CL 450 Timing Chain

[exeric]

I am going through the motor for my '66 Honda 450. I second guessed myself about the timing chain, and succumbed to people saying the timing change should be replaced. I got a new Japanese made chain, and it is way too tight, and it has made timing the cams, and crank difficult. . . Is this common with a new chain? I have another master link and wonder if I should put that in to give the chain more slack. . . I welcome comments.

[chuckthebeatertruck]

I am going through the motor for my '66 Honda 450. I second guessed myself about the timing chain, and succumbed to people saying the timing change should be replaced. I got a new Japanese made chain, and it is way too tight, and it has made timing the cams, and crank difficult. . . Is this common with a new chain? I have another master link and wonder if I should put that in to give the chain more slack. . . I welcome comments.

I've only done one of these so my "experience" is highly suspect . . .but I don't recall it being too tight -- in fact, the opposite. It was awfully slack until I released the tensioner.

So, I'd start by doing two things:
1) laying the chains side by side and making sure you indeed have the same number of links
2) making sure the tensioner is truly out of the way.

Barring that, I'd probably try a different chain from a different supplier before I'd double up on master links. Whilst I've done that on drive chains several times; I've never been brave enough to try it on a cam chain.

Sorry I can't be of more assistance. My crusty old 500 didn't put up a fight :-)

[exeric]

I appreciate the information, Chuck. This chain adventure is getting expensive as the new chain was $40, and each master link is $10, so I'm now into this (clear conscience) simple maintenance deal for $60. You have convinced me that I probably got screwed on the chain, despite that it was from a Japanese manufacturer. I think I am going to go to a 450 specialist, and buy one of their more expensive chains, which I will expect a guarantee on. . . . Geeze, I hate having a conscience

[Steve Swan]

Eric, i am sorry i have not chimed in until now, not sure i can be of much help, i worked as a mechanic for 3 years at our local mom and pop shop that operated from 1987 til 2014. Their primary specialty was working on pre-1990 bikes and most often stuff from the mid-60's through the late 80's. Anytime we replaced a cam chain, we always used and endless chain, Ray (the owner) had seen too many master link failures to not use an endless chain. He had a special tool that put a divot in each pin that held the connecting link; the divot was of course just enough so the link would not come off and more importantly not so great that the links could not move freely. i assume you have a workshop manual, if you don't there should be one on line for your year that you can download or certainly info designating the number of pins in the chain. We considered the cam chain as the heart of the motor, crucial to holding ignition timing and avoiding chain failure. any old Japanese bike with undocumented history, the timing chain should be replaced. with your machinist skills, i would think you would have no problem making up a simple tool to put the divot in each pin after the connecting link is installed. a new timing chain should be slack so you can get valve timing correct; Honda's usually go my marks on the cam sprocket aligning with a certain casting area of the head, i know Z1's go by the number of pins and marks. the 4's are not as hard on the cam chain as the twins, the smaller displacement units required a lot more rev'ing and shifting and the cam chain lengthening could be expected. hope this helps.

[exeric]

Thanks for the comment, and advice, Steve. I have genuine Honda master links which are simple links with a small hole drilled in the pins. Their intended use is to be 'splayed' with a special tool that will 'mushroom' out and make a permanent link. I did make a tool that can properly 'break' the chain, and also splay the pin to make it a permanent link. The real problem is; how was this Japanese chain I bought on ebay made to fit the many sprockets in the drive train, but now be too short?

I assume the original chain stretched over the years, but he chain tensioner did it's job keeping the cams, and crank in time. The new chain is so damn tight, I'm afraid it will wear out the cam bushings, and the chain tensioner is just a redundant appendix to the system. So, how do I know a new chain is going to work? Obviously, the mathematics of collective inaccuracy in the links is going to have a profound effect on the chain fit. I really hate this kind of ****, but as our civilization becomes more sophisticated, it seems that old world craftsmanship, and integrity is going down the drain, in favor of a cheap profit. . . And yes, I think socialists would be even worse Needless to say, I am frustrated.

[Steve Swan]

Eric, without the cam chain tensioner installed, the chain should not be tight at all. with the cam chain tensioner installed and adjusted, it will feel tight and of course there will be no whip, flapping, etc.

i am assuming this tight replacement chain is the same number of links/pins as the original? was the replacement chain you bought specifically for the CB450 or was it a "fits other models?"

