All back together

[crazybrit]

Just put the bike all together (new RB carb, RB head and new Wiseco piston).

Gonna ride it over to the offroad area Saturday (I live in the city and the cops hang out at the Starbucks 1/2 block away) and do a 20 min upto-1/2 throttle run, cooldown and then a 20 min upto-3/4 run, cooldown, then a gentle ride. Whats the cooldown, 30 mins ok?

Also, Ron recommended removing the airbox cover. I was talking to CC and he said some bikes have an unused hole in the frame nearby. I couldn't see anything so maybe my 98 doesn't. I'd prefer to secure the CDI with a bolt somewhere rather than ziptying it. Anyone done anything ingenious? Got a pic?

Failing this, anyone got an airbox cover (drilled is fine) they don't want and would sell? I have reasons why I'd rather keep the old cover undrilled. Thanks!

[crazybrit]

Well. I did two short heat cycles on my driveway. Sunday trucked it over to the off-road area, did a 20 minute break-in, 2 hour cool down followed by a 30 minute break in.

The last time I rode the bike it was a bone stock 220R (last fall). Injury and wrenching since then. Stock 220 piston was according to Ron at the end of it's service life.

Now it has a new Wiseco, rev pipe, 607 reeds, fully opened airbox, RB carb mod and RB head mod.

It didn't seem a lot different power wise or responsiveness wise. I was kinda expecting a dramatic difference.

I checked the compression, 152psi which is right at the upper end, so I did the top-end correctly.

The bike wasn't a slouch, my friend on a DRZ400S had to get on it to keep up but like I said, didn't feel that different.

Ron lives 5 miles from me and set the carb up for this area, it was stalling when coming to a hard stop and wouldn't kick start, only push would get it going, plug was oil wet so I appear to have some jetting fine tuning to do still but I must be fairly close.

I pulled the stock silencer and tomorrow I'm going to run some compressed air through and see if it's blocked up.

Any other ideas? I guess I need to hook up with someone who's got similar mods, maybe the year I was off the bike has erased my memory banks. Dunno.

Tony

[2001kdx]

Look near the front of your left side panel for the 'hole'. That's where my CDI is ziptyed.

[crazybrit]

Look near the front of your left side panel for the 'hole'. That's where my CDI is ziptyed.

I ended up just cutting out the center of the airbox cover, the part where the CDI mounts is still there, but it's pretty wide open. Turns out a new cover is only like $10.

[RBD]

Hey crazybrit,

It sounds like there is something really wrong here...., you should have had a big differance...???

How did the bike run in Febuary when you first had the carb done? I know that you just did a top end job and replaced the piston along with my head mod last month.

Am I missing something here, or are you just now trying the carb and head mod for the first time?

One of the first things to try is checking for any air leaks; reed block, carb manifold, base gasket.

I am here to help..., let me know what I can do.

Ron

[crazybrit]

Hey crazybrit,

It sounds like there is something really wrong here...., you should have had a big differance...???

[/qupte]

I don't sense one.

[qupte]
How did the bike run in Febuary when you first had the carb done? I know that you just did a top end job and replaced the piston along with my head mod last month.

Never rode it. CC scared me into doing a top-end because the bike (with new increased power) was gonna explode with the stock piston.

This is my first time out since last Oct. So literally, I have a new piston, new pipe, new reeds, new carb and new head.

Am I missing something here, or are you just now trying the carb and head mod for the first time?

No, you're not missing this fact. I should have ridden it with the stock piston (and the new carb, head would have been tricky ;-) rather than being scared into believing it was a ticking time bomb. I volated #1 engineering rule, make one change at a time or as close to that as possible. This is 100% my fault.

One of the first things to try is checking for any air leaks; reed block, carb manifold, base gasket.

How do I check for this. I have to say, it doesn't feel any worse than the stock bike.

[2001kdx]

new Wiseco, rev pipe, 607 reeds, fully opened airbox, RB carb mod and RB head mod

You added all of this and you can't tell a difference - Somethings up

[crazybrit]

new Wiseco, rev pipe, 607 reeds, fully opened airbox, RB carb mod and RB head mod

You added all of this and you can't tell a difference - Somethings up

I agree. I 100% agree. I've ridden 200EXCs. I know how the KTM hit feels. I wasn't expecting this but I was expecting some change.

