Rhc 06 Yz450 Bike Complete


14 replies to this topic
  • CROGGR

Posted April 16, 2007 - 10:11 PM

#1

It took over a year of testing and modding....but it is finally done and it's a rocket! I did everything one step at a time so I could record the performance gain every step of the way!


The first thing I did was fixed the handling issues with the bike. It didn't turn as well as I had hoped and it didn't go through the whoops as fast and as straight as I liked. Although stock was pretty good....pretty good doesn't cut it with me!:ride: While others tried raising the forks up in the triple clamps, changing tires, and different offsets.....I was able to fix both problems with a simple revalve of both ends...I'm not going to go in much detail here but, the bike handles better than any other bike I have ever ridden!


With all the handling and suspension issues ironed out it was time to move on to the biggest reason I bought a 450 in the first place POWER!!! The YZ has good power but not a lot of it. I one of those guys who rides a stock 500 2 stroke and says: this bike is kinda slow! I want a lot more! I was pretty sure I was going to be dissapointed in the power department but loved how the bike handled now and had decided to keep it anyway for a moto only bike if neccesary! I could always use my Perimeter Frame KX500 wonder bike to do everything else!


The first thing I did was try every pipe known to man and decided to keep the White Brothers Alumi Pro2. This bike added a lot of midrange and top end and didn't hurt the power down low. Other pipes helped the bottom end a tad but didn't come close the the WB in peak power!


The next thing I did was contacted www.ronhamp.com (RHC) He set me up with a carb mod. He bored the stock carb to 44mm and some change and modified the angle of the bore slightly to enhance the fuel charge! This added power across the board! I was very pleased at the additional power at every rpm level! It had picked up snap right off idle and pulled with much more authority! This was a very impressive mod!


Next I noticed the bike would stall very easy, so I opted for the Yamaha GYT 9 oz flywheel. It is a complete flywheel assembly that weighs 9 ozs more than the stock 18 oz. (for a total of 27oz) This was a big improvement to the overall character of the motor. It pulled harder off the bottom and you could run in a taller gear and not stall out. It did not make the bike rev noticably different it just gave the bike some meat down low and it was now able to chug it tight or slow going!


Next I installed a JE 13.5 to 1 piston. This gave the bike more power across the board. It felt much like the carb mod but not as drastic of a power increase. All together now with a slight mod to the ignition timing the bike was coming together and was quite fast with an excellent powerband but I wanted and needed more!!!


Next I shipped off the head to RHC (www.ronhamp.com) I left a note tied to the head which read "Dear Ron, please make fast and return ASAP!" I guess you should be careful what you ask for!!!!!!! I AM ABSOLUTELY FLABBERGASTED AT THE RESULT OF THE HEAD PORTING!!! It is truly amazing!!!!:thumbsup: : The porting felt like an increase of all the things I had done up to this point...times THREE!!! It is an absolute rocket!
It has so much more boost off the bottom and then it just explodes!!! I still cannot believe the power it puts out! It revs and pulls sooo much harder and further and faster it's unreal! This is the funnest bike I have ever ridd'in and now does every type of riding from moto to hillclimbing to desert better than I could've dreamed!!!! It's still capable of trail riding in fact, it's better, you just have to turn the throttle very carefully!:ride: It carburates way better and smoother at tiny throttle openings but you better be pointed in a safe direction when you turn the throttle hard!:worthy: It's perfect!!!!


The first victim of the RHC's porting wrath was my good friends Service Honda CR500! He just spent $11,000 on this bike and went with the aftermarket engine building mods. The mods proved not to be enough....my YZ walked it pretty bad. I made the mistake of letting him ride my bike.....now his bike is for sale! BY the way , my perimeter framed KX500 is now been sold! The only bad side effect of these mods are that you won't want to ride other bikes because they will feel sooo weak and boring in comparison. The stock 450's feel like a 250f now......


In conclusion, you can waste your $$$ on a lot of after market stuff and after market places that won't add much if any performance to your bike ( I know I've done it in the past) or you can have a world class engine builder build you a world class improvement! (RHC) Ron Hamp is the real deal!!! A big thanks to FFR (T-DUB) for all you help and getting me hooked up with RHC www.ronhamp.com .

  • twenty34

Posted April 17, 2007 - 02:07 AM

#2

Didn't you already post this last yr? You are pretty amped on RHC it appears, but all his dyno charts on his site AND his site are a few yrs dated.:thumbsup:

I refer to the expert GR...Is this place legit in your estimation?

