Idle Problem Solved

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Think you'd have to tip the bike upside down to get the cam sprockets to skip, wouldn't you? ;)
Not necessarily. Depending on where the engine arbitrarily stops, one of the camshafts can be under torque from one of the valve springs pressing on the side of a cam lobe. When the chain tension is released it can allow the cam to rotate off the lobe. Maintaining chain tension when the CCT is removed prevents and slippage anywhere.

 
Last edited by a moderator:
Thanks for updating and glad you are taken care of.

I've got a cylinder head off of a '04 in my garage along with the cams and a cam chain that I might be able to play with. I've also got 11 crushed valves plus one valve that is so mangled that it can't be driven out of the guide which may limit what I can look at. Next time I have a chance I will take a look at cam misalignment and valve/piston clearance.
That would be great. There's no real answer on how much of a chain skip needs to occur before valve damage. Mine also skipped one tooth on valve adjustment and it ran fine, just lower idle and a really flat midrange.

 
Think you'd have to tip the bike upside down to get the cam sprockets to skip, wouldn't you? ;)
Not necessarily. Depending on where the engine arbitrarily stops, one of the camshafts can be under torque from one of the valve springs pressing on the side of a cam lobe. When the chain tension is released it can allow the cam to rotate off the lobe. Maintaining chain tension when the CCT is removed prevents and slippage anywhere.
I'm not 100% on this one Fred, I'm thinking that a different lobe will be 'hiding in the wings,' prepared to apply opposing pressure to minimize the reaction. But the bitter bottom line is your last sentence...."Maintaining tension........." Do that and keep the evil scenarios at bay!

...Think you'd have to tip the bike upside down to get the cam sprockets to skip, wouldn't you?...
In an unadvertised special, there is a cam chain slipper in the valve cover that helps hold the cam chain in the cam gears.
Yes there is! I wonder if it's close enough to the chain to keep it from jumping the cam sprockets?

 
Last edited by a moderator:
Top