cam chain issues on 72 CB450

[MJPriceisright]

hello, i have a build thread going and i have found myself in a predicament of timing issues.. as you can see from the pictures, while the motor is at TDC, the intake cam is right on the money, but my exhaust cam is slightly off. what i can tell is that if i move it a tooth it will be then below the cam mark, could this be an issue of cam chain stretch? i have heard stories of guys removing the original chain and its longer than the replacements.. so basically i am looking for someone to tell me whether this is close enough, or do i need to order a new chain and make sure both sides are dead on the money.. any replies or insights are mostly appreciated!

 

[joeyputt]

Brother it looks like it could be a tooth off, have you tried to move it one tooth and see how it aligns? Due to machining tolerances it is acceptable for one of the marks to be very slightly off however yours is definitely farther off that what would be acceptable. Cam chain stretch will affect timing marks however as close together as the two cams are in a CB450 engine it would most likely affect both timing marks especially if the mark is that far off, also on a CB450 engine if the chain was stretched it would be off on the other side of the timing mark. Have you checked to make sure that the chain is properly seated on the roller gear in the tunnel between the cams? I can see that the one cam bearing housing is loose in the one photo however in the other photo you have a lot of end play on the cam so if you have both of the cam bearing housings bolted down for that cam you have too much end play and will need to correct the problem by either replacing the worn cam bearing housings or shimming the cam.

 

[MJPriceisright]

hey joey thanks for the input, no the housings are lined up and in place i just didnt lock them down cause i had to pull them to re-align the cam gears to get them as close as possible.. i did however order a new chain and tool to do it with a fresh chain, i figure why not if im here, might as well do it.. but you're saying its too far off, my gut feeling as well. thanks man

 

[joeyputt]

You are welcome Brother. If you move the cam one tooth with your current chain it should be in the right place, it would most likely be a little bit off to the other side which would be caused by the stretch in the cam chain however it would probably be ok. Installing a new chain would be the safest way to go just make sure it comes with a master link as you can not install a one piece chain in the CB450 engine due to the tunnel in the top of the cylinder head. You probably already know however there are also a couple of roller guides below the head so hook your new chain to your old one while it is still in the engine and pull the new chain through with your old one as you remove it if you are not going to remove the cylinder head.

 

[MJPriceisright]

joey got the new chain and link in last night, ran it through and everything is right on the money, looks perfect.. thanks for your help, here is the link to my thread, follow along in case i need more newb help! lol

http://www.dotheton.com/forum/index.php?topic=36042.msg463059#msg463059

 

[cb450cf]

How did you space out the camshaft?

 

[fordop87]

Dd you have hell getting the timing right? My brother and I fought mine for an hour and still ended up a link off. Had it all lined up, then turned the crank and we were a link off, maybe two. Must of had slack in one side.
Wonder if you have any tips for getting it set right. The manual doesn't really describe much of the process.