CB650 Cam in a CB550

This swap always interested me for the power bump but I never found any good comparison info about it so I was skeptical that it was possible without major modification. I successfully completed the swap and it was very straight forward but you will need to some additional parts to do it.

Here’s all the differences I found when swapping my CB550 cam for a CB650 cam. Follow the manual for the proper process of changing a cam.

Cb550CamSwap-1

Parts Needed:
79-82 CB650 cam
79-82 Tach drive
CB650 or CB750 Tachometer

Cb550CamSwap-2

The CB650 has a hy-vo cam chain so the cam sprocket will NOT work with the CB550’s normal cam chain. The CB550 cam sprocket and sprocket bolts fit on the 650 cam.
CB650 (left) / CB550 (right)

Cb550CamSwap-4
Cb550CamSwap-3

The cam markings are very similiar between the two.
CB650 (left) / CB550 (right)

Cb550CamSwap-6

CB650 (top) / CB550 (bottom)

Cb550CamSwap-5

Notice the slighly different pitch for the tach drives.
CB650 (bottom) / CB550 (top)

Cb550CamSwap-7

Tach drive pitch is slightly different.
CB650 (right) / CB550 (left)

Cb550CamSwap-8
Cb550CamSwap-9

Review:
I’ve been running the 650 cam for a few weeks now and have also changed from the air box to Uni pod filters. The power difference is not crazy but it is a nice even increase. The most noticable is on the top end, the bike wants to continue pulling strong 80-100mph. Previously it was a slower acceleration in that range.

11 responses to “CB650 Cam in a CB550”

  1. brad says:

    so whens the 650 vs 550 race happening? Ed’s getting a little slow these days. I think you can take him

  2. D car says:

    My sportster would smoke eds bikes. It’s got 4 cams!

  3. MIke says:

    Ed is still a little sore from his last race when I made him look silly. I bet his car is fast though.

  4. Adam says:

    Mike, did you race him on the sportster? 1200 or 883?

  5. MIke says:

    Adam- yea 1200. but his “jetting was off” haha.

  6. Ed says:

    Damn… Race all y’all

  7. David says:

    are you using stock carbs? F or K? I’m currently rebuilding the top end of a CB550F supersport and considering this mod along with carb mods or the pricey CR carbs

  8. Adam says:

    Hi David, I am using the stock carbs from my 550K. I have them setup with Uni filters, stock needle, 115 main, 40 slow. Still tweaking some fine tuning but it is pretty spot on. 650 cam was absolutely worth doing.

  9. Maxime Bimar says:

    Thanks for the report. Regards from Denmark.

  10. MDNMX says:

    What year is 650 is the cam off of?

  11. william simon says:

    Just a 2cents worth observation here-WHY did you ditch the std.airbox??Honda designed those for a very clear reason.You benefit drastically by having the ‘passive air space’in the box,free of any excessive movement or turbulence.At one time long ago,I raced a CB400F in AAMRR-the airbox was retained,and
    no filter at all,just sealing the halves w/silicone.After some jetting work,and a less restrictive exhaust(as well as slotting the cam sprocket And DEGREEING the timing-advanced by a couple of degrees to increase slight overlap),the dyno revealed a gain of at least 4-5 hp,if memory serves correctly.And this was with a dead stock production motor.The problem that gets everyone at some point with a mild engine,and individual filters,is like the older tuner remarked,”They are exposed to so much air that they don’t get any”.It rings true in so many cases.If you are running an Extremely Built engine=read=$$$,High Comp.pistons,Radical camshaft,bigger valves,porting work,lightened and balanced crankshaft,et.al.,THEN you will have such a strong intake phase it will warrant either separate elements,or tuned intake horns(aka velocity stacks).The CB650 cam route I have taken as well,but-Degreeing the timing makes ALL the difference.Just recently I installed a NOS Weber street grind #58a into a friends’s
    CB550F,but still,it was Degreed In.Mostly similar(mid range) to the 650 cam,but a good bit more power due to more duration.And if replacing the std.air cleaner,the smart money is the K&N product.I don’t know if the OEM drop in is available for the500/550 now,but it’s an excellent filter.Best of luck to all of you out there.

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