Topic: cam chain adjustment

[tlbranth]

I've read that 15deg ATDC on #1 firing stroke is where the crank ought to be to adjust the cam chain. Just as an academic exercise, what difference would it make which piston was on its firing stroke as long as the 15 degree measurement was adhered to? The idea, I guess, it to have the cam in a position such that the font of the chain is tight. Since the engine is symetric, what's the diff?

[MCRider]

It doesn't make any difference that I know of. I've never cared. The rule was 15° ATDC 1-4. No special noting as to which cylinder is where.

If you are setting the valve clearance, then it must be on the firing stroke. TDCC

[strynboen]

your trying to find that point vhen the cam are in ballance..betveen opning and cloasing valve, to get max slack,that are only on top point at cylendet +15 degree..the other valvets are in other posisions. vhen they not are in fire posision.and can not stand at this"top  balance posision"..thats are mine teori..but it can be done at all silenderes.at top + 15..but at fire stroke,,,so it have to folov the ignision and fire stroke
its just easyest to do at cill 1..to take plug aut and turn to kompresion koms..and slov turn to marked
but im not expert..just having fun and use  all my money on old honda"s

its cb 500/550??

[MCRider]

your trying to find that point vhen the cam are in ballance..betveen opning and cloasing valve, to get max slack,that are only on top point at cylendet +15 degree..the other valvets are in other posisions. vhen they not are in fire posision.and can not stand at this"top  balance posision"..thats are mine teori..but it can be done at all silenderes.at top + 15..but at fire stroke,,,so it have to folov the ignision and fire stroke
its just easyest to do at cill 1..to take plug aut and turn to kompresion koms..and slov turn to marked
but im not expert..just having fun and use  all my money on old honda"s

its cb 500/550??

Its a CB750.  I think the 500/550s cam chain is set with the engine running.

The setting must be on the 1-4+ 15°, but it doesn't matter which is on the fire stroke.  Interesting question. I may be wrong after all these years. I'll try it next time I'm in the shop, by measuring how far the plunger goes in at #1 firing stroke and #4 firing stroke.

It shouldn't be on the 2-3, so i would modify your "all silenderes" statement.

2-3 may work, but is not optimal. Never tried it.

[tlbranth]

your trying to find that point vhen the cam are in ballance..betveen opning and cloasing valve, to get max slack,that are only on top point at cylendet +15 degree..the other valvets are in other posisions. vhen they not are in fire posision.and can not stand at this"top  balance posision"..thats are mine teori..but it can be done at all silenderes.at top + 15..but at fire stroke,,,so it have to folov the ignision and fire stroke
its just easyest to do at cill 1..to take plug aut and turn to kompresion koms..and slov turn to marked
but im not expert..just having fun and use  all my money on old honda"s

its cb 500/550??

Stryn: if 1 is intaking, then 4 is firing. What's the diff? Seems to me 15 deg ATDC on any cylinder - firing or not - is equivalent.

[strynboen]

piston 1 and 4 are up at same time,,,but..not firing together..ok vaist kick..but only one are in kompresion stroke..thats mean that the cam are different   on this 2 cilenders.  the cam are different on all  4 cilenders.thats why its only works on that  spec  firing cylender..big bang engines rune parelel firing..but not standart sohc..

but my english are hell...and have only wor´ked on sohc last 3 years..so get some of the old mens word..they have done this in 30 years+

[tlbranth]

piston 1 and 4 are up at same time,,,but..not firing together..ok vaist kick..but only one are in kompresion stroke..thats mean that the cam are different   on this 2 cilenders.  the cam are different on all  4 cilenders.thats why its only works on that  spec  firing cylender..big bang engines rune parelel firing..but not standart sohc..

but my english are hell...and have only wor´ked on sohc last 3 years..so get some of the old mens word..they have done this in 30 years+

Strynboen: my point is it doesn't matter WHICH one is firing, the forces on the cam are the same - just at a different end of the engine.

[Ricky_Racer]

Its a CB750.  I think the 500/550s cam chain is set with the engine running.

Can anyone verify this statement? I didn't see anything about this in the manual and I need to know ASAP. Thanks! RR

[MCRider]

Its a CB750.  I think the 500/550s cam chain is set with the engine running.

Can anyone verify this statement? I didn't see anything about this in the manual and I need to know ASAP. Thanks! RR

Here's the FAQ on the subject. Seems to be either or for the 500/550.
http://forums.sohc4.net/index.php?topic=369.0

[Ricky_Racer]

Thanks for the link, Mac. So, "The 500/550 may be done either running or not running, but the best method is not running." That explains my corn-fuzion.     RR

[Duanob]

Funny but whenever I try and adjust it runing it seems to get worse so I adjust it statically. I think the 15 degree ATDC would produce the slackest point in the chain/stroke and thats why you adjust it then.