1979, 1980, 1981 Honda CB750 4 Exhaust Cam, Exhaust Sprocket and Timing Chains installation tips/tri

Hey, Friends!
If you’re here, it’s because, like me, there is jack squat out there for helpful info on the late 70s, early 80s Honda DOHC engines. Especially videos that are decent quality and clearly explained. I’m hopefully going to fix that.
This video is intended to give some helpful advice for those of us who don’t have professional knowledge or experience with the late 70s and early 80s DOHC Honda 4 motor.
The engine you see in the video is out of a 1981 Honda CB750c. I am giving you an overview of tips and tricks that you may find helpful. This is definitely not going to help everyone in every situation, so you may need to take my advice and tweak it or adjust it to suit you. Go for it.
I followed the shop manual and other manuals (Clymer, Haynes) to the letter and still found installation to be insane. The pictures aren’t usually clear and even step by step, parts of cylinder head assembly and disassembly can be very tricky. I learned this the hard way. I want to make sure you don’t have to.
I finally figured out some tricks. I don’t want you to struggle like I did.
If any part of this video is unclear, please leave me a comment below and I’ll do my best to clear it up!
Big shout out to Taylor at ClassicOctane (please visit his channel) and Tim on Tim2Wheels for helping me out whether they knew it or not. Also, my guy down under at CafeRacerGarage-check him out!
#Honda #Cafe #Caferacer #Brat #Custom #Rebuild #DIY #Exhaust #ExhaustCam #Timing and other hashtag nonsense. 👍🏼

[@abdulfayez6897]

This is really intimidating! I’ve spent 4 days in my garage trying to fit the cam sprocket into the tap. I dropped the screw inside the engine so I had to disassemble and go back to square one! So the secret is to install A&E cam bearings then go from there! I’ll try it right away :)) Thank you so much

[@bt5843]

Wish I saw this video yesterday!!! Fortunately I managed to get everything align. Note the exhaust cam gear has a large opening and a small opening on either side, the key is to make sure the large opening is aimed towards the front of the engine

[@koozizzel]

I tried this. It worked really well.

[@ifihadaboat85]

Awesome, my man. Glad to hear it!

[@Adm7869]

Super helpful bud ! Thank you for this !

[@user-yf9hg1eq1u]

Can you show a more detailed picture of setting the cam timing marks with the crank timing marks so I know the timing chain and gears are accurate in stalled.

[@allanbarry4149]

been trying to figure this out forever! I had the thought to do A and E but didn't trust myself enough and didn't want to cause any damage! got frustrated, came here and what do you know...A and E. I'll do this asap. theres really nothing on these engines, thanks for the video!

[@Adm7869]

After advancing the timing mark pass T, remove the sprocket, loosen cam bolts. Allow the cam to seat comfortably , do you adjust the sprocket and the chain to allow the holes to align with the new cam position ?

[@Cloverofiron]

Fantastic explanation, going to try this in a few mins. Question I do have though. For the dowel pins there is one that is longer than all others, which hole does this one go in?

[@ifihadaboat85]

Hey! Thanks so much! I believe it goes in the tachometer bearing cap.

[@Cloverofiron]

@@ifihadaboat85 That it did! Thanks! So I did the timing yesterday as well and for the end notches, you just have to have the top of the valves line up inside the notches correct?

[@ifihadaboat85]

Cloverofiron you have to make sure the notches are level with the surface of the cylinder head when your exhaust cam lobes are pointed toward the #1 cylinder spark plug

[@rocket625]

can you do one of these on the clutch i just go done with the cams

[@korky7775]

My Honda CB550 four K3 had a leaking head gasket but to be honest i had no trouble re-building the engine...

[@ifihadaboat85]

Single overhead cam helps with that. 👍🏼

[@korky7775]

@@ifihadaboat85 you know i'd forgot why it was so easy mind it was back in the 70's ...

[@allanbarry4149]

ok. I got my punch marks and notches perfectly level with the head, on the first try. I gave it a chance to spring back, then tightened again. no movement. im level and at TDC with 1 and 4. success so soon made me think I did something wrong! any thoughts?

[@bishboi3629]

Same result here!

[@lehoom]

Punch marks don`t align perfectly because of the timing chain stretch usually. More stretched, more misalignment. That`s how you can tell if the chain is worn. But what we see on your video is not a big misalignment. I`ve seen worse on many bikes I worked on in my life. Also, different thickness cylinder base and/or head gasket, will alter the puch makrs alignment. I`ve been working on bikes for 10+ years to earn living and I`ve never seen an engine with perfectly aligned marks on chain driven type cams. never. Even if all parts were new.

[@stevenfarrell7234]

This didn't work for me

[@ifihadaboat85]

Sorry to hear that, man. This is the only way I could find for it to work for me. Don’t lose hope. It’s possible to do. There were several times I had to walk away from it and come back.

[@stevenfarrell7234]

@@ifihadaboat85 I machined some plates with tabs that engage the notches on the end of the cams and lock them in place. Haven't tried it yet tho.

[@finnhermansen2177]

I never saw any trouble when rebuilding my 1100. As long as the cam marks are aligned, there is no way possible to get the exhaust sprocket wrong. The holes in the sprocket will have to match with the holes in the cam..