RD400F cockeyed video 1st run Vertex 66.00

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Rebuilt top and bottom end. RT side took a bit of the piston, found airleak not only at base gasket, but particular to Daytonas a case leak right where the actuator rod goes. Right cylinder looked toasted w/ a big chunk taken out of the exhaust on the left side. Took to Superior Sleeve and he said, lets see if it will clean up (speaking above exh. port damage). I figure 75 bucks not a lot to spend and if no good, i have spare cylinders. So w/o any pistons, he says the bore cleans up at 66.00mm and the damage below the exh port isn't a problem. Initially, if i had no damage, I would want the piston clearance to be .0017~002 for vertex. I decided the use the 66 mm Vertex (about 3.5mm cut off all the way the base for the 400) and I'm thinking the clearance is a bit fat around .0023", but hey, probably won't cold seize it and didn't want to waste a set of pistons...if this goes south, i'll bore to last 66.50mm.

So being that i jetted this thing months ago w/ an airleak at the base gasket and a case leak 1psi lost in 2minutes.....i don't know if I'll have to rejet. I basically run this a bit fat in the pilot for smooth cruising usually. Now that the bike holds air (passed the pressure test 7.5 psi for at least 2 minutes steady...good enough!).

I decided to take a video for others to review and comment. I often struggle w/ jetting and w/ custom BANSHEE divider plate carbs (RB Designs) adds another dimension. Carbs are bored to 28mm, dynojet III needles on the 5th clip i believe, 360 main jet, 27.5 pilot, stock slides and i believe a 1.6m airjet, that i can change if needed(threaded). 66mm Vertex pistons & H2 small end bearings-w/ a generous clearance (more than i like, but i'll try .0023), YZ125 reeds, banshee intakes/x-over, Y-boot K&N, Spec II classics expansion chambers, timing 1.9 BTDC, 92 octane pump gas (ethanol), premix 32:1 currently on honda GN2. Heads are set to .040 clearnce, stock 14* angle and stock 120 psi, o-ring sealed.

Anyway here's the video...at least it cackles smoothly on steady cruise. Sorry for the sideways view, but no mount, just tie wraps to my backpack.

V I D E O!!! ---> https://www.youtube.com/watch?v=nZGK2md ... e=youtu.be" onclick="window.open(this.href);return false;

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found some notes going between pistons from smaller (TKRJ) to larger (vertex/prox) windows. 1. 1 size smaller main 2. richer clip setting 3. 1/2 turn leaner on the airscrews. Think i'll try a smaller main and leaner airscrew first and see how that works out. Dynojet needles have 6 clips right?

[mkane]

That shifts with the linkage out of whack like that.

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i need some shims made up...yeah, it whacked, but it works. shifts easily actually. A lot easier than motocarrera 1st gen rearsets on the RD350! Ron (RB Designs) could make me some or look at it and find a solution

Took the carbs apart to see what my baseline was. 360 mains, Dynojet III full rich, 1.6 airjet & 1-1/2 turns on the airscrews.

Well I think my notes are working for me. The airjet leaning was a positive. Found out the dynojet needles are indeed rull rich. Dropped the main jet from 360 to 350 and it sounds more like the bike did before the piston fragged. Now that I have a good sealed motor, looks like a rejet again. I am now at 2 turns out on the airscrews and I believe it is still a little rich down low. Going to try a #25 pilot from 27.5. believe the pilot is carrying over and muddying things up a bit.

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Update: 330 main / Dynojet III-6 clip / change from 2.0 slide to 2.5 "cut" slide (good/positive change) / 1.7 airjet from 1.6 (better) / #25 pilot going to try 1-5/8 from 1-1/2 on the airscrews. Changing to the leaner slide helped w/ the richness between 1/8th~1/4 throttle. The 1.7 airjet helped a even more. What I really need to do now is a main jet plug chop!!

The only thing i might be thinking is maybe cutting the slide some more?

Still sorting, but not too bad.

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Well messing w/ the airjets didn't have much benefit, leaned out the mids. So far the real positive i am getting is w/ slide cutaway for the 1/8th to 1/4 richness. I am going to see if RB Designs can cut me a slide to 2.75 cutaway. Going from 2.0 to 2.5 was better, but i think i need more like Spec IIs carb did. The 22.5 pilot wasn't good either, so back to the 25 pilot. I think if i can get the cutaway right that will be 90% of the battle. Wish me luck.

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I think I'm about done jetting this thing, hallelujah! RD400F / banshee carbs 28mm bored , so there is no confustion here!

330 / Dynojet III-6clip / 2.75 slide / #30 @ 1.5 / 1.6 airjet (32:1 premix) and a change to Y-boot UNI filtration (my fave). 1/4 throttle is much better now. Holds partial throttle decently up slide grades now and acceleration is dam good for a stock (120 psi )compression motor w/ right side lower port damage (potato chipped piston from previous bore) (above the port is not a problem and that cleaned up w/ fresh bore). I guess it doesn't hurt to run redline race synthetic either...nice smell...almost like castor.

about friggin time. So the stock slide had to be cut from a 2.0 to 2.5 and finally to a 2.75. This, in turn made the pilot leaner (in my haste didn't try the richer pilot), so i had to go richer. RB told me about the tradeoff of circuits and that this would probably happen. I ran a #30 pilot on my r5 carbs, so that's what i put in. Needle full rich was the only sure constant. The 330 main feels definitely ballpark and pulls 3/4 to WFO.

I think i can actually take it on a long ride w/ some confidence now.

[Vintage Smoke]

I can't believe you are still writing multi page jetting posts and still blowing this bike up!!! lol
Kev...at least you are consistent!!!!

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These are another set of carbs. I wore out my R5 carbs (over 60k miles!). Ron modified some banshee carbs for me w/ divider plates and i had to choose from 5N7, 5L1 (7 clips) & the Dynojet needles. Ron bored these out to 28mm. I'm like oh no, another set of unknown carbs...where do i start?!!


Guess what, i had a case leak this time! right where the actuator rod goes through. Ron had dealt w/ this before and he sealed that are up for me.

So when are you gonna let me come back to 2SW?

And I've been eyeballing the RZ bearing install billet thing you have. Too bad no daytona rearsets. My spec II rear sets are getting sloppy.

I just took it out today. 330, then 340 mains, the 320 mains feel much better in the banshee carbs, too bad I can't D.F. these things...would have been A LOT easier to tune.