CB750 K0/K1 Hybrid

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Lucien Harpress
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Re: CB750 K2- Much Better

#181

Post by Lucien Harpress »

Thanks for the advice. I'll keep it in mind. The engine work is something I might look forward to in the future, if any of the head gasket leaks get too bad.

That said, the "value" in this bike is definitely it's ability to get my behind down the road. It is the Frankstien-iest of Frankenbikes, registered as a '75 because that's the cheapest titled frame I could find for it. And I kinda dig the early rear-end setup, which is why I kept it. Heck, the only original K2 parts on it are the engine and the gauges. If it can get from A to B without breaking down and keeping MOST of it's fluids inside, that's good enough for me.
1997 Valkyrie- Light Cutomization, but Too Busy Riding
1980 KZ1300- Bike's Haunted
1976 GL1000 (Yellow)- It Runs (Poorly) and Doesn't Leak (Mostly)
1974 Velosolex 3800- Better Than Walking
1972 CB750- Broke the Chain And Ate the Motor
1969 CT90- The Most Fun You Can Have on 90ccs.
1965 CA77 Dream- Needs a Full Teardown, but Complete

All advice I give is only valid until an expert corrects me.
Don R
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Re: CB750 K2- Much Better

#182

Post by Don R »

I love the bike, didn't notice the 71 style parts. The head looks 71 too. Those things may have come on that bike. Often an unsold bike sitting in a dealership got a new title when the calendar changed. It could be a 1972 and still be a K1. What's important is that you like it never mind the details. Mark Paris said they mixed parts during the model change too. His bike has the k2 seat latch but you can see where it had a k1 latch on it first.
In 75 Honda got sued for re-titling bikes and stopped doing it. Then they went right into 76 production around April 75, that's why these are fewer 1975 bikes than 1976's.
My K2 is a true frankenbike, it's got k2 gauges, rear fender, taillight and seat with a K1 engine and front fork assembly. But mine has no frame tag or numbers indicating a replacement frame so mine is most likely a hybrid made from one or more wrecks. I plan to bolt on every 70's hot rod part I can find, ARD mag, Weber carbs, dual discs, Fibermold gas tank, Daytona seat, Yoshimura clone header etc.
78 GL 1000, 70 CB750 sandcast, 70 CB836 hot rod, 1124cc 750 dragbike resto project.
You don't need a weatherman to know which way the wind blows.
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desertrefugee
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Re: CB750 K2- Much Better

#183

Post by desertrefugee »

Liam wrote: Sun Apr 04, 2021 9:01 am
Lucien Harpress wrote: Sat Apr 03, 2021 5:20 pm
And this bike isn't going to win any awards for beauty anytime soon, so they kinda fit in.

I beg to differ. Shes a beauty in my eyes.
Mine too!
- Life is not about waiting for the storms to pass. It's about learning to ride in the rain.
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Re: CB750 K2- Much Better

#184

Post by desertrefugee »

And I guess you know that every time you trot out another edition in the saga of your 750, it makes me pine to get going on the one I have. It keeps getting preempted by other bikes, but that’s mainly because when I do finally get around to it, I want to do it right. However, in this case, right is a mild custom. It almost seems as though with the late SOHC 750s, the K models are more desirable than the F series. Can that be right? Plus, it’s a heck of a lot cheaper to make a nice custom went to restore one to factory specs.

Maybe next year…
AB4ED987-4F0C-41BE-93A0-4F5DF4D4E106.jpeg
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- Life is not about waiting for the storms to pass. It's about learning to ride in the rain.
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Lucien Harpress
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Re: CB750 K2- Much Better

#185

Post by Lucien Harpress »

Even since I bought it the bike's been a bit of a hodgepodge. The bike was repainted, but the color is identical to what it originally had. Original (rusted out) frame said '72, but titled as a '73. And then the carbs were the really early four cable design. And that's not including the smaller rear rim with larger back tire, sissy bar, velocity stacks and ape hangers.

It has led an interesting life.
1997 Valkyrie- Light Cutomization, but Too Busy Riding
1980 KZ1300- Bike's Haunted
1976 GL1000 (Yellow)- It Runs (Poorly) and Doesn't Leak (Mostly)
1974 Velosolex 3800- Better Than Walking
1972 CB750- Broke the Chain And Ate the Motor
1969 CT90- The Most Fun You Can Have on 90ccs.
1965 CA77 Dream- Needs a Full Teardown, but Complete

All advice I give is only valid until an expert corrects me.
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Lucien Harpress
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Re: CB750 K2- Much Better

#186

Post by Lucien Harpress »

In a surprisingly rare occurrence, I popped a gauge on some aspect of this bike to get some numerical data instead of just "being surprised how well this runs on it's own". This time was a timing light, just to see how spot on the ignition timing ACTUALLY was. I learned a couple things:

--Header pipes, when warm, melt wire insulation REAL well.
--1-4 was dead-on, while 2-3 was surprisingly close.
--The points for 1-4 looked good, while the 2-3 points were sparking like crazy.

