RB Carb Mods w/Fredette Porting & Head Mods

[green_passion]

After a whole lot of this~~~> I managed to talk the mechanic/Boyfriend into the RB carb mods.

However after he talked to Jeff Fredette he still dosen't agree with going with the RB mods (Jeff tried the RB mods and supposidly didn't *gasp* like them). So as a compromise, we've agreed on having the head mods and cylinder ported by Jeff and the carb done by Ron.

What's your experience with Jeff's porting & head mods with the RB carb?

[Ondatrail]

Jeff doesn't like the RB head mod because he won't make money if you send it to Mr. Black instead of him IMO. He's a buisnessman and what do buisnessmen do? make money. I haven't heard of FPR doing head mods before this but I've heard of no regrets from RB designs from tons of guys here.

[Colorado Mike]

I've never had anything done by Mr. Fredette, so can't comment. I have had work done by Mr. Black, and can't imagine such work being done any better. I would recommend you send the head to RB over Fredette, only because I have never heard a single complaint on his work, and you already have shipping costs for the carb, so you save there. Ron's headwork made a huge difference on my bike. So much, that now I would like him to do similar magic to the kid's YZ.

The notion that someone tried Ron's carb mod and didn't like it gives me pause. I could understand that if there was a penalty to be paid somewhere, such as poor throttle response in lieu of higher HP or whatever. In this case though, everything is better. What is not to like?

Beyond that, I still come back to thinking you are on the wrong bike. Desert (open) racing a KDX (woods) seems counter intuitive. Find a KX 500 and ride it just once in the desert and you will not waste another dollar trying to make the KDX do something it wasn't designed for. The KX will thrive in the desert where it's prodigious wings will let you fly. The KDX is more at home at sub-50 speeds, dutifully carrying you around or over technical terrain comfortably.

[green_passion]

Beyond that, I still come back to thinking you are on the wrong bike. Desert (open) racing a KDX (woods) seems counter intuitive. Find a KX 500 and ride it just once in the desert and you will not waste another dollar trying to make the KDX do something it wasn't designed for. The KX will thrive in the desert where it's prodigious wings will let you fly. The KDX is more at home at sub-50 speeds, dutifully carrying you around or over technical terrain comfortably.

I would agree with you except when I'm riding through the gnarliest rock gardens and hills and passing guys on 525's.

A 500 would tear me to pieces IMO.

The KDX has awesome grunt power that kicks ass in the technical sections that allows me to beat out the 13 year olds in my class. Just this last weekend on a nasty uphill, while the guys have their tongues hanging-out from exhaustion, I just zipped right past them on the mighty KDX. Plus being so light, it doesn't wear me out over an 80 mile race. Yeah on wide open stuff it just doesnt cut the mustard but I'd much rather have my 220 over any 4 smoker or 500 on the technical sections any day.

[Colorado Mike]

The KX 500 is lighter than the KDX, or at least seems so (but I think it is). Perhaps there's a misunderstanding of what I consider "Desert" riding. To me, it means "open". Anyway, the KX 500 I rode was very easy to ride. Maybe not quite as agile as the KDX, but certainly not a supertanker either. And, when I rode it I had yet to do the fork upgrade to the KDX, which made the KayDee gain a wider turning radius (and become a little less agile). At the time I thought the KX handled much better at anything greater than walking speed.

I think those that dismiss the KX 500 as some sort of tire shredding uncontollable animal without having ridden one, should try one. They might find that instead, it is a decent handling tire-shredding bike with a manageble motor that is almost electric in it's power delivery.

[green_passion]

Perhaps there's a misunderstanding of what I consider "Desert" riding. To me, it means "open".

Here's a preview/footage from last year of a desert race that demonstrates the rock gardens that we tyically race in.

Enjoy!

http://www.vimeo.com/648093/

[Colorado Mike]

sweet stuff . Looks like a big variance in the terrain, with some wide open stretches and the rocky stuff thrown in. I can see where the KDX could do well in the rocks. I can also see where it would get smoked by the big bikes in the fast sections. Gotta make the bumpy stuff count.

