Installing exhaust cam

[phoenix02]

I'm reading a lot about having to fight the left exhaust valve when reinstalling the exhaust cam.  I'm wondering what would be wrong with installing the intake cam and chain tensioner, putting the caps onto the exhaust cam, finger tightening the bolts, and turning the crank backward enough to take the lobe off the shim on the left exhaust valve? 

[Watcher]

I'm having a hard time picturing this.  The only reason a cam should fight you being bolted down is if a lobe is trying to open a valve while you are torquing it down, and that's not only a bad idea and introduces a danger of stripping the bolts, but it's likely the lobe would just rotate off the valve anyway.

If you're doing this with the engine at TDC, which you SHOULD be because timing, the lobes should all be off the valves and the cam should have little resistance to full torque spec.

[gsJack]

When the cams are properly timed with the rotor on the top dead center mark and the cam notches pointed inward the left exhaust valve is partly open.  Should be set this way and that's how I did it but cam caps must be drawn down slowly and carefully to make sure locating dowels are properly engaged and nothing gets broken.

[phoenix02]

Once the sprockets are engaged in the chain, the valves are timed.  It doesn't matter that you rotate off TDC to complete installing one cam.  I read no objection to installing the exhaust cam this easy way yet.  I'll give the community another day before I go for it.

[Watcher]

Thanks Jack, been a while since I had done my top end, and I had torqued the cams down "loose" and then set the timing.


I don't see a problem with slacking the chain to rotate the cam off TDC to torque it down.  Just take the chain tensioner off, it'll make things a lot easier.

[phoenix02]

I've got my tensioner in and engaged so the chain is tight, although the one side of the exhaust cam is raised.  I was planning to rotate the crank (and cams) slowly backwards just like that.  The tensioner ratchets out so it's not like it's going to compress when the chain goes tight on that leg.  For the life of me, I can't imagine why fighting the left exhaust valve is standard assembly procedure.

[phoenix02]

The phoenix02 method worked like a champ.  Engine running smooth after valve job.   

Can't road test it due to rain. 

[Watcher]

Can't?  Or won't? 

[phoenix02]

Road tested.  Bike runs great.  BUT - Oil leaks from under the jug.  Waaaaaaaa!!!   

I didn't pull the cylinders so I didn't replace the gasket.  Can I even get the cylinders off while the engine is in the frame?   

[phoenix02]

This is a 2005 so it doesn't have a tach cable.  Really does look like it's leaking at the cylinder base.  Coming out fast enough to catch the wind and spray all over the lower engine and fairings in just a mile of riding.

Is the head gasket shot since I torqued it down and rode it a couple miles?

[Watcher]

...  you didn't change the head gasket?


Edit: nevermind, I understand.


You *should* change the gasket again.  I wouldn't recommend reusing a compressed gasket.
That being said, I've done that with a Briggs 5HP without problems.

But any job worth doing is worth doing right.  If you need to order a gasket for the jugs anyway you might as well just order a new head gasket.