EK and DID are cam chain brands we used in the shop. i am assuming you have uploaded or have a hard copy parts book. doing a brief internet search, the cam chain pn is 14401-283-003. i have 305 super hawk books, but never been inside a 450, so i don't know if some part is not aligned or... did you have the head off? as i said, i don't know anything about 3450's, but typical for Honda, cyl.head removal to replace the cam chain is not necessary.

if the chain is the same number of link there is either something else, as you say, pin to pin length is not same as factory chain or else the chain is hanging up on the lower sprocket or is not where it is supposed to travel....?

in my CB750 daze, i dealt with and know this seller "jtmarks77" is reliable, his prices are high but what he sells is what the book calls for. you can contact him directly and purchase outside of ebay and get a little bit better price or at least that's the way he used to deal. https://www.ebay.com/itm/Honda-NOS-C...ss!80526!US!-1

[aumick10]

Eric,
In another life I worked on many Japanese bikes, in shops and for myself.
As far as cam chains go, they can be split into two categories. The chain is inside the crank throws or outside. The outside chains are easy to change as they sit on the end of the motor and access is easy.

Your 450 is an inside chain. The cam can be taken out in the frame without breaking the chain. If you want to replace it with an endless chain as per factory, the crankshaft needs to come out, ie, split the cases.

The chain can be split in frame and used to pull a new chain through.
When to talk about a master link, do you mean a link with a clip like a rear chain, or a riveted link.
I have never used a cam chain with a clip on a master link, although I have seen them. If the clip comes off, you can lose the whole motor.
The correct way is to use a riveted master link with the correct riveting tool. Thinking back, it is not possible to get a riveting tool to the chain on a 450 without great difficulty.

A common fault that shows up as a loose cam chain is the front and rear chain guides wear. These are steel backed rubber coated guides that the chain runs against.
They are located inside the cylinders and run from the top crankcase to inside the head. The rear guide is flexed by the cam chain tensioner to adjust the chain.
The only way to replace these is to pull the head.

When working on these, it is common for the chain to bunch up on the crank gear and loose some length.
If you have already pulled the chain, occasionally the chain guides will move out of their pockets in the top case, which could make the chain tight. This is almost impossible to see and usually done by feel.

These 450's were fun to ride and revved like hell.
Good luck.
Mick

[exeric]

I've repeatedly checked the chain path, and all is well there. The 450 chain has to be broken to thread through all the sprockets and guides as the head, and cylinder have no open paths for an un-broken chain. The Honda links have been no problem, and the tool I made for splaying the link pins has worked very well. I made it to work in the close quarters of the cam openings. I think I'm going check out the link Steve posted, and perhaps a few other 450 specialists and talk to someone on the phone. My plan at this point is to park the Honda project, and start putting my '51 Harley back together Thanks to everyone that took the time to try and help this flailing Honda neophyte. I still love the bike, but just need to take a break from it.

[slamiste]

Eric,
I have a place in the dark part of my basement that I call "The Corner of Shame". That's where bikes go that I've become frustrated with either through my own short comings or other issued caused by other parties. Average stay in the Corner of Shame is usually a few years. The current occupant is my wife's 1942 WLA but will be replaced soon with a Moto Guzzi V1000 Convert.

Steve Slaminko

[HDSmitty]

I also have a "corner of shame" as I'm sure many of us do. (even though it may not be freely admitted to). Smitty

[exeric]

After a day of looking at this engine, and calming down from being P.O'd, I am wondering if the chain is just a bit tight, and that's just the way a new chain will be. The chain tensioner does not have a powerful spring, and I mean it can be compressed by hand so it's doesn't have the tension of something like a valve spring. I have no experience with Hondas, and the factory manual that I'm using doesn't give a spec. or an empirical example of how taunt the spring should be; hence, I don't know what the hell I should expect. The timing marks on the cams, and the crank come very close to lining up, but there is a possible 4 degree mis-alignment of all the marks and that is what has been bothering me the most, and makes me wonder if a looser chain would fix that. I can only relate this to the old American bikes I've messed with that have timing gears which wear with use, and can give you doubts about how accurate your pinion gear is to your points cam. So, unless some Honda expert chimes in and says DO NOT try to run that engine with even the slightest mis-alignment of marks, then I'm going to carry on and go for the gold I deeply thank those who have given me advice, and it is very much appreciated.

[aumick10]

From memory, if the spring is fully compressed, and locked in place, then installed on the motor. When the spring is released and locked again, the shaft will have moved maybe 1/2".

[exeric]

There's some good information. Thanks aumicm10; I'll give it a whirl

[aumick10]

I think the chain is 128 links.

[hogchild71]

Eric
Get a good manual. Take the chain adjuster out of the engine and lay it on the workbench. If you need the correct parts for your old Honda, call Western Hills Honda in southern Ohio (Indiana?)
Good luck, Fred