Belt change: Now a whirring sound?

[csorin]

Is a crankshaft turning tool absolutely necessary for a belt change?  Can I just put the bike in gear and use the rear tire?  Thanks guys.

[Triple J]

Yep, you can use the rear wheel.

[vossy]

Yep, use the rear wheel. Place it in top gear and take the spark plugs out so it will have no compression on the stroke while you are turning.
I do this on my belt changes.

[WTSDS]

Yep, rear wheel works just fine. There's a thread somewhere on making your own tool.

[csorin]

Yep, use the rear wheel. Place it in top gear and take the spark plugs out so it will have no compression on the stroke while you are turning.
I do this on my belt changes.

Is it absolutely necessary to remove the spark plugs?  Does the lack of compression protect the engine or just make the job of turning the engine easier?

[yotogi]

Is it absolutely necessary to remove the spark plugs?  Does the lack of compression protect the engine or just make the job of turning the engine easier?

The engine deals with the compression you generate turning over the engine all the time while running, so don't worry about damage from that.

It makes the engine easy to turn over, allows you to determine if you are on the compression or exhaust stroke, and it can help you find TDC as you can put your finger over the spark plug hole to see if there is compression.

[csorin]

Thanks to all who helped with this.  I pulled the spark plugs, much easier than I had anticipated, and used my finger to plug the hole and feel for top dead center as my friend turned the rear wheel.

The belt change went fine.  I used the ducatitech (ca-cycleworks) videos to help me along, and took advantage of his marker technique.  The belts were tightened so that a 5mm allen wrench could fit under the roller but a 6mm could not.  Tension bolts were torqued according to the desmotimes book.

My concern now is that I get a "whirring" sound from the engine around 2700 and up RPM.  It either fades off around 4500 or the exhaust overshadows it.  I listened with the timing belt covers off, and believe it to be coming from the vertical cylinder camshaft.  I'm fairly certain this is a new sound, but not sure if the belts need to just settle, or if something is wrong.  I rechecked my tensions and torque settings, but the sound continues.  Any thoughts on this?    

[csorin]

Alright,

Did some research.  Possible explanation could be that the belts are too tight.  One thread mentioned that new timing belts will "whistle" (I'm assuming this is the same sound I'm getting) as they break in.  Should I recheck the belt tension, or write it off as normal break in noise?

Also, desmotimes and posters on here mention that the belt rollers should spin freely and not "bind".  What exactly does this mean?  Should I be able to spin the roller, let go of it, and watch it continue to spin?  Should I just be able to turn it easily?  My rollers would turn easily without any tough spots, but not spin like a top. 

[ducpainter]

The noise may indeed be from overtightened belts, or your old belts may have been very loose.

Re: the rollers, no they won't spin after you let go. The bearing should feel smooth with no binding or 'notchiness' as you describe.

[Howie]

You might want to go back and check belt tension again.  Until you get the feel you want to make sure a 4 mm allen goes through with no resistance. 

[seevtsaab]

Very good point about the rollers not spinning freely - a free spinning roller / pulley is one with no lubrication.

[csorin]

Alright, went back and rechecked belt tension.  I ended up loosening it up a bit, as a 5mm allen would pass under with A LOT of force, and a 6mm was absolutely impossible. 

Now it is set for a 5mm to pass with a pinch of resistance, and a 6mm will pass with A LOT of force combined with rolling the allen key.  Howie, I didn't check, but I imagine this would equate to a 4mm passing with no resistance.

The whirring noise has settled.  It is still present, but much less prevalent.  I'm going to call this good to go.  The valves need to get checked in about 800 miles, a job my mechanic will be more inclined to take on. 

Thanks everyone for the help.