01 200 Bottom End - Porting & Head Work

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T-Roy
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01 200 Bottom End - Porting & Head Work

Post by T-Roy »

Hello Fellas!

I'm looking to go from a rev setup to a torque setup. I currently have a 200 with a rev pipe, Ron's carb work, 607's, no porting or head work, and stock gearing. In the near future I'm going to switch to a torque pipe, and then fiddle with the gearing a bit.

Now, for the big questions, what are your thoughts on boring (ala EG 225), porting and/or head work? Where are the biggest bottom end gains for a 200?

Options:

1 - EG 225 Kit with low end porting
2 - FRP or EG porting, no head work
3 - FRP or EG porting and head work
4 - FRP porting, RB head work
5 - RB head work

Pro's and cons of the 225 kit? Will porting alone make a noticeable diff or would Ron's head work be a good start? If I had Ron's head work done does this mean that I screw things up for a later 225 overbore? Would I be better off with FRP porting and Rons headwork or let EG do it all? What combo's of porting and head work do you guys have?

Your comments and recommendations are greatly appreciated!
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Post by motorider200 »

I'm running the eg 225 kit with mobetter everywhere porting and ablosutly love it. It pulls harder everywhere with the biggest gain in the midrange. Some people including myself have had to run race gas after the mod do to detination.
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Post by skipro3 »

From what I hear, the EG is the way to go. My riding bud's KX500 rocks in the torque area after this mod. Others here may jump in and tell you their experiance with the FRP. I would stay away from that one if I were shopping for a port job.

To help overall torque, here are a few suggestions:
1. Steahly flywheel weight
2. 12 tooth countershaft sprocket
3. RB-Designs modified Air Stryker Carb
4. V-Force III reed kit

Not in that order, and I note you might already have some of this work done, but I recommend only making one change at a time. Otherwise it could get real confusing!

I have a reshaped head from Ron but since he custom shaped mine for a 220 running at altitude and using race gas, my experiance won't be much use for you. I do love Ron's work though on the head. I've never had any problems with it.
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Post by farmerj »

I haven't got experience with porting, but V-Force reeds outshine the Steahly FWW for getting what you want, IMO. I mean, you may want both - but the DF II provided the torque I wanted (and crisper revving, and less "4-stroking"). Can't wait to install my DF III!

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Post by skipro3 »

The Steahly FWW helps keep the bike from stalling during those low speed lug situations we all know so well. If you have any problems with the bike stalling during heavy braking, for example, the FWW will help out there.
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Post by farmerj »

skipro3 wrote:The Steahly FWW helps keep the bike from stalling during those low speed lug situations
I agree, and also on downhills...

Jeff
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Post by T-Roy »

CC, I would really like to hear your opinion. Which combination would you go with based upon your experiences?

I really would like to give my biz to Ron but I'm unclear on the porting aspects. Would I be hosed if I had Ron do the head work and then wanted to overbore to a 225 kit later on?

Thanks for taking the time to respond.
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Post by IdahoCharley »

I don't believe that if RB does the head and then later on you want to go to a 225 displacement that you have real concerns.

When, or if, you decide to increase the bore size the head needs (should be) to be matched to the cylinder bore size anyway; essentially RB or EG would be extending the outer edge of the squish area another millimeter or so to match the new bore. (EG used to do this as a part of his big bore upgrades and it was figured into the price of the big bore - if that matters to you)

I can contribute nothing to your porting questions concerning the KDX but I have had EG port a couple of cylinders for me and was pleased with the results. (KTM/Yamaha/Kaw(100) cylinders)

I'm also very pleased with RBD head modification on my boy's KDX 200 and would recommend it.

BTW - I read something about EG closing shop for a few months to relocate to a bigger/different facility. If you are thinking about the modifications in the next couple of months you may want to check to see if I'm blowing smoke or not.
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Post by canyncarvr »

re: Will I be hosed?

Don't know about hosed, but probably not a good idea.

The head has to be reconfigured on the big-bore...its volume is increased. That's opposite from what is going to happen if you get it reconfigured for use on your 200. At some point..taking metal off to decrease the volume (the 200) and taking metal off to increase the volume (the 225) you're going to run out of metal. I do not know from having done both, but I would decide what I was going to do and have the head reconfigured once.

It's a matter of what you are expecting, what you want.

I have an FRP ported 200 cylinder..done with the instruction of, 'Do nothing that will decrease bottom end response.' My intake/transfers changed considerably, the exhaust was left alone. My bike detonated something awful when I got it back. Bad enough (I figure) to blow one of my KIPS drums completely out of the cylinder! I sent my head to Ron, asked him if he could help solve someone elses problem. With his head work, my bike detonates less, runs better, but I still have to run an octane booster.

As already noted, bikes with the 225 mod specified to run on pump fuel have indeed ended up requiring something other than pump fuel.

The decision to not go the 225 route for me was the widely reported decrease in range with that mod. I often need 70 miles+ per tank. Dropping that to maybe 50 would make my bike a complete PITA to ride most anywhere.

Keep in mind that a port job will (should) be followed by a replate. THAT is problematic. I've got more problems caused by my replate than I want to deal with. I've not had 15 cylinders replated to have any sort of 'average' take on what happens, but in my case USChrome screwed the pooch (bow-wow!).

The biggest bottom end gains for a 200?

