Jumping camchain

corpy · #1 PostAuthor: **corpy** » Mon Jan 23, 2012 6:17 pm

Another damn fool question.
I am just fitting the camshafts to a Kaw 1100 A1 (1982) as per Kawas and Clymer manuals.
I am as sure as I can be that the lower end of the camchain is still on the sprocket down below; I can't quite see it at the bottom of the tunnel even with a mirror but it responds to the slightest movement of the crankshaft and I can move the c'shaft by pulling on the chain by hand.
When I get to a certain point in clamping down the exhaust camshaft i.e. when the cams and valve springs are seriously resisting, the chain not only moves the crankshaft, it also jumps two or three teeth on the sprocket.
I can make a tight-fitting spanner for the crankshaft nut and fix it to a convenient part nearby, and I suppose that that will hold everything.
Perhaps lightly, temporarily, install the inlet camshft camchain tensioner, or bung something up the hole?
There is no mention of this in the two books and, being more of a 1950's Velo/BSA, and in expert K country on this forum, I am proceeding with caution on this highly admired engine.
Comments welcomed.

z1bman · #2 PostAuthor: **z1bman** » Mon Jan 23, 2012 6:36 pm

whilst tightening the cam caps you need to keep some pressure on the chain between the inlet + exhaust sprockets to prevent the chain from moving on the sprockets keep the tension there until you have fitted the cam chain tensioner + rotated the crank one revolution

zed1015 · #3 PostAuthor: **zed1015** » Mon Jan 23, 2012 6:44 pm

You should be fitting the exhaust cam first (is this the case?) and there will be no tension on the camchain.
Where abouts in linc's are you, if you are close i would be happy to come and help.

jimmock · #4 PostAuthor: **jimmock** » Mon Jan 23, 2012 7:33 pm

zed1015 wrote:You should be fitting the exhaust cam first (is this the case?) and there will be no tension on the camchain.
Where abouts in linc's are you, if you are close i would be happy to come and help.

Corpy,

Don't let him come round!!!

I've heard he'll eat all your biccies, drink all your tea AND coffee and try and stay over!!!

YOU HAVE BEEN WARNED!!!

Jimmock.

PAULJAC47 · #5 PostAuthor: **PAULJAC47** » Mon Jan 23, 2012 8:12 pm

Make sure you are on TDC 1/4 fit exhaust cam first can be a bit of fiddle!!!

corpy · #6 PostAuthor: **corpy** » Tue Jan 24, 2012 12:07 am

Thanks for the replies.
It seems to me that the exhaust camshaft wants to rotate as the caps are tightened down, due to the pull of the cam faces against the valves.
There is no problem really - I just have to somehow hold the crankshaft still and take care to keep the chain run from cr'shaft to camshaft tight.
My two books are good at warning about such things, but they don't mention this. I wondered whether experts have a technique.
Thanks.

zed1015 · #7 PostAuthor: **zed1015** » Tue Jan 24, 2012 1:09 am

Yes! the cams always do that.
No need to lock the crank.
Just bolt the camshaft down and if the timing has moved afterwards there's enough clearance between the cam sprocket and head to jump the chain the required amount of teeth to set things right.

PAULJAC47 · #8 PostAuthor: **PAULJAC47** » Tue Jan 24, 2012 5:27 pm

Best way is to position the cam so when you tighten down caps the arrow that need to be level with head surface is just below where it needs to be,use a soft lever in its teeth(with camchain pulled away from the teeth)to lever it up to aligned postion,then fit camchain pulling hard to make sure its on the bottom cog,fit inlet cam with required link distance and mark alignment and lasty top wheel and tensioner,turn her over slowly on crank a few times to make sure all is free and lines up..Paul J ps dont be tempted to torque cam cap bolts just nip em up,dead easy to strip!!!