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  • Ga426owner

Posted April 17, 2007 - 06:27 AM

#3

It does sound like a rocket. Curious how it would be on a MX track solely. I am sure it is a holeshot monster but wonder how the power would be long term in a 20min moto. I have a 03 Bigbore and although a blast for power it will wear you out quick....and thats when the mistakes seem to grab you. Maybe the 06 with your mods may be more forgiving.....but at what cost?
What $$$ did the carb and motor mods run approximately? Fun project it sounds like.....:thumbsup:

  • grayracer513

Posted April 17, 2007 - 08:17 AM

#4

I refer to the expert GR...Is this place legit in your estimation?

Ron Hamp, legit? Yeah, I'd say so. Stuff he builds runs in the Grand National series (that's flat track and TT, where horsepower IS an issue) and does well there. He has spent a lot of time working on cranking real horsepower out of theses engines, and is among a fairly small handful of people (another of whom, BTW,is Eddie Sisneros) who have been truly successful in pushing out the sides of the envelope. He built, for instance, a YZ250F head that by itself pushed the little YZF to 40 hp with no other mods except an aftermarket pipe. That means the head alone was worth at least 3 horsepower on a 15 cubic inch engine. When Ron comes out and says, "this is the best 5 valve head so far", it's worth listening to.

Think about that for a second; obviously, head work at this level will only produce the maximum benefit when you couple it with a complete, cohesive set of modifications, but consider that the power you get from a port job has no real downside. By that, I mean that the only strain it puts on anything is from transmitting the extra power. There is no additional strain on the valve train as there is with high lift cams, etc., or any other such side effect.

Reading CROGGR's posts, it's pretty obvious that he did the carb back in June, and more recently the head. This new one simply retells the earlier details.

  • black_n_blue_thumper

Posted April 17, 2007 - 08:27 AM

#5

It took over a year of testing and modding....but it is finally done and it's a rocket! I did everything one step at a time so I could record the performance gain every step of the way!




In conclusion, you can waste your $$$ on a lot of after market stuff and after market places that won't add much if any performance to your bike ( I know I've done it in the past) or you can have a world class engine builder build you a world class improvement! (RHC) Ron Hamp is the real deal!!! A big thanks to FFR (T-DUB) for all you help and getting me hooked up with RHC www.ronhamp.com .



So how much did you not waste on this project. :thumbsup:

  • twenty34

Posted April 17, 2007 - 07:55 PM

#6

Ron Hamp, legit? Yeah, I'd say so. Stuff he builds runs in the Grand National series (that's flat track and TT, where horsepower IS an issue) and does well there. He has spent a lot of time working on cranking real horsepower out of theses engines, and is among a fairly small handful of people (another of whom, BTW,is Eddie Sisneros) who have been truly successful in pushing out the sides of the envelope. He built, for instance, a YZ250F head that by itself pushed the little YZF to 40 hp with no other mods except an aftermarket pipe. That means the head alone was worth at least 3 horsepower on a 15 cubic inch engine. When Ron comes out and says, "this is the best 5 valve head so far", it's worth listening to.

Think about that for a second; obviously, head work at this level will only produce the maximum benefit when you couple it with a complete, cohesive set of modifications, but consider that the power you get from a port job has no real downside. By that, I mean that the only strain it puts on anything is from transmitting the extra power. There is no additional strain on the valve train as there is with high lift cams, etc., or any other such side effect.

Reading CROGGR's posts, it's pretty obvious that he did the carb back in June, and more recently the head. This new one simply retells the earlier details.


Thanks GR. I trust your judgement on this one so good to hear.

I guess my only concern and what was also pointed out, "Curious how it would be on a MX track solely. I am sure it is a holeshot monster but wonder how the power would be long term in a 20min moto. I have a 03 Bigbore and although a blast for power it will wear you out quick....and thats when the mistakes seem to grab you. "

Since the YZ prides itself on smoooth power delivery, I'd be curious if a head mod dramatically alters the ability to deliver the power. I'm all for more HP, but would be cautious if it altered the powerband dramatically.

  • CROGGR

Posted April 17, 2007 - 08:04 PM

#7

So how much did you not waste on this project. :thumbsup:


You'll have to contact Ron for pricing as it varies depending on model and what exactly you want done. Let me just say this however....for the increase in power that was achieved it is the best value there is and I would have gladly paid more!

grayracer513
Reading CROGGR's posts, it's pretty obvious that he did the carb back in June, and more recently the head. This new one simply retells the earlier details.

