Wanting more power

[oldguy]

no I am basing my facts on my 2006 YZ250F that I built up. The post on TT with dyno numbers helps reinforce the fact that there is power to be made by porting the head.

What are you basing your opinion on OT? How many YZFs have you ported out is what I am asking? If you say none, which I expect, your opinion is without facts.

As Rich said I am not a mechanic and trust our engines to only Eric Gorr and Rich for the work. My opinions are just thAt- but based on the seat of the pants experience of my son racing them (his qualifications while not a national pro rider he is in the upper 20% of our district A class. He is quick and tends to ring every bit of power he can from a bike). We do not rush a new bike in for mods as soon as we get it but instead he practices and races it for several hours (usually until the first valve replacement is due) and then we have Eric or Rich do their magic to it. Every time we get a bike back there is a line of other A riders waiting to test it out and compare to their own bikes- some stock and some highly modded and the usual opinion is that the bike is faster and stronger then their own.
So if I have to hold the tools and mess up my engine you are correct I don't have any facts. But if common sense and seat of the pants testing by several riders is of any value in the real world I am qualified to sp[eak on the results.
BTW I have seen many people gets hands on with snowblowers and chop off fingers- does that make them experts in the design of the augers? You above statement would support that statement. Anybody can pretend (especially on the internet) to be an expert but real world shows the differance. I rely and trust in my 2 chosen mechanics I would like to see some of your qualifications as an engine builder besides opinions backed up by the dimpler's assertions. Remember you called me out first and I have been honest on my lack of hands on :nod:

 

[oldguy]

Rich

Are you a motorcycle mechanic by trade? I have a 99 YZ 400F and it seems you have plenty of experience with that particular configuration. Do you build engines for the general public as a business or is it just a hobby?

JB rich is the kind of guy that finds the challenge of making something better by tearing it apart and studying it entertainment. Here is a thread that if you read through the fun stuff details just how Rich and Eric Gorr attained their standing in the Moto world
http://www.dirtrider.net/forums3/showthread.php?t=42225&highlight=rich+rohrich

 

[jb_dallas]

Thanks oldguy

I read alot of the thread....very interesting.

 

[Rich Rohrich]

Rich

Are you a motorcycle mechanic by trade? I have a 99 YZ 400F and it seems you have plenty of experience with that particular configuration. Do you build engines for the general public as a business or is it just a hobby?

My day job isn't in the motorcycle business (the pay is way too low) but I've kept my hand firmly in it.

About 6-7 years ago when Eric Gorr decided to get seriously into the four-stroke performance market I worked with him nights and weekends doing cylinder heads (flow bench R&D, porting, valve jobs etc.) and complete engine builds. I worked with him to develop some of the processes and specs he uses. We also worked a lot on engine forensics to get a handle on the cause of catastrophic failure in late model MX engines and what could be done to prevent them. Eric has a wealth of data and experience in this area on all types of engines.

I did that for a few years until Eric relocated to Madison, Wi. At that point I wasn't able to work with him any longer in the same capacity.

These days my involvement is more as a curious observer who plays at home on the flow bench whenever a new model cylinder head crosses my path, and the occasional sounding board for Eric's new ideas and concepts.

I hope that answers your question.

 

[whenfoxforks-ruled]

Thanks for being you Rich! Old guy, I couldn't have said it better, really! Matt, sit back and reflect, this sure sounds like "quad information", doesn't it? You were not around when the dimple guy got ran through the ringer? Vintage Bob

 

[jb_dallas]

Thanks Rich, you answered my question. I guess I need to contact Eric Gorr when I need work done. If I was smart, I would sell the YZ before it needs a rebuild and buy a WR or 450X, but Im already knee deep in it now.