I'm thinking I've got a bad condenser on the points for 2-3, judging by the light show that set was giving me. With how easy it is to replace, and how cheap they are, I've got a new one coming. It didn't seem to hurt how the bike ran too much, but there's not reason NOT to replace it.
1997 Valkyrie- Light Cutomization, but Too Busy Riding
1980 KZ1300- Bike's Haunted
1976 GL1000 (Yellow)- It Runs (Poorly) and Doesn't Leak (Mostly)
1974 Velosolex 3800- Better Than Walking
1972 CB750- Broke the Chain And Ate the Motor
1969 CT90- The Most Fun You Can Have on 90ccs.
1965 CA77 Dream- Needs a Full Teardown, but Complete

All advice I give is only valid until an expert corrects me.
Don R
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Re: CB750 K2- Much Better

#187

Post by Don R »

There has been a rash of bad condensers recently there has been some conversation on sohc4. Most seem to have the same origin so good luck. Edit, I checked there, the consensus is the TEC brand condenser is better than Diachi. Diachi has a propeller logo. Some guys gave up and went to electronic or points with hondaman transistor ign.
78 GL 1000, 70 CB750 sandcast, 70 CB836 hot rod, 1124cc 750 dragbike resto project.
You don't need a weatherman to know which way the wind blows.
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Lucien Harpress
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Re: CB750 K2- Much Better

#188

Post by Lucien Harpress »

Popping the new condenser on wasn't too bad. The hardest part was finding a 5.5mm socket to get the screw on the points loose. The new condenser may have tamped down on the light show a bit, but it's hard to tell. Either way, the bike didn't run any worse than it did before (which was not bad).

It was still enough to require a 1.5 hour test ride.

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Overall? Still a wonderful little bike. A bit buzzy, but no deal-breakers. There's still a bit of work to do- steering head bearings are first on the list, and I've got a small brake fluid weep at the connection where the soft line meets the hard line. I'm also not ruling out another engine pull in the distant future- the tach drive leaks like crazy, and I AM getting a line of oil around the head gasket for sure. That being said, it still leaks less than my GL1000 did, so any addressing of this is pretty far off.
1997 Valkyrie- Light Cutomization, but Too Busy Riding
1980 KZ1300- Bike's Haunted
1976 GL1000 (Yellow)- It Runs (Poorly) and Doesn't Leak (Mostly)
1974 Velosolex 3800- Better Than Walking
1972 CB750- Broke the Chain And Ate the Motor
1969 CT90- The Most Fun You Can Have on 90ccs.
1965 CA77 Dream- Needs a Full Teardown, but Complete

All advice I give is only valid until an expert corrects me.
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Re: CB750 K2- Much Better

#189

Post by Whiskerfish »

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Don R
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Re: CB750 K2- Much Better

#190

Post by Don R »

The tach seal is just a flat rubber washer, you can hook it with an o ring pick. Apparently the new head gaskets are thicker and the replacement o rings are smaller causing some oil weeping on rebuilds.
78 GL 1000, 70 CB750 sandcast, 70 CB836 hot rod, 1124cc 750 dragbike resto project.
You don't need a weatherman to know which way the wind blows.
low-side
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Re: CB750 K2- Much Better

#191

Post by low-side »

There should be an oil seal on the tach drive, but it's easy to service. A long wood screw can be used to pierce and pull it. A deep well socket drives it in. Only takes a few minutes. I think I loosened the tank on the last one I did, but I didn't pull it. You might find that the line of oil around the head goes away after you replace the seal.
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Lucien Harpress
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Re: CB750 K2- Much Better

#192

Post by Lucien Harpress »

Unfortunately the seal is brand new. Either the drive spindle got nicked, or (more likely, IMO) there's a defect in the valve cover. I can't tell for sure, but when I had the seal out it looked like there was almost some kind of casting void in the cover, past the seal.

In any case, I've got a spare valve cover- I just don't feel like pulling the motor (again) to address it quite yet. And I've heard this is a somewhat common problem anyway.
1997 Valkyrie- Light Cutomization, but Too Busy Riding
1980 KZ1300- Bike's Haunted
1976 GL1000 (Yellow)- It Runs (Poorly) and Doesn't Leak (Mostly)
1974 Velosolex 3800- Better Than Walking
1972 CB750- Broke the Chain And Ate the Motor
1969 CT90- The Most Fun You Can Have on 90ccs.
1965 CA77 Dream- Needs a Full Teardown, but Complete

All advice I give is only valid until an expert corrects me.
User avatar
Lucien Harpress
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Re: CB750 K2- Much Better

#193

Post by Lucien Harpress »

Not too much to add to this thread. Just digging it up to let everyone know it got up to the mid 50s today, and that it's super odd to have a bike I can RIDE, and not just work on.

Image
1997 Valkyrie- Light Cutomization, but Too Busy Riding
1980 KZ1300- Bike's Haunted
1976 GL1000 (Yellow)- It Runs (Poorly) and Doesn't Leak (Mostly)
1974 Velosolex 3800- Better Than Walking
1972 CB750- Broke the Chain And Ate the Motor
1969 CT90- The Most Fun You Can Have on 90ccs.
1965 CA77 Dream- Needs a Full Teardown, but Complete

All advice I give is only valid until an expert corrects me.
User avatar
desertrefugee
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SUPER BIKER!!!!
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Re: CB750 K2- Much Better

#194

Post by desertrefugee »

So.. did you ride it or just take it out for a little Sun?
- Life is not about waiting for the storms to pass. It's about learning to ride in the rain.
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Lucien Harpress
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Re: CB750 K2- Much Better

#195

Post by Lucien Harpress »

I probably did about two hours on the road. It was chilly, but I keep forgetting "single layer of jeans" isn't great when it's under like 75 degrees.
1997 Valkyrie- Light Cutomization, but Too Busy Riding
1980 KZ1300- Bike's Haunted
1976 GL1000 (Yellow)- It Runs (Poorly) and Doesn't Leak (Mostly)
1974 Velosolex 3800- Better Than Walking
1972 CB750- Broke the Chain And Ate the Motor
1969 CT90- The Most Fun You Can Have on 90ccs.
1965 CA77 Dream- Needs a Full Teardown, but Complete

All advice I give is only valid until an expert corrects me.
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