Thanks for the back up Gray you hit the nail on the head as usual! Ron has made some new break throughs on the Yamaha heads and are putting out more power as I can attest!!!:worthy:

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  • twenty34

Posted April 17, 2007 - 08:16 PM

#8

You'll have to contact Ron for pricing as it varies depending on model and what exactly you want done. Let me just say this however....for the increase in power that was achieved it is the best value there is and I would have gladly paid more!

grayracer513
Reading CROGGR's posts, it's pretty obvious that he did the carb back in June, and more recently the head. This new one simply retells the earlier details.

Thanks for the back up Gray you hit the nail on the head as usual! Ron has made some new break throughs on the Yamaha heads and are putting out more power as I can attest!!!:thumbsup:


How does this perform on a MotoX track where power deliver, not necessarily more HP is the key?
Thanks!~

  • CROGGR

Posted April 17, 2007 - 08:39 PM

#9

How does this perform on a MotoX track where power deliver, not necessarily more HP is the key?
Thanks!~


It performs fantastic! It's like comparing a 250f to a 450f. There is a lot more power everywhere so you need to be careful with the throttle! The power does have some advantages....at the local track here there is a triple jump that all of the 250f have to double single, the 450's have to rail the outside to clear the triple...not so with the RHC Yamaha, you can cut to the inside and still have plenty of momentum to clear it. You can even squid the corner and still make the triple!:worthy: It has that much more boost! And it is still smooth as long as your careful with the throttle! Soooo I can ride it like so and it doesn't get me tired......if I want to be entertained I can pull the throttle harder but then I get tired........work'in on getting in better shape now!:thumbsup:

  • black_n_blue_thumper

Posted April 17, 2007 - 09:15 PM

#10

You'll have to contact Ron for pricing as it varies depending on model and what exactly you want done. Let me just say this however....for the increase in power that was achieved it is the best value there is and I would have gladly paid more!:


Come on man, give us a ballpark. Please. :thumbsup:

  • grayracer513

Posted April 17, 2007 - 09:19 PM

#11

I guess my only concern and what was also pointed out, "Curious how it would be on a MX track solely. I ...wonder how the power would be long term in a 20min moto. I have a 03 Bigbore and although a blast for power it will wear you out quick....and thats when the mistakes seem to grab you. "

Since the YZ prides itself on smoooth power delivery, I'd be curious if a head mod dramatically alters the ability to deliver the power. I'm all for more HP, but would be cautious if it altered the powerband dramatically.

This is actually a very valid point, and it's exactly the reason that the civilized nature of the YZ450 results in faster lap times for so many people, and why so few people could really ride a 500 class two-stroke to its full potential.

A port job by itself is not likely to alter the character of the power curve, that is, it shouldn't add any sudden spikes in it, but it would "amplify" the power pretty much across the board. But that might be too much for some people's comfort level.

  • swatdoc

Posted April 18, 2007 - 09:43 PM

#12

This sounds very tempting to me for my 07 supermoto project. I have Rons valves, springs, and 187 cams on my DRZ400 supermoto, and can attest that it runs great. Head porting for the DRZ was gonna run another $600 or so, and my DRZ already is at 50hp, so I helld off on the porting. Also, the ported head requires oversize valves and the extra machining to install them. Extra flow then requires going from a 39mm carb to a 41. One thing always leads to another!
Ron definitely knows his stuff and is highly recommended.

  • Ron Hamp

Posted April 19, 2007 - 04:19 AM

#13

This bike had the basic port work and should be very manageable on the mx track what it does is let the bike be used a gear higher in most situations and uses a less agressive part of the curve it does not try to pull you off the bike .on hole shots it still has the power to over rev and distance the other bikes .there are new throttle cams also that make it so you dont open the throttle as quikly this may help it could also be a plus for the less agressive riders with a stock bike .im curently working on3 yamahas 2 for the grand national dirt track series with Henry Wiles riding and 1 for Ivan Lazzarini for the supermoto world title .

  • FriscoKLR

Posted April 22, 2007 - 12:08 PM

#14

Are you still able run pump gas with this setup (less the 13.5 piston). And are you runnning 50/50 race gas or more with the piston?

  • twenty34

Posted April 22, 2007 - 01:50 PM

#15

This bike had the basic port work and should be very manageable on the mx track what it does is let the bike be used a gear higher in most situations and uses a less agressive part of the curve it does not try to pull you off the bike .on hole shots it still has the power to over rev and distance the other bikes .there are new throttle cams also that make it so you dont open the throttle as quikly this may help it could also be a plus for the less agressive riders with a stock bike .im curently working on3 yamahas 2 for the grand national dirt track series with Henry Wiles riding and 1 for Ivan Lazzarini for the supermoto world title .


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