I have to have my valves adjusted because they are way too loose. I asked the shop that is doing the work if there was anything they could tweak while they were in there to give me a boost in performance. I told them I only have a slip on Yosh exhaust, stock air filter and I don't want to spend the money on a Power Commander. I also said that I didn't have a ton of money for race cams and major engine work. So, he suggested APE adjustable cam gears. He advised that by adjusting when the intake and exhaust valves open/close that you can get a performance enhancement and at only $60 bucks for the sprockets it was a very cheap upgrade. He also advised that valves that are on the loose end of their adjustment range can also provide a performance enhancement. The shop is a very reputable and has been in service for years. The owner has been working on and racing (drag strip) motorcycles for over 30 years so I am trusting he will take care of me. He advised the difference by doing these couple things will be like going from eating a really good hamburger to eating a really good steak.

He has asked me though to go online to CBR forums and get some suggestions on the best adjustments for how to set the gearing. Although I am sure he can make a good judgement call on how to set them, if any of you have gone through this and know they best settings, it could be the difference between a sirloin and filet.

Thanks for any input.

 

I don't think it is worth the trouble in my opinion.What are you looking at getting out of it by doing it?

 

It will just give the bike a bit more HP. I'm just looking to make the bike the best it can be without overhauling the entire engine. The same reason people put a full exhaust, K&N air filter and power commander on their ride...just to bring the bike to its full potential. I don't have the money to do the full exhaust and so forth. dialing in the cams with the adjusters isn't going to cost much more than the $60 in parts on top of what I am already have to pay to have the valves adjusted because they are too loose. I would never pay to have the adjustable cams put in if I did NOT already need to have the head off to do the valves.

 

Just drop a tooth on the front sprocket and call it a day.

 

adjusting valve timing will NOT get you more power. it's like dropping/adding teeth in the drive sprockets, or adjusting ignition timing. you'd be moving power around - but not adding any. if advance the timing - you're getting more power down low (sacrificing a little bit of top end). retarding it gets you power for redline (while sacrificing a lot of mid). then you're also changing overlap of the valves - which has it's own set of rules. more overlap (more top end - less mid). less overlap ( more mid, less top). it's all relative to eachother. if you look at a lot of racers who start adjusting valve timing - they're talking about gaining a few hp in mid while losing .5 hp at redline, or vice versa. and let me tell you, $60 is just to get you gears - which nets you nothing at all. testing and tuning (with a dyno) is what's going to get you results - and that's REALLY expensive. plus you're having to take the valve cover off each time to change degrees. it's trial and error. 1 degree advance on the intake might be good, 2 might be better - but it could be worse at the same time. and what effect does that have on the valve overlap? what are you doing with the exhaust cam at the same time? advancing it might be better for overlap, but it's not getting you anything mid range wise or partial throttle hp. is this starting to effect volumeric efficiency? you bet it is.... it might all net you nothing the way you decide to adjust it first. you need to try different combos.



and as far as loosening the valves up - that will not add hp. your shop is dead wrong. the valves open LESS when they are on the loose end of the spectrum. so, physically - it could only take away hp. (think about breathing in through a straw. if the straw has a bigger opening - you breath more. if it has a smaller opening - you breath less) having said that, bucket/shim valves tend to tighten over time with carbon build-up and things - so you won't have to adjust them quite as often. then again, we're talking .001 inch - not too much difference - so it's just a mute point. put them in spec, and leave them.




how hard do you ride your bike? what kind of maintenance are you willing to do yourself (to save money). and if you have tons of money - just upgrade bikes...

and lets not forget - one mistake and it could be BOOM. is this the same shop that couldn't get your motor running on all cylinders? i mean come on, the guy couldn't hook up the ignition wires up correctly... and then couldn't even correctly diagnose the problem....


i hear why you want to do this (you already have the cams off to shim the valves), but i would start smaller. if you're on the cheap, not too many miles on the chain, or quite a few, buy a steel front sprocket like letsride said and be done with it. much simpler and you can do it yourself.