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  1. C

    First bike tell me anything!

    -Just bought this bike not sure what generation frame, not sure if engine generation belongs to frame. -It is a hard tail it starts up right away (currently cold here) shifts sound a little “loose / clanky” Whats it worth, what kinda troubke shooting/ maintenance can I do (aside from the...
  2. P

    Engine swaps for Honda CB 750 SC

    Hi, New to the forum. I would really appreciate your help with this. I bought a 1982 Honda CB 750 SC. Unfortunately the engine is bad so I have to replace it. What years/models can I use? Thank you in advance, Paulie
  3. N

    Engine/Crash Guard for 1980 CB750C

    I’m having a hard time finding the compatible engine guards for the 1980 CB750 Custom bike. And a reliable retailer that can ship to/within the US. Has anyone had any luck in this department?
  4. R

    Primary chain loose. chain from crank to primary shaft CB 900F

    Hi, I have a 1982 CB 900F and I need some help with it. I had finished building the engine and everything seemed to be perfect. However, when I accelerated, the primary chain (the chain from the crank to the gearbox) slipped. I opened the gearbox and found that the chain was loose and had...
  5. R

    300 or 341

    i have a CB 750 and i was trying to determine if 300 and 341 exhaust systems interchange. i have also read that some of the aftermarket exhausts wont allow you to remove the oil filter, are they common out there? thanks and cheers from Australia
  6. R

    1972 CB 750 4 into 4

    Hi everyone, i am after an OME and or an aftermarket 4 into 4 exhaust, does anyone have a good lead i could follow to enquire after the exhaust. Much appreciated
  7. A

    81 DOHC Rebuild- anyone know what this part is

    Doing my first engine rebuild and while I was tearing down the motor, working on getting the crankcases separated (I think) I had the motor on its side and this guy fell onto my worktop. Not sure what it is our where it came from. Any thoughts?
  8. popsycle

    Physical Exam just became an autopsy!

    I have been examining the motor on a CB750K (1981) with an eye to getting it to run. It's a bike that was left in a storage locker with a license plate that expired in 2001. I found the electrics had a dead short and other apparent issues but today I did a "thumb" test and found no compression...
  9. H

    POP Yoshimura camschaft HELP.

    Need some help! I have an old yoshimura camshaft. We installed it in a Honda CB750 F2 (1978) engine, but there is no documentation for it. We can't set it. I only have the attached hard-to-understand document. Is such accurate document or data still available? Many thanks for the help! (sorry...
  10. A

    Lwr Case - Is this a crack?

    Just inspecting and saw this. Not sure if this is a crack. Nothing is visible from the inside of the case. So not sure what’s going on here if if it is any concern.
  11. A

    Main Bearing Look

    Tearing down my first engine and wanted to get some seasoned eyes on my main bearings. They look good to reuse? I am Picking up some plastigage so I know that will be the determining factor but just asking if The old ones pass the eye test.
  12. A

    New Main Bearings

    Rebuilding engine on my 81 750. I know I have seen posts on here from amc about the "hard/expensive" to get main bearings for the DOHC. On Partzilla they are $17.50 EACH. Is that accurate that I am going to shell out $180+ on main bearings? Any places you know where I can purchase them from...
  13. Terry Carter

    Not sure about the year of my bike

    Just bought a 1971 or 1972 cb750. Engine serial and frame serial come up as 1972 but was registered as a 1971. So if I wanted to purchase a whole new wiring harness would it make a difference ? Comments and opinions welcome. Thanks in advance
  14. A

    Opinions and Suggestions

    Hey all been lurking and reading a ton on here as of late. I’ll skip the long intro (another thread)and cut to it. Picked up an 81 CB750 for a few bucks with the goal of just learning about motorcycles and engines. (Zero prior experience). no real hard goals other than that. Started with an...
  15. Hondaman78

    Leaking oil from exhaust

    Ok so my 1978 Honda 750F is spraying oil from cylinder number 3 exhaust and I have no idea where it’s coming from, I thought maybe a valve seal but I’ve heard that a valve seal wouldn’t leak that much. Please help!
  16. P

    Hey Ya'll, I am getting ready to rebuild a 1970 CB-750 engine. Bottom up.

