Classic Honda power question

[robodonkey2005]

Howdy folks, anyone here know the BHP for the following Honda CBs:

1978 400 4 F2
1973 500 4 (Euro Spec)
1973 550 4 (US import)

Thanks

I've been toying with getting back on a bike and I rather fancy one of these older models, just need to confirm the power for license etc

If they are over 33bhp (which I guess the 5's will be) is restriction of these older ones do-able?

Oh, and if the claimed BHP is close to 33bhp at time of manufacture, is it possible that the engine no longer makes that (ie get it dyno'd and get a cert that way?)

Cheers for any info.....

[black-k1]

Claimed power was above 33bhp but was optomistic and may well be down to that level now.

Check out:

http://dspace.dial.pipex.com/graham_c/Reference/r_...

http://en.wikipedia.org/wiki/Honda_CB550

http://www.sohc4.net/index.php?title=1975_Cycle:_C...

http://www.motorbike-search-engine.co.uk/classic_b...

[robodonkey2005]

Cheers for that

[Carl-H]

With any of the bikes you don't need the restrictor certificate. If you do decide to restrict (a lot of people don't as most insurance companies don't ask) take it to a dyno and get him to put a pin in the throttle at 33bhp. Certificates are not a legal requirement.

[wiliferus]

Certificates are not a legal requirement, but i think i'm right in saying if you do have a run in with the BiB its up to you to prove that it is under 33bhp, not up to them to prove it isn't, and therefore a certificate is the easiest and most hassle free way of doing that

[Carl-H]

Nope, they have to prove its over 33bhp. If it is restricted then you have nothing to worry about. My bike is listed as 40hp (so I recon I would be lucky to get 33 at the wheel anyway) and my insurance didn't even ask if its restricted. Dyno readout would be enough proof to get the police off your back even if its their job to prove its not restricted.

[Dunc B]

Never mind the power, how tall are you?
CB400 is IIRC the VFR400 of the late 70's and gets uncomfortable if you're more than about 5' 10" , lots of revs and not a lot of go.
Just a thought!

[robodonkey2005]

Fear not, I am indeed a shortar$e
One of the attractions of the older bikes seems to be that they were designed for shorter folk....

[sprinter885]

Just curious- is the 33 bhp restriction based on "at rear wheel" figures or at crank?

Also-do all manufacturers abide by same definition in their quoted figures i.e. crank or rear wheel?

[srob]

robodonkey2005 said:

Howdy folks, anyone here know the BHP for the following Honda CBs:

1978 400 4 F2
1973 500 4 (Euro Spec)
1973 550 4 (US import)

Thanks

I've been toying with getting back on a bike and I rather fancy one of these older models, just need to confirm the power for license etc

If they are over 33bhp (which I guess the 5's will be) is restriction of these older ones do-able?

Oh, and if the claimed BHP is close to 33bhp at time of manufacture, is it possible that the engine no longer makes that (ie get it dyno'd and get a cert that way?)

Cheers for any info.....

You can definately get restirctor kits for 400-4 Honda's. The mate I did my test with had one resticted. Didn't know it was a 'real' BHP rather than a listed one (we were the first year of the restictions) - would've saved us all loads of dosh!

[Carl-H]

sprinter885 said:

Just curious- is the 33 bhp restriction based on "at rear wheel" figures or at crank?

Also-do all manufacturers abide by same definition in their quoted figures i.e. crank or rear wheel?

Its not defined anywhere whether its at the wheel or crank. Manufacture homoglation (sp?) figures are measured at the crank so its probably meant to be there but do you now anywhere that can measure the power at the crank?