Cam timing settings

I have a CBR 1000F 1990 Honda. At 17000 miles I started getting some cam
chain rattle, so I replaced the spring loaded tensioner and guides. And I
marked the cam sprockets' locations at TDC on #1 cyl on the compression
stroke. But I noticed that after putting the cams back with my marks lined
up like when I took it apart, that the factory EX and IN marks on the gears
aren't lined up exactly with the valve cover mating surface. The IN (intake
cam sprocket) is lined up, but the EX (exhaust cam sprocket) is about a
tooth off. I can't find my Haynes manual that i've missplaced over the
years.
The old tensioner was stuck about in the middle of it's travel (btw)
Anyone know where I can fine a pic of the cam gear locations?

Thanks,

Kent

 

If the cam sprocket has 30 teeth, 360/30 = 12...

But the camshaft turns 1 time for every 2 times the crankshaft turns,
so 12/2 = 6 degrees off. If the exhaust valve closes late, the engine
gets really "cammy", you have to rev it higher to reach the power peak,
there's more overlap. If the exhaust closes too early, there's less
overlap, the engine gets really *torquey* and won't rev up. Have you
noticed anything like that?

By any chance, did you remove the camshafts and reinstall them with the
spring loaded cam chain tensioner in place? The engine should be turned
to TDC on the #1 cylinder, at which point there will be clearance on
the intake and exhaust valves of #1, the exhausts of #2 will be
completely closed, so there will be clearance on #2 exhaust, and #3
intakes will have clearance, too. #4 intake and exhausts will be open.
Then you remove the spring loaded cam chain tensioner so you can nudge
the exhaust cam sprocket to the correct position. You wouldn't have to
loosen up the cam bearing bolts, just nudge the cam, pick up the cam
chain and move it one tooth and reinstall the
cam chain tensioner and release the spring so it can adjust itself...

Then, with the spark plugs removed so there will be no resistance from
compression, rotate the engine several times manually to be sure the
valves are hitting each other and that the pistons aren't hitting the
valves and put the valve cover back on...

 

Thanks for all the help guys... I went to the Honda shop today and took a
look at their Honda manual. Both cam gear marks line up with the top of the
head... kinda figured that...just making sure


Thanks again,

Pete

 

Glad you got it sorted out. FWIW, you really should consider purchasing
the Honda manual, they're very good. Certainly better than that Haynes
that's lost in your closet (back of the top shelf, I looked ;-).

 

Put my CBR back together this weekend.. It runs great..no more chain rattle

Bought a new fulmer helmet and a motogp jacket.. now if i can afford some
gas

Pete
alias Kent

here's a pic of my bike http://webpages.charter.net/kgolden