[m0rie]

What jetting did Ron send back with the carby? What oil and mix ratio? Fresh plug and properly gapped? Fresh gas?

[crazybrit]

What jetting did Ron send back with the carby? What oil and mix ratio? Fresh plug and properly gapped? Fresh gas?

I'll have to go check the jetting specs. Ron's like 5 miles from me, so I picked up the carb. There are no aspersions being cast here. Ron has helped me w/ my KTM plus the KDX and if I ever need more work doing or I hear of anyone who needs machine work, I'm sending them pronto over to his place on Thompson. This is 100% a problem at my end. Either bike or in my head. Ron helped me way more than I deserved or paid for,

Running 40:1. I used to run 50:1 but Ron recommended 40. Plug is maybe 4 rides old. I gapped it when installing but have not rechecked. Yes, fresh gas.

Bike would pull in 1st and the bike would run out of stream fast (as before). It has power in 2nd-5th, make no mistake, it CAN get out of it's own way but it didn't feel to me to be any major improvement over stock

Before I bought the bike (all stock) I test rode a bike with an FMF (otherwise stock) and it just ripped. Front wheel wouldn't stay on the ground, though I was test riding on pavement not dirt. Guy changed his mind on selling it.

[m0rie]

Check the jetting specs and let us know. Could be a piece of something in the main jet plugging it up. You did remove the duck bills on stock reed cage when you swapped to the 607's?

[m0rie]

Do you remember if Ron put the CEK or DEK needle in for you?

[crazybrit]

Check the jetting specs and let us know. Could be a piece of something in the main jet plugging it up. You did remove the duck bills on stock reed cage when you swapped to the 607's?

Duck bills? The metal holders? Yes, replaced (as per instructions) with the ones in the 607 kit.

OK, pulled the spec sheet.

mixture, 7/8 turn out
needle, CEK-3
pilot, 40
main, 150

RB mixture screw installed. [I didn't mess with it as I was more focused on completing breakin, plus I couldn't find the printout on how to adjust ;-)]

What Ron removed (wow, nice documentation, thanks Ron!!!!!)
Needle: 1174
Pilot: 48
Main: 140

Sunday was overcast, drizzle, maybe 60 degrees, riding at ~1700 ft.

[2001kdx]

Wow, Ron went 3 sizes down on the pilot and 4 sizes up on the main. That's a huge difference. I can only assume this is a 220 from those specs. Did you inspect the carb yet? I'd pull that baby off and have a look. Other than that, I have no clue.

[crazybrit]

Wow, Ron went 3 sizes down on the pilot and 4 sizes up on the main. That's a huge difference. I can only assume this is a 220 from those specs. Did you inspect the carb yet? I'd pull that baby off and have a look. Other than that, I have no clue.

Yes, see post #2. It's a 220. 1998, I'm the 3rd owner.

Doh! Forgot to mention, the carb came from a 200 I got off eBay. I bought it for Ron to modify rather than modifying my existing one. The old values are clearly totally pointless/irelevant, I forget where the eBay seller was located, somewhere far from me.

Sorry about that brain fart. I still have the original 220 carb (unmodified), tomorrow I'll pull it apart and verify how it's setup.

Ron said the 200 carb looked fine before he bored it out.

[crazybrit]

Gonna take the bike out again Friday. Probably same location, ~2000ft elevation. Browns Camp, Oregon. If anyone has any ideas on what to check other than verifying the silencer isn't blocked, which I'll try and do tonight, I'm all ears.

Here is the carb info:

New RB Carb: Came from a 200. Bought it on eBay. Ron said it checked out ok and he set the float level. Previous info on old setup (Needle: 1174 Pilot: 48 Main: 140) is totally irrelevant.

Setup currently as: needle: CEK-3 pilot: 40 main: 150

Old carb: That I was previously running. From stock 220R. 42 pilot, 145 main, needle R1173L (clip 2nd position from top [2 of 5]).

[80elkster]

You mentioned that you did not touch the airscrew, well you need to touch the airscrew. Did you buy the knurled finger adjustable screw from Ron? Even if you didn't, warm the bike up fully, by riding it (don't be bashful ride it hard, those rings won't seat if you baby it) then turn that screw in a 1/16th of a turn and ride it some more. If that didn't change anything try turning it out an 1/8th of a turn, follow Ron's instructions and search for the Second Sweet Spot. Try blipping your throttle all the way open, if it bogs then try and adjust the airscrew until the bog is gone then take it for a spin you might be surprised.
P.S I allways kept a small screw driver jammed in the foam of my cross bar pad to adjust the airscrew before I got the finger adjustable one from Ron. I fine tune the carb every ride since temperature makes such a difference and believe me it's worth it!!

