1971 CB450 Cam Chain Issue

Finnigan

Finnigan

Over 1,000 Posts
Ground up rebuild and the engine is almost ready to go back in the frame. I ordered a cam chain and master link from common motorcycle collective and the chain is too short. I know there is a lot of discussion around lining up the chain correctly and after 2 days of carefully investigating I've come up with a decent method to get out all the slack involving threading the short end of the chain around the cams and resting the open end on the intake cam. Then 'feeding' the long end under the crank and rotating the magneto by hand until the chain begins to pull at the cam end.

Long story short the chain is ONE link too short. I pulled it all out and counted 127 links minus the master, Dime City sells a cam chain that is 128 links minus the master. Does anyone know what the correct length is? I've done everything I can think of including checking the routing of the chain over the rollers and making sure the eccentric valve adjusters are not pushing the cams further than they should be.

On another note, if I end up getting a chain with one more link will it be impossible to get the timing right or can I account for the extra length with the tensioner after install?

Any help is appreciated guys I'm at the end of my rope.
 
Something is wrong with your counting. Chains have only even number of links (including the master link) on motorcycles. So chains without a master link have to be odd numbered. There is no chain with an even number of links without the master link. You may be reading the description wrong.
 
Your reading is wrong, I said I counted 127 links without the master. So with the master, it has an even number of links.
 
127 + MASTER = 128 = even number of total links. The chain has one outside link and one inside link, so the chain can only be made with pairs, so even numbers only. The master is part of a pair, one of the inside links. So without a master, there must be an odd number. So no chains without masters that have even numbers.
 
Mydlyfkryzis said:
no chains without masters that have even numbers.
Click to expand...
Wrong. Not even gonna tell you why.
 

Attachments

  • mnthy.jpg
    mnthy.jpg
    31.2 KB · Views: 1,427
If you want to talk about every type of chain, the chains can be different lengths. But a Honda DOHC 450 uses a roller chain. S standard roller chain.

A standard motorcycle roller chain with a master link comes in odd links because 2 inner rollers have to be exposed. So these 2 sections have to be 7 links or 5 links, and if you add the master, they are even 8 and 6 links. Or put it another way, a standard roller chain has to have an even amount of pins.

jYqmig.jpg


Maybe you can put your spliff down and explain how you can have anything other than odd without master, even with master, on the standard roller chain.

Each of those lengths shown in the pic have odd numbers, the additi0on of a master link makes it an even number in every case.

Now if you want to talk about other styles of chains, like a hyvo or one like this:

Nf8GWZ.jpg
, then that's a different story.

But since we are not talking about anything in this thread but the satandard Honda DOHC can chain, a standard roller chain is the case.
 
I told you, I'm not going to tell you. You are wrong. You can explain it 50 ways and you're still wrong. The answer is easy and you probably already know what it is, but reject the reality that it exists.

The statement "So, no chains without masters that have even numbers" is false. End of story. Even for a standard roller chain. Even some cam chains. Nothing dramatic or personal, just a fact.

"It is extremely uncommon to see a standard roller chain of any type with an eneven number of total links, and in your application, more than likely has never been neccessary." would be a true statement.
 
Finnigan said:
Long story short the chain is ONE link too short. I pulled it all out and counted 127 links minus the master, Dime City sells a cam chain that is 128 links minus the master. Does anyone know what the correct length is?
Click to expand...


ok, I will make this incredibly simple for you because it can be confusing.

1. Technically speaking, the CB450 takes a 128 "link" chain, but forget about that in your case because the word "link", can, and has, caused confusion with some others on occasion, even though it IS technically correct as they define the term for their particular application.

Irregardless, you had an incredibly simple question, and basically, all YOU want to know is if your chain is the correct friggen length.

1. The correct length for your chain is exactly 128 ROLLERS . . This is because the number of rollers never changes, but the number of side plates and pins does which happens when a "connecting link" is added to connect the two ends together.

2. Simply count the number of ROLLERS in the chain . . Do NOT count the pins OR the side plates.

3. If you have 128 ROLLERS, and your chain is too short, it is simply installed incorrectly.

.
 
barnett468 said:
ok, I will make this incredibly simple for you because it can be confusing.

1. Technically speaking, the CB450 takes a 128 "link" chain, but forget about that in your case because the word "link", can, and has, caused confusion with some others on occasion, even though it IS technically correct as they define the term for their particular application.

Irregardless, you had an incredibly simple question, and basically, all YOU want to know is if your chain is the correct friggen length.

1. The correct length for your chain is exactly 128 ROLLERS, because the number of rollers never changes, but the number of side plates and pins does which happens when a "connecting link" is added to connect the two ends together.

2. Simply count the number of ROLLERS in the chain . . Do NOT count the pins OR the side plates.

3. If you have 128 ROLLERS, and your chain is too short, it is simply installed incorrectly.

.
Click to expand...

THANK YOU! Lol good grief that was a simple answer, much appreciated!
 
Finnigan said:
THANK YOU! Lol good grief that was a simple answer, much appreciated!
Click to expand...

LOL. even that answer was WAY more than you needed for your simple question. . All I really needed to say was "The correct length for your chain is 128 ROLLERS.".

Anyway, don't give up . . Count the chain and if it has 128 ROLLERS, then we can try to figure out what is causing it to end up a little short.

If it only has 127 3/4 or 127 11/32 pins, or rollers, or whatever the f_ck they are, it is still TOO F'n SHORT, and you will need to get the correct chain.


Hey Barn...exactly how many one and a half links does it take to make a chain for my 1968 Taco mini bike?

. . .
graphics-laughing-867787.gif


.
 
Its odd, last night I got a new chain (the first one was chewed up from so much trial and error) and started from scratch.

Took off the head and cylinders, routing the chain under the crank.
Inspected everything while I carefully put the cylinders back on, then made triple sure I routed the chain on the correct side of the rollers while I put the cylinder head back on.
I lined up the cam marks and set the crank to the LT position and still came up short!

Something I DID notice from 3 hours of pointless effort is that my intake cam is being pushed out by the valves. If it weren't I think I'd have enough space to link the chain up? Are the lobes supposed to be pushing against the spring force when everything is lined up?
 
Your cam lobes should be pointing approximately opposite of the valves if it has no rocker arms and uses shims on top of the valves so there is no pressure on the valves . . there are marks on the cams that show how they should be positioned when the piston is at tdc on the compression/fire stroke . . this occurs every other time the marks on the flywheel line up not every time they line up . . this has screwed up around a zillion people on cars also. .

After you think your cams are properly lined up, check them again because they probably won't be . . after that check them again . . one guy here checked his 5 times and they were still wrong.
 
I know this is a stupid question but for sanity's sake:

on the intake cam, which direction is the larger bore hole face? (clutch side?)
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light

    • Spread the Love

    Back
    Top Bottom