My sons 05 yfz 450 needed a new crank. we are replacing it with a hotrod stroker crank.
before this happened-we were told he could retard the exhaust cam one (1) tooth, and get more power.
Is this still a good idea with the stroker crank, or is there still enough room to do this without damaging something?
Hope this makes sense to someone..
I am relaying what my Son asked me.
thanks,
Glenn

 

I have heard that before but I've never tried it, it makes me nervous changing the cam timing. I can't say for sure but with the stroker kit I would worry that the valve would hit the piston. Maybe someone else who has done it can chime in.

What I have done is change ignition timing to get more power. For my Raptor I got a Dynatek Programmable CDI which comes with 4 pre-programmed timing curves and depending on what compression you are running you can change the curves and load to the CDI them from a laptop. It has a selector switch that you can switch between the curves. With stock compression you want to advance the timing. With high compression you want to retard the timing a bit. The nice thing is you can mess with it as much as you like till you find the optimum setting.

 

The cam mod for the yfz if a very common practice. Basically from what I've read is that it gives you the same timing as the yz450f dirt bike. Everyone says that it will not harm the engine in anyway because it was designed for that timing.

Now if it has been stroked, I don't know. I would think that the stroker would compensate for the longer stroke to give you the same head clearance otherwise it would probably raise your compression. I'm gonna say you should be safe to do the mod but, don't rely on my word.