[bradf]

Ron Black is an expert in his field. That includes 2-stroke porting, 2-stroke head mods such as squish band shaping and carb work. RB carbs are not simple mods such as adding a divider plate to the intake or boring out the overall bore dia. RB goes far beyond the simple and easy and modifies all applicable circuits to work together. The superior results of an RB carb and head work are undisputable. I have talked to Jeff many times and I have seen his work and ridden the bikes. I would never ask Race Tech to comment on Jeremy Wilkey at MX-Tech. They are competing for business. But I do know who has more in depth suspension knowledge and that is who I use. My 220 ran with a virtually identical 220 except for the RB carb and heads with another 220 that had FRP porting and bored carb. My 220 had the SSS dialed in and there was such a difference that the other fella felt it immediately. He wasted his money. The RB total package where you can dial in the SSS is the bee’s knees. It’s sweet ass sweet.

[Jeb]

I've got the RB mods, and I can't for the life of me understand why someone wouldn't "like" them unless they prefer attributes other than lots more useable power. Maybe Jeff prefers more hit or something, who knows, but the RB mods are pretty awesome. There's no mistake on the performance improvements.

[scheckaet]

I'd say the same thing if I had a business competitor, the other one is not as good as mine...

[fuzzy]

Never heard of RB doing cyl porting, but I'd pick him over fredette. He's no engine builder, IMO. Ron's carb work is surely superior. Definitely let whoever is doing the porting do the head as they go together, and plan on running race gas so just go ahead and tell them that. If RB does your porting tell us all about it! If he doesn't do it I'd say go with Eric Gorr. He IS a very well known builder. Prepare for some minor jetting hassles after getting everything back...Things like needle profiles, etc that everybody runs on here mean squat after all that port/head work. RB will surely help you out there though....and make sure he knows what your doing when he does the carb/etc.

[green_passion]

I'm getting the RB carb mods done but waiting on the rest. We've agreed on having Eric Gorr do the porting and head mods for the bike. However we're right in the middle of the racing season so we've agreed to buy a '91 KX 250 for $250.00 and get it running for dirt cheap and I'll have a bike to ride/race in the meantime. With having the KX I can afford to wait the three-four weeks for the rest of the engine mods to be completed.

Although I know I'll miss riding my KDX.

I can hardly wait to try-out my bike once everything is done.

Thanks everyone for the advise!!

[Indawoods]

Ron turns them around in a week... you won't be waiting on Ron!

I would forget about the porting... I have never heard of a good porting job on a KDX other than factory. You can clean up the casting marks with a die grinder but Ma Kaw had it pretty dead on. The head on the other hand will benefit from Ron's magic. I don't know what it is but he has a way with the KDX.

[KarlP]

I'm with Inda on that, Ron does a nice job on the head.
With the head and carb done the motor will outrun the frame, that's for sure.
You might end up wanting to stick that now fine running KDX motor in the KX frame!

It never ends.......

[canyncarvr]

Lot'sa things.......

If Ron turns your carb around in a week..it's cuz he's been sick as a dog for 4-5 days. He's fast. Most of the stuff I've sent him is in his shop for maybe one day.

That said...DO get in touch with Mr. Black regarding his schedule and work load if you're expecting or needing your carb back SOON!!. 'Fer instance...I think Ron may be out of his shop this upcoming week. A bit of planning on your part may well forstay dissappointment on your part.

I had a cylinder ported by FRP. Long story short...don't do it. You're mechanic/Boyfriend is incorrect.

Do NOT let anyone touch that head other than Mr. Black. Please don't be stupid about it..do NOT allow it to go anywhere else.

Mr. Fredette didn't like the RB-Modified carb. He said it was 'too picky' to jet. THAT was back at a time when needles were still being sorted out..and I would bet you $$$ that Jeff didn't try the needles now generally considered to be THE choice with the modified carb. It was also before JD donated a lot of his time and knowledge to a determination of which needles worked. Canadian Dave took exception to Fredette's opinion as I recall (years back when this all came about). In this instance, Mr. Fredette is out standing in his own field.