I can tell you what worked in my case (not in any particular order):

An RB-modified air stryker carb tuned to the SSS (Yep. It matters!)
An RB-modified cylinder head
FRP ported
DF3 reed valve
12T CSS
5-10% (by volume) toluene in your fuel
-EG plug gapped to .030"
Light coil (yes, you read right)
Maxima SuperM

If you haven't tried toluene, you should.

BTW, I run a -30 pipe (rev), too! It was Ron's carb work combined with my DF3s that got me to the place I could use the -30 in the woods.

Premix oil matters. If you are not using a very good, reliable oil...do so.

I'm sure the 225 will give you an improved lower throttle range. If I didn't care what happened to my range, that likely would have been my choice.

Good luck!!

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How the heck do you...

Post by Mark W »

blow the KIPD drum out out the cylinder head? somehting blow-up?

Also, I know this is a little late but waht is the squish band and what does Ron's work to the head do to improve it? I know I should have asked this last question prior to Ron completing some work on my head but I m curious.

Mark
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Post by fuzzy »

If you're gonna get an EG 225, then certainely let him do the head/port work. I don't think he would even do the 225 w/o having your head. From what I've heard I'd never let FRP touch my cyl. EG knows his stuff, and is a dedicated engine builder.
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Post by canyncarvr »

This is anecdotal..take it FWIW.

Mr. Gorr has been quoted as saying Mr. Fredette knows '...all the secrets..' when it comes to KDX porting. I've not personally seen that in writing or heard it from anyone I know.

I'm not thrilled with my FRP'd cylinder..but I do not know exactly who is responsible for what. The porting is an improvement...but if I'd known beforehand that the performance gain included spatter out the S/A that makes a complete mess of everything, that has me repacking my S/A every couple months, ruining $100s of dollars of riding gear, making after-ride clean-up a bigger PITA than it needs to be...I wouldn't have done it. But, as tuning and efforts trying to resolve the spatter continue I am moving ever more close to skipro's point of view..it's a USChrome problem.

I'll resolve that question, too. That's why I spent $350 on another cylinder.

Something blowed up?

Mark: Where 'ya been? :wink:

Take a look at this. to find out about blowed up stuff.

Actually...you posted to that thread. But, yes..that is what blowed up. Broke it, blew it clean out. That pic is from the ported cylinder. The KIPS worked fine when the cylinder was installed, but the drum didn't last long. My guess is the detonation I've had since the port job (generally I run toluene..I didn't use it at first) is responsible. THAT is a good part of my 'not thrilled' part with my porting job. Yes, I've been back, forth and sidewise on every carb circuit and in different combinations...the detonation is NOT a jetting issue.

What is squish:

Mark: Where 'ya been? :wink:

Check thisfor a pretty good understandable write-up on squish (and quench). Yes, I realize this is a 4-stroke article and that quench doesn't have much to do with a hemi-headed 2-stroke. Search the page for 'squish'...it's a ways down the page. Google 'squish cylinder head' and you will get enough reading to keep you going for awhile. Basically, squish is the most important factor in cylinder configuration. It's more important than static compression (volume) sez me.

I didn't go looking for this one, but there is a quite good thread on this board about squish and what it does...why it matters.

As noted above, Ron increased the combustion pressure in my engine (increased compression/reduced volume) AND reduced detonation at the same time. THAT comes from knowing what you're doing! THAT is squish-magic!

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Post by Mark W »

Thanks for the links.

Would spark plug indexing then be a further benefit for squish? I mean would indexing help squish achieve what it is trying to do "better"? Interesting.

I've been around here lurking a few times/day. I'm in-between jobs and have much time to kill lately. Just took a new job this morning as a matter of fact in the Mining area. Should be significantly different than the boat/ship building market. Made a couple of posts and added a couple of jokes.

Still waiting for the weather to turn here so that I can get my "new" bike out on some dirt. I was too afraid to do any of the real breaking in of the new piston with the weather being as cold as it has. I have run the bike through 4-5 warm-up cycles blipping the throttle a little just cause I'm anxious. The new pipe sound will take some geting used to but not the new throttle response - I love it. Twist the throttle and the bike actually responds.

Suppose to be 50 here tomorrow and it might be a good time to do the first copuple of warm-up rides for break - in. I figure a visit to the folks place with my son riding his bike might be in order. Repacked his silencer and am wondering how I could've messed it up. Will find out later today or tomorrow.

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Post by canyncarvr »

re: indexing..

Where 'ya been!!?? :wink:

...OK..now that's just irritating....

There has been some discussion about that, too. Cliff's notes version: Indexing is more an issue with 4-strokes than 2, and with 4-strokes that have something other than a hemispherical head.

A spark plug (on a lot of bikes/atvs) sits right at the top of a hemi head. The direction the spark 'faces' isn't as important as a non-hemi head which (by definition) has quench spaces, irregularly shaped spaces. In the latter case, the direction the spark 'faces' may well make a good bit of difference.

I do recall there is a preferred spark direction even in a 2-stroke...I am not sure where that is, but I think it's toward the rear, between the pairs of transfer ports.

It's an academic issue, imo. Go to the trouble of spacing your spark plug and indexing if you like.

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Post by KDXer »

RE Indexing: I had a go at getting the plug facing the rear. I had to use a very, very thin washer to do it. I don't know if it will make any difference due to me installing the new head and carb at the same time. Why did I do it you ask ?!?!




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