Author Topic: New guy here with a question about a 70 CB750 (Read 7372 times)

gravygrabber · « **on:** March 13, 2013, 08:32:46 PM »

Hi everyone.
Got a chance to buy a 70 CB750 from a co-worker. Co-worker tried to get it going and lost interest. It's a 70 suppose to have the original engine. The engine number is CB750E-101XXX.
I know the earlier bikes are more sought after. It's not a sand cast motor or anything. It's quite a basket case I think. He had a lot of work done to the engine, fired it up and rode it maybe 10 miles and said after it won't start anymore and he's not sure why. He tried adjusting valves again and still no bueno. He questions the battery state. It could be easy or it could be something bad. Not really sure. It did crank over okay when I looked at it.
I think he was going to cafe this bike but I'd like to return it to a clean original rider if possible.

Would you guys save it? He's wanting $600 for it as is. Seems like an ok deal to me. It has a title and tags which a hassle to get here in CA. once the bike is out of the system.

754 · « **Reply #1 on:** March 13, 2013, 09:00:01 PM »

Great deal if its not all butchered frame and stuff.. And how much correct stuff is there..
If serial is in the 10*** range, made in Nov. Or Dec 69.. But ,usually registered as a 70.. That would be considered early diecast

gravygrabber · « **Reply #2 on:** March 13, 2013, 09:29:14 PM »

Quote from: 754 on March 13, 2013, 09:00:01 PM

Great deal if its not all butchered frame and stuff.. And how much correct stuff is there..
If serial is in the 10*** range, made in Nov. Or Dec 69.. But ,usually registered as a 70.. That would be considered early diecast

Frame isn't all butchered but it really it needs to go down to the frame and be sandblasted and repainted/powdercoated. I was thinking because it was a 101XXXX serial it was made in 70. It's kinda weird the guy took it apart, replaced some bad studs and then had a guy who's a Triumph and old Honda guy put it back together. He said the previous guy tried to install bigger pistons out of another bike and (homemade big bore?) and he ended up getting the right pistons and got some replacement jugs I guess. The guy who buttoned it up did a valve job on it I believe.
Doesn't have side covers, front fender, original exhaust

,
That's what I can tell so far.
Does have a repro wiring harness that's brand new never installed. That's a plus since the wiring looks pretty effed up. I was at the motorcycle swap and grabbed a vintage Honda electrical manual and I gave it to the guy to help him out. He has a manual too. All that goes with it. I think he has a box of odds and ends.

I'd really like to save it. I've been looking for a CB750 to fix up for awhile. I got hooked on 2 stroke street bikes from the 70's for awhile but always wanted a CB750.

70CB750 · « **Reply #3 on:** March 14, 2013, 03:23:56 AM »

Due to SOHC compatibility you can piece it together from available parts. Mind you, it willl not be original, but reliable vintage bike that's fun to ride around and put some serious miles on.

I say it is a good deal, the K0 were the most powerfull of the lot, go for it and good luck

Stev-o · « **Reply #4 on:** March 14, 2013, 06:55:25 AM »

Buy it!

gravygrabber · « **Reply #5 on:** March 14, 2013, 11:13:59 AM »

I want to go for it just a little scared its going to cost a fortune to get back to a decent bike. I see they go for decent money of feebay

MoMo · « **Reply #6 on:** March 14, 2013, 11:29:01 AM »

600 is a good price but if you are not mechanically inclined it will cost a fortune. There is plenty of help and free manuals to download on this forum so go for it

. and welcome...Larry

Johnie · « **Reply #7 on:** March 14, 2013, 02:20:30 PM »

Go get it...$600 is a steal for a KO. If you decide to sell it you will get that plus some for your investment. The are a number of guys here that will pay more for that bike so you could probably sell it to someone on this board and not lose money.

Stev-o · « **Reply #8 on:** March 14, 2013, 06:54:22 PM »

Buy it!

greenjeans · « **Reply #9 on:** March 14, 2013, 06:58:44 PM »

Can you confirm the serial numbers....

Is it 101XXXX or is it 1001XXX ?

Had a sandcast titled as a '70

gravygrabber · « **Reply #10 on:** March 14, 2013, 08:41:18 PM »

Quote from: greenjeans on March 14, 2013, 06:58:44 PM

Can you confirm the serial numbers....

Is it 101XXXX or is it 1001XXX ?

Had a sandcast titled as a '70

CB750E-101XXXX Doesn't look like a sandcast but it's still an early bike right?

Johnie · « **Reply #11 on:** March 14, 2013, 08:42:36 PM »

Steve-0...what do you think he should do???

Stev-o · « **Reply #12 on:** March 14, 2013, 08:43:30 PM »

Quote from: Johnie on March 14, 2013, 08:42:36 PM

Steve-0...what do you think he should do???

Send me the phone number so I can buy it!

