While I was sitting around bored, I got to studying some dyno pulls I have made in the past against some later pulls I have made on a few quads. I found when I compared them, the results were kind of neat. Here is a graph of 3 different quads, three different setups. Notice the two that run together almost identical are bike 1 and 2, bike 3 is the lowest of the the three. All three were run on the same tires (dyno tires), all are tuned in well, all have fresh maintenance (valve adj ect..). No headwork has been done to any of them. Heres the rundown..

1- 05, +3 Hot rods stroker, JE 13.5:1 piston, White Bros exhaust (full), 185 main, uni air filter with open box, SRP rev box, 02 CRF cam, VP110 mixed with 93.

2- 07, HRC head pipe, motoworks silencer, 172 main, CRF needle, green wire, 05 CRF camshaft, open airbox, stock filter. 93 octane

3- 05, HC2, stock head pipe, 07 silencer (modded), Twin air filter, open airbox, dynojet jet kit ( cant remember jetting but its as close to perfect as a DJ jet kit can get). 93 octane.

I found it kind of neat how bike 1 and 2 were close with such different mods.

i would have thought #3 would have done a little better then it did. the stock headpipe really chokes it down.

this shows how much easier it is to get power (up to low 50s) from a 06+ then a 04/05.

I dont know if i am impressed with #2 or wondering what is wrong with #1. Never really cared to much for strokers but i thought it would at least make more torque.

Keep in mind, this is an eddy current dyno. It will read lower than what almost all of you are acustomed to. #3 when stock only put down 28 RWHP, it actually has a better run netting it 34 HP at a later date with the same combo, just a few changes in the carb and I am incorrect about the pipe, it was an 05 silencer as well in that run, we later changed to the 07 silencer which helped a couple of HP.

Also, just for note sake, the 07 bone stock put down 32 RWHP right off the showroom on this dyno.

Im not really a fan of stokers either, but hey...you use the parts you have laying around when it comes time to build the backup bike. The head is where the power is, those 20 cc dont do anything unless you can feed them. I also dont think that 02 CRF cam really belongs in this picture of the 05. I feel a HC2 or even an 05 CRF would do better, at least more bottom end torque. In another month, I am going to remove the head, recut the seats and replace the valves and lay down one of my best port jobs on it and see what I can make without going bigger on the valves.

Heres the 1 and 2..

That super long headpipe is killing the power on that 05. I bet by just switching that pipe out for a decent pipe would yeild very good results. I bet the H2 like you said would do better as well.

I just came off of it with an "adjusted" HRC headpipe and CRF silencer, it made 40 HP with it. That WB pipe is a great bottom end pipe though, and thats what I was trying to achieve with this bike was a nice "outta the turn" snap. My 07 already has that snap I was looking for, but it also has a cam yeilding a bit more bottom end than the 02 CRF is supposed to, thats kind of why I thought the results were interesting. I figured the 05 would make maybe one or two more HP overall and have more bottom end than the 07 does, not the case.

wow i just noticed that headpipe in the pic and its different to say the least.

Yeah, thats a full white bros aluminum pro. The headpipe is long, and its a stepped header design. It actually works pretty well. I had that same pipe on my last 05 MX quad and loved it. I also have a couple of buddies that are pretty competitive in Pro-Am MX class that have ran that pipe and still do (well, carbon pro, but its the same thing).