for a bike like that. All parts with good 4-4, low mileage double it again....

[ekpent]

Is it just me or does something look different around those rear blinkers which are not stock like something was welded on or something. For so low of supposed miles it has been farked around with a lot. Missing parts, crap paint etc. Your offer of $400.00 sounds about right if you can't hear it run. Check the engine numbers to see what year they really are.

PS-Grab bar years are 72-74 are compatible and 75-76 are compatible because of turn signal differences.

[camelman]

Ekpent,

I saw the same in the pics about the rear turn signals.  Plus, it looks like there are globs of weld just in front of the rear left turn signal.  I have a feeling this bike has been changed a lot from stock, which might be a deal breaker for me.  However, I'm coming to grips with the engine coming out due to all the comments, and I think that is a good idea to replace seals and get a good look at the engine internals.

Camelman

[camelman]

I looked at the bike this morning and decided to pass on it.  Three of the four exhausts had rust holes in the bottom, the #2 spark plug was definitely broken off, various parts were missing including some pricey items to acquire and there were a lot of loose bolts.  For someone with a pickup truck, spares in the garage and plenty of space to work, I think this would be a good project, but it's not for me.
On the plus side, the structural components all looked clean and straight, the engine looked clean and there were no obvious leaks, the wheels looked good and the wiring was not butchered.  The bike is on the San Francisco craigslist site.

Thanks to everyone for the feedback.

Regards,
Camelman

[Stev-o]

Looks like the fender is welded to the frame.

[mrbreeze]

As close as I can see it.............looks like some kinda sloppy weld job on the frame tube under the hoop for the rear fender/seat. The turn sigs are the big uns' from a 75-76 model. If a guy had the right tools and a clear shot at it ...might be possible to get the broken plug out with the engine intact. For $400.....even if you did have to yank the head.....what better time than now to install a frame kit from Gordon. If the motor turns over and has clean title (especially here in Cali.) I would say its worth looking at for 4 bills.....maybe less after closer inspection of the welding on the frame and anything else you can find in person.