Don R · « **Reply #13 on:** March 14, 2013, 08:47:38 PM »

As mentioned above it's probably a nov or dec 69 build date. Called a diecast they are desirable to own. Mine is 1014100 and was built in Nov 69. It's a deal grab it if it's mostly good. You could easily get your money back if you decide to sell.

gravygrabber · « **Reply #14 on:** March 14, 2013, 08:49:43 PM »

Quote from: MoMo on March 14, 2013, 11:29:01 AM

600 is a good price but if you are not mechanically inclined it will cost a fortune. There is plenty of help and free manuals to download on this forum so go for it . and welcome...Larry

Actually I'm a Master Honda auto tech. I also have a 2 year motorcycle program certificate from the community college I got for fun a couple years ago. I tried my hand working on motorcycles to for a Honda and Harley dealer but in the end it just didn't pay enough to justify doing it for a living. I've never taken a bike to bare frame and built it back up and raised it from the dead though. I'm sure I could learn a thing or two. One benefit for me is coming up through the ranks over the years at the Honda dealer I know a couple of Honda guys that started out in the motorcycle side working on CB's when they were new. They have a ton of knowledge about the bikes. One was telling me the other say about how the cams were not line bored on the DOHC engines and they would make noise on the side stand idling but not while running. Also said they used to pull the cam bearing cap and plastic gauge them then machine/sand them down to take out the slop.

gravygrabber · « **Reply #15 on:** March 14, 2013, 08:50:55 PM »

Quote from: Don R on March 14, 2013, 08:47:38 PM

As mentioned above it's probably a nov or dec 69 build date. Called a diecast they are desirable to own. Mine is 1014100 and was built in Nov 69. It's a deal grab it if it's mostly good. You could easily get your money back if you decide to sell.

This one is earlier by at least 1000 bikes.

754 · « **Reply #16 on:** March 14, 2013, 09:10:45 PM »

Basically its worth grabbing, but some of what you said is missing starts to add up If..If.. You want to be correct. Sidecovers, front fender, you said were not there, hope it has the carbs, correct tank, guages seat switches.. But even if none of its there grab it..

I paid. Over 1/2 that for #10*** lower end with rod damage, and it had had water sitting in it.. Just the cases and the junk inside..

gravygrabber · « **Reply #17 on:** March 14, 2013, 09:21:13 PM »

Quote from: 754 on March 14, 2013, 09:10:45 PM

Basically its worth grabbing, but some of what you said is missing starts to add up If..If.. You want to be correct. Sidecovers, front fender, you said were not there, hope it has the carbs, correct tank, guages seat switches.. But even if none of its there grab it..

I paid. Over 1/2 that for #10*** lower end with rod damage, and it had had water sitting in it.. Just the cases and the junk inside..

Don't mean to sound like a dummy but isn't the die cast engine the same all the way up into the 80's? What makes the 70 more desirable than the late 70's SOHC?

754 · « **Reply #18 on:** March 14, 2013, 09:28:36 PM »

There are many differences, even between early and late KO.. Earlier = more desireable... An early diecast should be worth double what a 74 is worth.

scottly · « **Reply #19 on:** March 14, 2013, 09:38:45 PM »

Quote from: gravygrabber on March 14, 2013, 08:49:43 PM

they would make noise on the side stand idling but not while running.

Huh?? How can a motor be idling but not running?

Stev-o · « **Reply #20 on:** March 14, 2013, 09:46:23 PM »

Quote from: gravygrabber on March 14, 2013, 09:21:13 PM

Quote from: 754 on March 14, 2013, 09:10:45 PM
Don't mean to sound like a dummy but isn't the die cast engine the same all the way up into the 80's?

No. The single overhead cam (SOHC) 750's were last made in '78, then Honda switched to DOHC. They were "detuned" over the years for EPA reasons, but for general riding, even the '78's were still quick (I have one). The DOHC are not as valuable or collectable...yet.

gravygrabber · « **Reply #21 on:** March 14, 2013, 10:32:29 PM »

Quote from: scottly on March 14, 2013, 09:38:45 PM

Quote from: gravygrabber on March 14, 2013, 08:49:43 PM

they would make noise on the side stand idling but not while running.
Huh?? How can a motor be idling but not running?

sorry riding? I guess the noise is pretty bad on the side stand as the cam tends to bounce around in it's bores. I dunno I never heard one do that but I have heard some sketchy cam chain noise on these bikes.

goldarrow · « **Reply #22 on:** March 14, 2013, 11:15:23 PM »

Just buy it, we want to see pics

gravygrabber · « **Reply #23 on:** March 14, 2013, 11:34:17 PM »

Quote from: goldarrow on March 14, 2013, 11:15:23 PM

Just buy it, we want to see pics

I'll try tomorrow. I'm so busy at the shop right now I can't get over there after work to pick it up. He actually told me he would take $550 and I told him let's just make it an even $500 and he said okay. It's not that nice though guys. Definitely been apart a bunch of times and I think one of the jugs has a fin broken off. I'm going to try and do something tomorrow with it. Pics to come~~

gravygrabber · « **Reply #24 on:** March 15, 2013, 02:29:02 PM »

UPDATE

Pulled the trigger and went at lunchtime and bought the bike. I'm still thinking I paid too much at $500 but time will tell

News:

Author Topic: New guy here with a question about a 70 CB750 (Read 7372 times)