[bahn88]

The english seem to have an unhealthy obsession with FS1E mopeds.

Not sure that is quite right but there is a mad Honda Cub modification scene and Cubs are going for £1800 to £4000 which is more than CX’s!
[/QUOTE]
4000GBP is bout $7000...can buy you a lot of bike....here a friend bought an older low mile thruxton for $6000A.
Yup.maybe a case of ..supply and demand....and "whats the flavour of the month"?

 

[CXPHREAK]

I've been reading 'classic motorcycle mechanics' magazine for years though started just spot buying it fairly recently as it's now becoming populated by bikes I consider 'new'.

Anyway, after that digression ....

The number of articles this magazine has done on these little Yamahas gives me that impression. And the 4 billion 'readers bikes' submissions.

I do get it. My first bike was a CD125 .... and I would like another for sentimental reasons but likely can't afford to.

I still have the CB450 that I've had for near 40 years. It'll make an appearance in the phreak shed thread in due course.

 

[bahn88]

enough digression....

do you think the 450 will be a "keeper" or something you will sell after done?
As its been with you for 40 years...I'm thinkin' it a relative and a keeper....

 

[CXPHREAK]

The 450's a keeper.

Though I had a gold CB350 when I met the missus this is the one we mainly ran around on as I bought it soon after.

I have to inventory the parts I have put away for this bike as I'd been buying NOS for this bike for years until about 10 years ago. I've forgotten what is there.

I've been researching good frame paints and was hoping to find a good enamel to put through the gun but it looks like I might go with VHT chassis and roll bar paint - if I can source it as VHT supplies are a bit spotty.

 

[bahn88]

after I asked the question...keeper or not..I realized the silliness.....

those 450s were Hondas first "big bike"...are we going to get a view of the engine internals when it appears in the thread...?...if so many will find it interesting...

 

[CXPHREAK]

Yes. The engine is to be rebuilt. It doesn't need much as it's only done 4,500 miles since new but it has spent over a decade with the head off and dust and crap has got in through holes that appeared in the plastic the bottom end is wrapped in.

These engines are fairly typical K series twins except for the dohc head which is in itself unusual in using torsion bars for valve springs.

I sold another couple of CB450s in the past few years. One I rebuilt. The other I bought to rebuild but actually sold for 10 X what I paid for it exactly as I bought it. This eventually ended up with a mate of a mate who cafed it.

 

[bahn88]

yes......those valve springs are what I was referring to interested in....
often discussed even in CAR forums.....

Torsion Bar Valve Springs?

Torsion Bar Valve Springs? Car Talk

forum.miata.net

 

[CXPHREAK]

A miata forum? My son has an MX5.

This feature in these bikes gave buyers grave misgivings but the design was a good one. It must have been as the 450/500 had a lengthy model run.

They were designed around the shortcomings of coil springs in high revving motors at the time.

metallurgy and using two springs with different harmonics sort of made the matter moot at about the same time as these went to market.

I can never beleive that the english manufacturers were never afraid of the Japanese manufacturers until the release of the CB750.

They should have feared them with the 450. The CB72. The CB92. Strewth .... the cub.

BSA built a scooter {Princess?} that had the points behind the clutch meaning much of it had to be dismantled for a regular service item. This from a manufacturer who built many models of bike for military contracts and must surely have known better.

 

[bahn88]

I'd like to see the internals and a bit of how the valve clearances are set on this set up......

 

[CXPHREAK]

The valve clearances are set with eccentric shafts on the rocker pivot. Loosen the lock nut and rotate the shaft until clearance is correct. Tighten locknut.

The adjustment method itself is shared with the other K series twins.

 

[D-Fresh]

When you say torsion springs, do you mean like an overhead garage door spring or like a VW/Mopar spring?

 

[D-Fresh]

I guess the VW & Mopar are actually bars not springs?

 

[CXPHREAK]

Yes, like veedub and valiant suspension. A rod twisting as spring.

 

[D-Fresh]

Can't wait to see the pics of that valvetrain...

 

[Randall-in-Mpls]

The valve clearances are set with eccentric shafts on the rocker pivot. Loosen the lock nut and rotate the shaft until clearance is correct. Tighten locknut.

That's how the rear wheel alignment works on my car.

 

[bahn88]

The valve clearances are set with eccentric shafts on the rocker pivot. Loosen the lock nut and rotate the shaft until clearance is correct. Tighten locknut.

The adjustment method itself is shared with the other K series twins.

There is a reference in the Miata forum of these being set with the engine running....

There is some people that say they set the clearances** without afeeler gauge....and opening the inspection ports....this was alluded to it the Miata forum at #4 but also features on youtube....bush(mechanic) craft/witchcraft?

Edit: *=adjust clearances

adjusting cb450 valves - Bing video

www.bing.com

 

[D-Fresh]

wow! that's crazy! have you tried that method?

 

[murrayf]

and dont for get on a 450 one of the eccentrics is set counter rotating 3 one way one is opposite

 

[CXPHREAK]

wow! that's crazy! have you tried that method?

I've never tried it. And won't.

These bikes had cold oil supply issues to the camshaft causing premature wear. Clearances set without use of feeler gauges running at zero clearance is likely another.

Murray, I don't get you. While it's been a while since I've been into one of these motors all of the components are A and B diagonally opposed across the motor aren't they?

 

[bahn88]

I thought it might be a bit o' a "bush mechanic" approach....hence my question at #556.....I do remember tho' carbie mixture adjustments using the tacho. and looking at throttle cable engagement at each of the twin carbies as recommended by Haynes in early bike ownership. (in 1976...and a ?1971 CB250 )......

"bush mechanic" definition/description:

Bush mechanic - Wikipedia

en.wikipedia.org