[kevdusmc]

Am I hearing correctly that some people have had their cams adjusted on a brand new bike? The scoop I heard was that the cams are not always adjusted properly from the factory, especially on the 4v bikes. Is that true? Is there a worthwhile performance gain in having this done? Thanks.

 

[908SSP]

Had mine done at the 600 mile service. Overall gain of about 5 hp. Runs way smoother and warms up much quicker.

Hi Scott while I do recommend having the cam timing checked and set I doubt that "runs smoother and warms up...quicker" would be the result. That is more likely the result of adjusting the fuel injection. Cam timing can have power sapping effects so the power gain could in fact be the result of the cam timing.

 

[908SSP]

"Way off" just how far off were they? You might be right if they were that bad. But a few degrees off wouldn't show up at low rpm, where you would notice warm-up and smoothness. Most of the time on a four valve changing the cam timing is as much about optimizing the timing. Run a little more over lap pick up a little high rpm hp less over lap pick up a little torque. Just curious did set your cam timing to stock position?

 

[brad_black]

smoothness is one of the most noticeable improvements when reseting the cam timing in my experience. really helps. plus response and power output too.

dunno about the warm up bit, but it will like being a touch richer than it was probably, and the warm up trims are on the rich side usually. so it will tolerate it more.

 

[908SSP]

Brad I am sure you have more cam timing experience then I do so can you explain why it might be that a couple of degrees would make the engine more or less smooth? Also is there a difference if you adjust for top end power or low end power? Or is it a case of running rough if the front cylinder is adjusted for top end power and the vertical cylinder is adjusted for bottom end power? Since you also adjust FI can you honestly tell us that you make your cam timing experiments in a scientific manner that you don't in anyway touch the FI when doing cam timing so that the smoothness you experience is related to cam timing and nothing else? I am not trying to talk anyone out of checking and setting their cam timing I am just curious why you would say smoothness is effect you connect with cam timing? Of course this could all be a mater of degree like I said if one cam was out a fair amount say 6 degrees or more I suppose that could be noticeable.

 

[Speeddog]

IIRC, one of Scott S.'s cams was out by 10 degrees or so. If it was, for example, an exhaust cam that was closing 10 degrees later than it should have, that's a lot more overlap. It would definitely not run as well at low RPM that way. It'd be even worse if the intake was opening early on that cylinder too....