Cam Timing

[ribbert]

For the guys running out of inexpensive mod ideas.

Having noticed some time ago that my cam timing was off spec and having to choose a 1/2 tooth either side of correct,  I recently installed RPM adjustable sprockets and returned the timing to spec.  I made a point of riding the bike before making other changes so the effect, if any, could be evaluated.
I am pleased to say the was a noticeable difference.
The motor had a less laboured sound to it at idle and had crisper throttle response, particularly at lower revs.  I then move on to carby overhaul, re-jetting and Unipods.
All up, very pleased with the changes.
Mind you, my ears still hurt from the induction noise at 6000 plus on WOT without earplugs.
Noel

[SlowOldGuy]

Noel,
Did you degree the cams or just use the sprockets to line them back up to the factory marks?

If you degreed them, what did you choose for the lobe centers?

DavidR.

[ribbert]

Noel,
Did you degree the cams or just use the sprockets to line them back up to the factory marks?

If you degreed them, what did you choose for the lobe centers?

DavidR.

David,
I installed them just prior to a big trip and didn't have time to play around.  I used them to return the timing to spec ( punch marks through the caps )
I am aware of the timing options but have not researched the subject recently, nor do I recall any conclusive results to varying it from spec, although I may be corrected on that point.
I will read all the info here and reassess the options but I am not interested in a few extra horses at the top end at the expense of low and mid-range power though.  It's a road bike not a racing bike.
It's a long time since this subject has been raised.
Anyone want to throw their 2 bobs ( cents ) worth in?
Noel

[motohorseman]

For the guys running out of inexpensive mod ideas.

Having noticed some time ago that my cam timing was off spec and having to choose a 1/2 tooth either side of correct,  I recently installed RPM adjustable sprockets and returned the timing to spec.  I made a point of riding the bike before making other changes so the effect, if any, could be evaluated.
I am pleased to say the was a noticeable difference.
The motor had a less laboured sound to it at idle and had crisper throttle response, particularly at lower revs.  I then move on to carby overhaul, re-jetting and Unipods.
All up, very pleased with the changes.
Mind you, my ears still hurt from the induction noise at 6000 plus on WOT without earplugs.
Noel

I'm debating on whether or not to go with individual pods. Do you believe they added significant power?

I'm happy with how my FJ performs, but always want more.

The cam timing adjustment sounds like something I'd like to do, for sure.

[eddohawk]

From a novices perspective..Having been through the reinstall of the cam shafts I well remember how much trouble I had lining up the punch marks through the caps and keeping tdc etc. How do the adjustable sprockets ''work'' in terms of the sequence of the camshaft tensioner reinstall?

I'm guessing you tighten up the caps with the punch marks lined up correctly first and then loosen the adjustable sprockets to get tdc perfect using a timing light?

[JMR]

From a novices perspective..Having been through the reinstall of the cam shafts I well remember how much trouble I had lining up the punch marks through the caps and keeping tdc etc. How do the adjustable sprockets ''work'' in terms of the sequence of the camshaft tensioner reinstall?

I'm guessing you tighten up the caps with the punch marks lined up correctly first and then loosen the adjustable sprockets to get tdc perfect using a timing light?

You use a degree wheel/dial indicator to degree the cams and a piston stop to find true TDC. I have also used a dial indicator (to find TDC) with centrally located sparkplugs. Timing cams is not that difficult but you have to think it through and read about it if you are trying for the first time. I recommend checking the timing at actual running lash.....it is very difficult to achieve zero lash (recommended by Megacycle /Web) with shim/bucket set ups. Monuting the degree wheel can be a PITA on the FJ.....I made a tool that allows the mounting of the wheel and the turning of the crank without wheel shift.

[andyb]

Meh.  If you have stock cams, that's overthinking things imo.  Get a true TDC figured out, put the sprockets where the markings on the sprockets align with the mating surfaces, crack the sprockets loose and move the cams under them until the dots are centered.  If you're  still at TDC and haven't moved, you're done.  Turn the motor over twice by hand slowly to ensure that you're not massively retarded, and get on with things.

Makes quite a difference moving them back to where they belong though.  Even a relatively mild change makes for a noticable difference in feel.