Topic: Cam options for cb500 650???

[Calisoul]

Hey everyone!
I've got the head off of my 73 cb500k. in the process of porting and re-ringing. I basically just need to pop it back in. I figured while I was in there I would look into a cam upgrade.

I've heard that a 650 cam would give me some extra HP and is an easy swap. Has anyone done this?
These are my questions:
Will this work?
what CB650 years/ models will work?
what needs to be done besides just popping it in there?
Will this actually give me more power?

Thanks for any help guy

[calj737]

It will work. It is easy. There's a cam and tach gear (required) for sale by HellRaiser on the Parts For Sale section. You need the cam gear because the ratio differs from your 500/550. It will add some oomph to your stock motor.

Reuse your stock cam sprocket and chain.

[Bailgang]

A 650 cam will definitely wake your 500 up however it's been a popular swap and 650 cams are getting harder to find and more expensive because sellers know they are popular with the 500/550 owners. You can use the 650 cam as it is however your tach won't be accurate because the 500/550 tachs have a different ratio than the 650 so you will need the tach drive from a 650 as well as either a 650 or 750 tach. You're also rolling the dice purchasing a used cam because it may already be severely worn.

I dropped a 650 cam in my 550 and it did wake it up especially at 6k and higher rpm however if I were to do it again I'd get a new cam from say Web cams, they're not cheap but once I added up the cost of finding a good used 650 cam, purchasing the 650 tach drive and another tach when added all up I didn't save all that much. On the other hand if I had purchased a new cam from web cams the cam itself would already be for a 500/550 so there wouldn't have been a need for the 650 tach or tach drive.

[calj737]

Bailgang - aren't WebCams hardwelded? If so, you'd need to replace your rockers too with hardwelded units... That certainly exceeds the price of a cam gear and tach gauge. I agree with your perspective about used cams, I won't ever buy another after getting hosed by a seller previously. And I certainly would only buy a used cam if they sold the corresponding rockers for that cam with the purchase.

But many do, and many are pleased with the results...

[Bailgang]

Bailgang - aren't WebCams hardwelded? If so, you'd need to replace your rockers too with hardwelded units... That certainly exceeds the price of a cam gear and tach gauge. I agree with your perspective about used cams, I won't ever buy another after getting hosed by a seller previously. And I certainly would only buy a used cam if they sold the corresponding rockers for that cam with the purchase.

But many do, and many are pleased with the results...

I know they'll take your existing cam, hardweld it then regrind it but I wasn't aware that hardwelded rockers would be needed as well. That's a good point that I was unaware of.

[Tews19]

Hellraiserxl has another 650 cam for sale. PM him.

[SOHC4 Cafe Racer Fan]

Gone!

[Tews19]

He has another that he is selling for 140 iirc.

[Calisoul]

So does every model and year of the 650 work?
I thought about the cam being worn but if the seller has any kind of warranty or exchange I think it would be worth the $100/$150.

Thanks for the suggestions guys!

[Tews19]

Last post, do you mean you think a 500 cam that you have is worth 100/150? If that is what you are asking..... Um no. No one offers warranties. No much possible install issues on the buyer if they somehow messed up installation

[mrfish2]

So does every model and year of the 650 work?
I thought about the cam being worn but if the seller has any kind of warranty or exchange I think it would be worth the $100/$150.

Thanks for the suggestions guys!

The only cams that work are from 79 to 82 CB650's, which are SOHC. In 83 Honda switched the 650 over to DOHC.

[SOHC4 Cafe Racer Fan]

Be careful to check the condition of the lobes on the camshaft for pitting and excessive wear.