Hey folks - I just inherited a 1981 CB750C (as identified on the steering head tube). It has a SOHC motor. I'm confused. Can someone help me understand what I've inherited? I thought all CB750 bikes > '79 were DOHC models? Thanks in-advance for any advice; happy to attach some pics to further clarify...
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Identifying my CB750C with SOHC motor
- Thread starter Benjo
- Start date
Why do you think it is an 81?
Yup. And to me, everything about that bike screens 78 or earlier. I wouldn't be surprised if someone put that 1981 frame sticker on it to get it titled and registered.
On a second look, the side covers don't really fit, and that frame might be a DOHC frame. Man, maybe somebody took some 78 parts and put them on that bike.
On a second look, the side covers don't really fit, and that frame might be a DOHC frame. Man, maybe somebody took some 78 parts and put them on that bike.
Weird, right? Has anyone tried to drop an SOHC motor into a newer frame? I'm new to this, so unsure of compatibilities.
The bike seems to have newer components, e.g. triple brake discs. I guess I can take the motor serial # and somehow use that to get the correct motor parts.
This will be a cool adventure, methinks. Any advice and warnings ars welcome!
Thanks for your feedback, brettp.
The bike seems to have newer components, e.g. triple brake discs. I guess I can take the motor serial # and somehow use that to get the correct motor parts.
This will be a cool adventure, methinks. Any advice and warnings ars welcome!
Thanks for your feedback, brettp.
take the seat and tank off so we can look at the frame, it will be easy to tell if its a sohc frame by the tubes under the tank. will be easy to see if there has been any modifications done. Also what is the engine serial number.... The frame serial number should also be stamp into the neck, normally on the other side of the neck opposite the riveted tag.
Ya that's an '81 frame or part of one mixed with a '75-78 CB750F
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Trouble is, was the CB750F stolen and all the parts mixed with an 81? It even has the "F" instruments. Is the bike registered as an '81? As stated look for the serial number stamped into the head stock. It should match the registration for the bike.
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Hey folks - thanks for all the great info and suggestions! Hopefully I can get to more investigation this weekend. As I mentioned, this project is going to take a while given my availability. And, what a great resource this forum is - thanks again!
Hisvett
CB750 Enthusiast
The Tach is from a DOHC motor; red line is 9500 Vs SOHC at 8500. Looks to me like someone slipped an early motor into a late frame.....check the engine numbers, you can tell the production year from the first 4 or 6 didgets. Everything else looks like a standard CB750C.
Look closer. Most of the bike is a '75 to '78 CB750F. It might be a '81 frame or part of one, but most of the bike is a SOHC F model.
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Hisvett
CB750 Enthusiast
Spend a few hours going through this link.....http://www.honda750expert.com/ Again, your check motor numbers with the link. Good luck.
Hisvett
CB750 Enthusiast
This set might be for sale on FleaBay listed as early build but not really. Many of the resale people don't have any idea what they are selling. I've seen the same set listed as fitting K0 to K8....well, it might fit but it's not correct.
Here is a pic of MY box stock '78; I also have a '77 with the same red line.
If you have a '77 and '78 then you should be able to recognize how much of his bike has been put together by SOHC bike parts. What you think about the tach doesn't change the fact that his bike is mostly made out of SOHC parts. Ray Charles could figure that out.
Hisvett
CB750 Enthusiast
This from Google search, looks like they pumped up the "F" motor to 73HP (brain fart, I knew that) and bumped the Red Line 1K. Just a guess here, someone switched frame VIN tags, perhaps once a stolen bike? Sometime the orginal records will also have the engine number listed with VIN tag. A quick call to the local LEO Dept might answer that.
Home > Moto > HONDA > CB > HONDA CB750 F2 (1977-1979)
Dragos Gheran , Florin Profir
Segment: Naked / Road
Production years: 1977, 1978, 1979
The Honda 750 was the first of the new range of superbikes when it was announced back in 1969, and even its rival, the earlier announced Triumph Trident had one less cylinder than the Japanese bike's four.
The Honda motorcycle was developed from its initial K guise until 1978 and was available in K7 form, but the bike's performance was dissolved when the powerplant was modified to suit pollution regulations.
To meet the evergrowing competition, Honda announced a Super Sport F1 version that featured a sportier look, while the F2 model was a different story, with a completely revised engine that was hoped to stick to the customers until Honda's sixteen-valve twin-cam range was ready to enter the market.
While the engine was not as sophisticated as other Japanese fours, the powerplant still provided smooth power that pushed the bike to a top speed of 201 kph (125 mph), while the original Honda 750 was the first bike that featured standard brake discs, and since that time, every manufacturer adopted them.
As for performance, the 1978 Honda CB750 F2 had its soul brought to life by a 736cc four-stroke four-cylinder air-cooled engine that delivered an output power of 73 hp with maximum strength at 9,500 rpm and 63 Nm (46 lb-ft) of torque available at 7,500 rpm.
For suspension, the bike packed a telehydraulic fork on the front and dual shock absorbers with five-way spring preload adjustability on the rear.
As for braking performance, the F2 featured two 276 mm discs squeezed by a couple of hydraulic calipers on the front wheel and a 296 mm disc with a hydraulic caliper on the rear wheel.
Home > Moto > HONDA > CB > HONDA CB750 F2 (1977-1979)
HONDA CB750 F2 (1977-1979)Specs, Performance & Photos
Updated: 11 March 2023 • Maintained by:Dragos Gheran , Florin Profir
Segment: Naked / Road
Production years: 1977, 1978, 1979
The Honda 750 was the first of the new range of superbikes when it was announced back in 1969, and even its rival, the earlier announced Triumph Trident had one less cylinder than the Japanese bike's four.
The Honda motorcycle was developed from its initial K guise until 1978 and was available in K7 form, but the bike's performance was dissolved when the powerplant was modified to suit pollution regulations.
To meet the evergrowing competition, Honda announced a Super Sport F1 version that featured a sportier look, while the F2 model was a different story, with a completely revised engine that was hoped to stick to the customers until Honda's sixteen-valve twin-cam range was ready to enter the market.
While the engine was not as sophisticated as other Japanese fours, the powerplant still provided smooth power that pushed the bike to a top speed of 201 kph (125 mph), while the original Honda 750 was the first bike that featured standard brake discs, and since that time, every manufacturer adopted them.
As for performance, the 1978 Honda CB750 F2 had its soul brought to life by a 736cc four-stroke four-cylinder air-cooled engine that delivered an output power of 73 hp with maximum strength at 9,500 rpm and 63 Nm (46 lb-ft) of torque available at 7,500 rpm.
For suspension, the bike packed a telehydraulic fork on the front and dual shock absorbers with five-way spring preload adjustability on the rear.
As for braking performance, the F2 featured two 276 mm discs squeezed by a couple of hydraulic calipers on the front wheel and a 296 mm disc with a hydraulic caliper on the rear wheel.
What you are saying has already been brought up.
Hisvett
CB750 Enthusiast
So I seconed that opinion is what your saying....
So you are agreeing with me know? What happened to you trying to discredit me?
I got a chance to clean and do a little more inspection. Here's the stamp on the left side of the frame head tube:
and here's the engine stamp:
Was there really a CB750E ? Do I have a very strange compilation of bike parts?
and here's the engine stamp:
Was there really a CB750E ? Do I have a very strange compilation of bike parts?
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