Author Topic: Cam chain  (Read 1062 times)

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Offline emlupi

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Cam chain
« on: September 12, 2024, 10:40:28 AM »
Hello all,
I am currently working on a CB350 twin engine for vintage bike racing. I am planning on using a KA slipper type cam chain tensioner so I’m trying to locate a Tsubaki flat link cam chain (BF05M-94). The reason I’m posting here is because I understand that the SOHC 4 750 uses the same cam chain. I assume they’re discontinued because these things have become impossible to locate.
Barring that, what cam chain and tensioner arrangement are you using in your race engines with the 750? Any help or advice is appreciated, thanks.

Offline Oddjob

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Re: Cam chain
« Reply #1 on: September 12, 2024, 10:59:58 AM »
What about the DID 219FTH chain. Or something similar if the pitch is wrong.

Offline emlupi

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Re: Cam chain
« Reply #2 on: September 12, 2024, 11:02:13 AM »
I looked at that as well but didn’t see one for our application. Perhaps I wasn’t looking in the right place? If you know of a source I would be much obliged, thanks

Offline Oddjob

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Re: Cam chain
« Reply #3 on: September 12, 2024, 11:05:13 AM »
If the chain is the same as the 750 then it’s the 219FTH you need. The problem is finding one the correct length, do you know how many links you need?

Offline emlupi

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Re: Cam chain
« Reply #4 on: September 12, 2024, 11:27:58 AM »
94 links, which is the same as the SOHC 750. So far I haven’t been able to locate one. When you consider that between these two models Honda produced about a half million units, it’s a little hard to believe that nobody is making these parts available.
« Last Edit: September 12, 2024, 11:30:04 AM by emlupi »

Offline PeWe

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CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline RAFster122s

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Re: Cam chain
« Reply #6 on: September 12, 2024, 09:41:55 PM »
David- back in the desert SW!

Offline teebee67

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Re: Cam chain
« Reply #7 on: September 13, 2024, 01:59:57 AM »
I raced K4 350's for 30 years plus and have raced a CB750. There is absolutely nothing wrong with the standard cam chain tensioner on the 350's providing they are set up correctly. The trick is to adjust the tension at the "sweet spot". Set the valve clearances a little wide and rotate engine until all the valve springs are not under tension, then set the chain tension.
I'm only old on the outside.

Offline emlupi

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Re: Cam chain
« Reply #8 on: September 13, 2024, 03:49:09 AM »
Thanks everyone, all good information.
Rafster, that Tsubaki chain is not the “F” flat link type, but thanks for the heads up.

Teebee, thanks for the advice. Much appreciated. I think the main knock on the stock tensioner is that the rollers are not durable under constant high rpm usage. The class I am going to be running is a spec class for mostly stock engines, very limited modifications allowed. I would assume that a refreshed factory tensioner, properly adjusted, would be adequate for this type of racing? Would it help to use the Capellini type with the roller bearings and a flat link chain? Your thoughts on this are appreciated.

Offline teebee67

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Re: Cam chain
« Reply #9 on: September 14, 2024, 01:38:55 AM »
I know a lot of people run either the steel roller or the slipper type tensioners but I find the standard tensioner is more than up to the job. Believe me my bikes were revved hard. I did try a steel tensioner once but found steel shavings in the oil so never used it again.
I'm only old on the outside.

Offline turboguzzi

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Re: Cam chain
« Reply #10 on: September 15, 2024, 02:29:20 AM »
oil cooled GSXR's have flat link chains, used those chains in my CB500 racer if thats any help