    I have the code for the crankshaft main and connecting rod bearings. And I think the case codes. Does anyone know where I can get the correct bearings? I know from hard experience that you have to match the codes. particularly on the older engines. I had the crank measured and evaluated and...
  17. J

    1971 honda cb 750 shifting problem

    My 71 cb 750 has a hard time shifting from 2nd to 3rd ,I took off the side case and the shift shaft arm has a lot of play is this normal or could that be problem thanks jerry
  18. L


    will a 1982 engine fit into a 1993 frame
  19. S

    Spark plug hole screw up

    Hey there lads, I was trying to perform a compression test but noticed that my tester loses compression fast, so I figured my litle screw in did not perform well, long story short i noticed I have a damaged thread in cilinder one. I have no idea how , because before the compression test I was...
  20. T

    Compression Test woes

    Hi. 1980 CB750 Custom Just did compression test and was surprised by the numbers. Cyl. 1 = 95 psi Cyl. 2 = 100 psi Cyl. 3 = 50 psi Cyl. 4 = 70 psi How can these be this low and bike starts and drives? Valve clearance must not have been done by previous owner and if I understand right, the...
  21. loxley007

    Cylinder head - broken flange bolts

    Hi all, i am tearing down a 1979 CB750 (RC01) engine and the person I bought it from has secured all bolts with something fairly strong. This has resulted in 4 broken flange bolts when I was removing the camshaft cap holder bolts in the cylinder head I’ve removed one of them but messed up the...
  22. J

    Acceleration problems

    Hi All Please help if you can, I have just joined the forum so apologies if this has been dealt with before. 1980 CB750F DOHC Starts easily. Has good compression. Idles well. Initial acceleration at minimal throttle is good, but as soon as you open the throttle wide. Engine stuttering and...
  23. L

    Intake cam chain play

    I noticed the intake cam chain (part #6) tightens and loosens when I manually turn the engine over. I'm aware that chains have tight spots but when this loosens up it's hits the chain guide that goes overtop (part #14). If I adjust the cam chain tensioner once the engine is idling (part #11)...
  24. B

    valve spring replacement

    having valve job done on an all original, stock 81 custom with 47,000 mi. considering replacing valve springs and having trouble finding OEM replacements.I haven't measured the original springs. I assume they would be tiered after 42 years. APE. VS900H heavy duty racing valve springs are an...
  25. B

    Stuck sparkplugs

    Hello, I've always loved these bikes and finally found a 1975 cb750 I'm working to get running by summer. I will probably be looking on here a fair bit the next few months trying to figure this thing out. The bike looks amazing and had been garage stored since the mid 80s. My first problem is...
  26. P

    Oil Lines

    I am rebuilding my 1970 CB-750 engine and need 2 new oil lines. I can get the oil hose. But I need the steel Ferrules to attach the hose to the fittings. I have found some brass ones. But they are light. And I am sure that they will corrode.
  27. R

    Valve depressor tool

    I want to buy a good tool for adjusting the valves on my DOHC CB750k. Is the OEM Honda two piece tool (07964-422000A) better to buy or the MotionPro "c-shaped" one?
  28. R

    1980 SuperSport Reduction Gear, Starter

    Recently bought a 1980 750F, sitting for 15 years ! The starter is slipping, did new springs, full cleanup and its worse than before, will not engage at all. I just Noticed the big gear wobbles, is there a cure for this? replacement gear? shim?
  29. G

    Different head gasket for 1970 cb750

    I have been redoing the motor on my 1970 Honda CB 750. I’m just noticing the head gasket is a little bit different and not sure if I should be using a different one? There is one hall on the front part of their head gasket but no hole there I think it would be OK but I am not sure. I will send a...
  30. G

    1970 honda 750 Low compression

    my 1970 honda has not run since 1982,so i started to give the bike a compression test,and the 2 outside cylinders were 50 lbs on one side and 100 on the other side.After taking the tappet covers off on the inside cylinders I discovered the nut and tappet are missing on the intake valve on...