Cam timing readings.

[planter87]

right ok, so its not a waste then, how then does the cam sensor pick up on the early motor? is there a lump on the cam or is it off a bolt head?

[FASTER !]

Hi Planter , there is a difference in the sprocket , the front cylinder inlet sprocket as a raised / machined , square shaped bump on it if my memory serves me !!!

[Micah / AF1 Racing]

Yes, sorry, if gen2 sprockets use only on the front inlet cam if keeping the peg attached. Just press it out if it concerns you. It will still be a functional set of cam sprockets for you.

[planter87]

to make matters a little more complicated i've just spotted the sprockets on

http://www.af1racing.com/store/Scrip...dproduct=38448

which have the big peg as you say, but mine looks like this, if it works correctly.

[FASTER !]

That looks like a gen2 sprocket to me. Micah can help here as I dont have much experience on the gen2 ; its possible that sprocket could work on the front cylinder inlet cam but you will have to check that it doesn't foul anything.

Micah , can you chime in here ?

[derbybrit1]

to make matters a little more complicated i've just spotted the sprockets on

http://www.af1racing.com/store/Scrip...dproduct=38448

which have the big peg as you say, but mine looks like this, if it works correctly.

The photo on the link clearly shows the Gen II front intake cam sprocket with the long peg. It is long because it has to sensed by the Hall sensor in the cam cover. That sensor is about 12mm diameter

The photo on message #19 is the Gen I front exhaust cam sprocket with the short peg. It is short because it has to be sensed by the VR sensor on the cylinder head, which just has a small diameter (5mm?) central post. The long peg (Gen II) sprocket will not work on a Gen I motor as the cam sensing sprocket. And neither will a short peg (Gen I) sprocket work on a Gen II motor as the cam sensing sprocket. They have different part numbers for a reason.

All Micah was trying to say in earlier posts is that if you remove the pegs from either Gen I or Gen II sprockets then they are now exactly like the sprockets that came without pegs, either Gen.

[planter87]

i tried to put a frontal view of the sprocket to show the number 732 stamped on it.but it wouldnt load. thats the confusing part is that you say its for a gen 2 if it has 732 and gen 1 if its 730, but if its going to work then thats all i wanted to know.

i guess i'll not fully understand until i take the front valve cover off and see what type of peg is on the sprocket that gives off the reading.

[derbybrit1]

Its the peg, not the stamped number, that makes the difference. The sprocket in your photos is clearly Gen I. No amount of wishful thinking will change that.

Do you already have a degree wheel, and know how to get it mounted on the crankshaft? Do you have an Aprilia crank locking tool to help you find TDC? Do you have a dial indicator and an assortment of mounting stands? If not, you might be in for more than this minor adjustment is worth. If your bike runs good. leave it alone.

[planter87]

i have a gen 1 bike, so all i was asking was which was this sprocket from.before tearing it all down again to find out myself. as to all your other questions, yes.

[Gabro]

732 and 730 gear are all the same. don't worrie about

[Sabre]

OK, for the guys that have done this would you recommend 108/108 or 106/109? Am I right to assume the 106 refers to inlet with the 109 being exhaust?

[Micah / AF1 Racing]

Yes the first number in the pair is the intake lobe center.

[Lttlcheeze]

Ok, i've got a few questions now...

I've never done this before, but am very mechanically inclined, and have done complete tear downs before.

I have an Indicator, and a Degree Wheel will be ordered shortly.

Now...

I assume the measurements (106/109) Refer to the point at which the Valve is fully open. To measure that, do you rotate the cam until you get the same deviation (say .01) from the constant dia (back side of the cam) on both sides of the lobe? In other words, 0.0 is set on the back side, rotate until you see .01, record the number, continue to rotate past the lobe until you see .01 on the other side, record the number, average your numbers.

Is that right?

[kzmille]

Yes but use a common value of valve open. Usually 1mm or 0.040-0.050". Half way between is lobe center. The actual number is not important as long as you always use the same value. It's easier to be accurate with a number near 1mm rather than something like 0.010.

[Lttlcheeze]

Great thanks. I thought of a few more things.

-What is a good practice for adjusting the cam in the gear (I don't want to marr anything important up)?

-Should I use washers on the Cam Gear Bolts, as they will have less of the Cam Gear to "bite" on (since they are slotted)?