Primary Chain

[bikeymikey748]

‘Morning folks.
I’ll be on the north side of 100,000km. by the time the snows come again.
Planning on replacing my cam chains, valve seals (used aftermarket ones when I did my build, looking at viton replacements), as well as crank and con rod bearings.
I was wondering what the consensus was regarding primary chains. Specifically, should I consider replacing mine when the motor is open? There’s no unusual noise, and no markings on the oil spray bar. Are they long-lived?

[NobleHops]

Mike, I personally think you’ll find you need a large cam chain tensioner before you need crank or rod bearings, but you’ll know when the plastigauge is employed.

[bikeymikey748]

Thanks for chiming in Nils. When I did my build I replaced my ‘A’ tensioner with a new (reconditioned) one, is that what you’re referring to? I know the adjuster for the ‘B’ chain is pretty much maxed out though . As that tensioner was replaced with a new OEM one during the build as well I’m guessing the chain is roached. Figured the crank and rod bearings, as you mentioned, will get a check with plastigauge but I would expect they might need a refresh at this point, no? I’m into the upper range of my revs on a fairly regular basis and between that and looking down the barrel of another looming Canadian winter figured it would be a perfect time to dive into the motor and secure some peace of mind for next few years. I had fitted aftermarket valve guide oil seals and plan on replacing them with viton bits. I’ll McGyver a tool to do them without removing the head. Scored some oversized Oldham couplings from Bert at Six Center too. Looking forward to seeing how well they work out.

[NobleHops]

Personally I would not replace those bearings wholesale if they measure in spec and there's no evidence of smearing or transfer of the bearing material.

[bikeymikey748]

“Personally I would not replace those bearings wholesale if they measure in spec and there's no evidence of smearing or transfer of the bearing material.”.
Absolutely. I just HAVE to have a look though

[bobcat]

There would be no question in my mind about replacing the primary chain while you have the motor
that far apart. With that many miles and "upper RPM range" frequent use and maxed out cam chains,
why take the chance. There is no unusual noise until suddenly there IS ! It will do a lot more damage
than just a broken chain. My 2 cents..

...and don't skimp on quality by buying the cheapest one. Suggest Borg Warner (Morse).

[bikeymikey748]

I hope to be updating my old project thread in the near future. For the moment, after opening the motor as well as cleaning/measuring, my three chains are all in need of replacement, and crank/rod bearings are looking tired. No need of checking with plastiguage, wear is obvious and advanced. All journals are in spec. Once I removed the springs, the valves dropped out of the head. There was zero tension left on the guide seals.
Hold my beer…I’m goin’ in.

[daves79x]

I'm sure you've seen JR's posts here about Brent Hyde's new cam chain tensioners. Whether that's something you'd consider or not, I would for sure get his cam chains and primary chain. They are of superior quality to anything you can buy on this continent.

Dave

[bikeymikey748]

I'm sure you've seen JR's posts here about Brent Hyde's new cam chain tensioners. Whether that's something you'd consider or not, I would for sure get his cam chains and primary chain. They are of superior quality to anything you can buy on this continent.

Thanks Dave, love Brent’s offerings, but price-wise, they are out of my reach.
I picked up both cam chains from Borg Warner. My research says they are of great quality. Would you agree?
The primary chain is a pattern replacement from David Silver. Again, hopefully of good quality.

[hcbx1047]

Where did you source the chains?

[bikeymikey748]

Where did you source the chains?

I got the cam chains from these fine Canadian suppliers:
https://www.partsnmore.com/parts/honda ... %5D=custom
Parts N More
79 Linton Ave,
Stratford, ON N5A 2S3
Canada

The primary is a Japanese-made aftermarket piece from:
https://www.davidsilverspares.com/
They had the best price I could find and quality I was looking for.
Are you thinking of swapping yours out ?

[hcbx1047]

Yes, I have my motor completely broke apart right now, so putting in all new chains. I see Partsnmore has a primary chain too, but no info on its origins. Did that turn you off from buying from them?

[bikeymikey748]

Yes, I have my motor completely broke apart right now, so putting in all new chains. I see Partsnmore has a primary chain too, but no info on its origins. Did that turn you off from buying from them?

To be honest, I must have scrolled right past that one ‍
Seeing as the cam chains are made in Japan from a well-respected manufacturer it just may be the primary follows suit.
Maybe shoot them an e-mail to get more info. Price is attractive as well.