[crazybrit]

You mentioned that you did not touch the airscrew, well you need to touch the airscrew. Did you buy the knurled finger adjustable screw from Ron? Even if you didn't, warm the bike up fully, by riding it (don't be bashful ride it hard, those rings won't seat if you baby it) then turn that screw in a 1/16th of a turn and ride it some more. If that didn't change anything try turning it out an 1/8th of a turn, follow Ron's instructions and search for the Second Sweet Spot. Try blipping your throttle all the way open, if it bogs then try and adjust the airscrew until the bog is gone then take it for a spin you might be surprised.

Yes. I know I need to. I was more focused on correctly breaking in the new top-end. I realize I need to adjust it but right now the bike feels about the same performance wise. It'll make this much off a diff?

I couldn't find the adjustment instructions but I just found them and made a photocopy to take with me Friday. So yes, I know I need to do it

- Start the engine and let it warm up to operating temp with the bike in neutral blip the throttle from the closed position and see if the engine
- stumbles or stalls

- Adjust the mixture screw in one direction only a 1/16th turn at a time Blip the throttle, if it improved, turn it about 1/6th turn and blip again.
- If the direction you first started with makes worse then turn it the other direction 1/16th turn at a time until you get the best response

Ok, the above makes perfect sense. It's the rest I'm a bit confused on.

- Next get on the bike and run it in gear with the engine idling and blip the throttle. Then try and adjust the mixture screw 1/16th turn in both
- different positions till you get the best acceleration off a closed throttle

blip the thottle. I assume clutch is out and I'm chugging along slowly with the motor idling? How is this related to the later best acceleration off a closed throttle, or this just another way of saying 'blip the throttle'. Am I trying two different things here, or just one.

- Finding the second sweet spot is similar, turn the screw out 2 1/2 turns and do the same fine tuning procedure as above. It's a little tricky
- funding it and even a 1/16th turn can go right past it.

Whats the second sweet spot? Is this the above blip throttle in gear? I assume this is the second, and the bike in neutral is the first. In which case I don't get the absolute 2 1/2 turns out comment. If I'm just turning 2 1/2 turns, whats the point in doing the first adjustment?

[canyncarvr]

It's going to get real confusing to address this item by item. This is kind'a an overview...a restart.

Air screw adjustment is generally this: Adjust to high idle. 2 1/2+out? Pilot too big. 3/4-out? Pilot too small.

That doesn't apply to an RB modified carb.

Adjust for the best throttle response. That determined thusly: Walking speed, bike under load (an incline..drag the rear brake a tad), 2nd gear, twist from off idle to about 3/8s throttle..adjust air screw to obtain the best response.

You will find that best response with that test method to be in various air screw spots depending on lots of things..basically environmental input and your current jetting setup.

Call that setting the Sweet Spot. The spot that works.

There is a Second Sweet Spot (SSS) on an RB modified carb. Because it historically has been found on either side of the 2 1/2 air screw setting, THAT is why you start at that point.

Best way (imo) to test for the SSS is in 3rd gear. It's evident other places, but 3rd gear really comes alive! You will feel it in a lower RPM range than you would generally even run 3rd gear. The bike will pull harder starting at a lower RPM and pull well through a higher RPM . With the bike set to the SSS you will find yourself running in a higher gear than you used to use in the same places...and that will mean running a considerably higher speed.

As stated, don't adjust too far too fast. 1/16 turn can indeed take you right past it.

It's there. 200 and 220 riders have found it..and love it when they do.

You will get used to how your bike reacts to simple things...temp changes for instance. You will know which way to tweak your airscrew..it will get to the point you can tweak it on the fly!

And until you DO find it, you will think it's largely a pipe-dream..and SURELY can't be that big a deal.

You'll change your mind..........when you find it on your bike

What's the point of doing the first adjustment? It's a starting point..easier to get set. Once you go to the tweaking required to find the SSS, you will keep it there.

[crazybrit]

Thanks Brad. I really appreciate the explanation. Heading to Browns friday so I'll give it the old college try.