Not that there's anything wrong with that!!

If you are not happy with one of Ron's carb..either your bike is jetted wrong..or you're just plain wonky yourself.

You can't beat it.

As long as your carby is there...DO get the finger adjustable air screw..and DO get his SS fuel bowl screws. I'd suggest buying whatever needle he doesn't put in your carb..a DEK or CEK so you can choose yourself which you prefer.

Have fun!!

btw...don't send in a dirty carb. Clean the thing!!! If it's not purty..clean it summore. You don't want any dirt around when the carb is being machined..and it's not Mr. Black's job to clean up your mess. Read what his website says...clean and no hoses!

Don't expect him to 'fix' someone else's problems. Asking him how to jet someone else's port/head work is not only not fair..but a completely unreasonable waste of his time.

One more thing..of course don't forget to send in the slide!! It's on the modification list.

btw#2..Very nice production on the video. The editor(s) know what they're doing.

[green_passion]

Lot'sa things.......

That said...DO get in touch with Mr. Black regarding his schedule and work load if you're expecting or needing your carb back SOON!!. 'Fer instance...I think Ron may be out of his shop this upcoming week. A bit of planning on your part may well forstay dissappointment on your part.

Already done! I will have my carb back by Wednesday of this week. You're right, Ron is AMAZING!!

We shipped it out last Wednesday and he had it shipped back out on Friday.

I had a cylinder ported by FRP. Long story short...don't do it. You're mechanic/Boyfriend is incorrect.

We are going to send it to Eric Gorr, not FRP.

Do NOT let anyone touch that head other than Mr. Black. Please don't be stupid about it..do NOT allow it to go anywhere else.

The thing is that we talked to Ron and he dosen't do cylinder work and mine needs to be replated. So we've agreed to go with having it ported to 225, replated and have the head done. Since the person who ports it is going to have to be the one to do the head mods we're going the Eric Gorr route.

Mr. Fredette didn't like the RB-Modified carb. He said it was 'too picky' to jet. THAT was back at a time when needles were still being sorted out..and I would bet you $$$ that Jeff didn't try the needles now generally considered to be THE choice with the modified carb. It was also before JD donated a lot of his time and knowledge to a determination of which needles worked. Canadian Dave took exception to Fredette's opinion as I recall (years back when this all came about). In this instance, Mr. Fredette is out standing in his own field.

Not that there's anything wrong with that!!

If you are not happy with one of Ron's carb..either your bike is jetted wrong..or you're just plain wonky yourself.

You can't beat it.

As long as your carby is there...DO get the finger adjustable air screw..and DO get his SS fuel bowl screws. I'd suggest buying whatever needle he doesn't put in your carb..a DEK or CEK so you can choose yourself which you prefer.

All of which have very valuable opinons! Thank you for the information.

BTW - I did buy the air screw with my carb mod.

Have fun!!

btw#2..Very nice production on the video. The editor(s) know what they're doing.

Thanks! I'll pass along the compliments to the guy who made the video.

Again, thank you for the information!

[Ondatrail]

Do NOT let anyone touch that head other than Mr. Black. Please don't be stupid about it..do NOT allow it to go anywhere else.

The thing is that we talked to Ron and he dosen't do cylinder work and mine needs to be replated. So we've agreed to go with having it ported to 225, replated and have the head done. Since the person who ports it is going to have to be the one to do the head mods we're going the Eric Gorr route.

Head not cylinder

[scheckaet]

Head not cylinder

?

[fuzzy]

You'd have to ask RB, but I'd say whoever is doing the 225cc overbore and port work needs to cut the head. EG knows what he is doing. I will say this from what I've heard...Plan on the need for race gas even if you specify pump gas. SOmething about the 225 and how the head ends up seems to require it (maybe only a small %). If race gas isn't a problem then going ahead and specify that you'll be running it, and it will get cut more aggressive(more power).

[Ondatrail]

Head not cylinder

?

CC's saying to send his head to RB not FRP. Green Passion is explaining thier cylinder.