Honda CB 350 K4 | GTAMotorcycle.com

Honda CB 350 K4

Delboy

Well-known member
I know this is a bit of a long shot but I know there a few people into Cafe Racers here.

Anyone own a CB/CL 350 twin and have a manual? I'm trying to find out what the valve seat pressure is with standard valve springs.

Bitzz is usually one of the guys that knows these sorts of things.

Thanks
 
Nope
... and I don't think that you will find that info in a regular manual. I think they only list length.

Try Barb at Megacycle cam or anyone at RD spring.
 
What Bitzz said - all you'd (maybe) find in the factory manual would be valve spring free length.
What are you trying to do ?
 
Thanks Guys. Will reach out to Barb.

Trials, if i had to take a guess I would have said somewhere between 80-100 lbs as well.
 
Geesh stuff has gotten expensive, I remember when they sold the whole motorcycle new for 800$ and there was no sales tax to add.
 
Geesh stuff has gotten expensive, I remember when they sold the whole motorcycle new for 800$ and there was no sales tax to add.

How old are you?
First new bike I bought was a '74 Cr250. It was about $1500. The Cr125 was $2300.
A '73 Rd350 was about $1350.
 
And smokes were $0.45 a pack.
Don't know, I bought or passed on a lot of motorcycles but I never smoked.
... born in 1955
 
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How old are you?
First new bike I bought was a '74 Cr250. It was about $1500. The Cr125 was $2300.
A '73 Rd350 was about $1350.

First bike I rode was a CB350 in ~1968.
A new KZ750 in '77 was $1795. Upgrading to a KZ1000 cost me $100 a week later.
 
What Bitzz said - all you'd (maybe) find in the factory manual would be valve spring free length.
What are you trying to do ?

Building a race bike for some vintage events. The Class rules say OEM Valves, Springs and Camshaft with no modification to the intake tract. I have the head rebuilt but bear in mind these parts are almost 50 years old and Honda stopped making them a long time ago. I just wanted to make sure its not too out of whack. I don't want to build a valve bending, guide cracking device ;) If it was for other classes, I'd probably just throw in a set of kibblewhite guides, valves and spring, a Megacycle billet cam with a bit of porting and call it done. That would actually be kind of nice.

I was able to find a decent set of outters quite easily. The inners were more difficult and I would describe the set I ended up with as adequate

That's what I like about the VRRA in Canada. A little thought went into their rules, and although you are restricted to OEM valves, they let you use aftermarket springs
 
A new KZ750 in '77 was $1795. Upgrading to a KZ1000 cost me $100 a week later.

I often wonder, In real terms how has the price changed when you compare it to a current ZX-10r that's around $17k?

Would the new one cost more or less when you compare it to what you are making today?
 
I often wonder, In real terms how has the price changed when you compare it to a current ZX-10r that's around $17k?

Would the new one cost more or less when you compare it to what you are making today?

Wages have fallen behind. I think it would have been a little bit easier in the 70's.
 
Building a race bike for some vintage events. The Class rules say OEM Valves, Springs and Camshaft with no modification to the intake tract. I have the head rebuilt but bear in mind these parts are almost 50 years old and Honda stopped making them a long time ago. I just wanted to make sure its not too out of whack. I don't want to build a valve bending, guide cracking device ;) If it was for other classes, I'd probably just throw in a set of kibblewhite guides, valves and spring, a Megacycle billet cam with a bit of porting and call it done. That would actually be kind of nice.

I was able to find a decent set of outters quite easily. The inners were more difficult and I would describe the set I ended up with as adequate

That's what I like about the VRRA in Canada. A little thought went into their rules, and although you are restricted to OEM valves, they let you use aftermarket springs

interesting....
do you have to document the build?
photos, receipts etc?
 
You need to submit photos for Eligibility. When I raced at the VRRA in Canada and you also had to do that - i'm not sure if they do it any more or not.

You then get an eligibility number.

Its hard to see inside an engine but if someone files a protest in theory they will make you take it apart.

For me its a cheap way to get a second bike out there. The only real cost in the engine was a hone, new rings, a slipper type cam chain tensioner to replace the Honda roller one, a new cam chain and gaskets. The rest of it was all elbow grease. It was remarkably good inside for something that's 50 years old.
 
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Outer spring 62.6 - 72.0 kg @ 31mm
( 138.0-158.8 lb @ 1.22 in)
inner spring 30.5-35.1 kg @ 26mm
(67.3-77.4 lb @ 1.02 in)

pays to keep old old stuff sometime, any other numbers you need?
 

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