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Took my r1 7 for a drive today where I got out of first gear. Super exciting to drive! Having a lot of issue with light throttle bucking. Too much timing? Lean condition? I am running open headers which could be causing the fueling to be off.

On a side note, the clutch and throttle need to be a bit heavier (added springs). Source for reliable springs?

Mcmaster sells many kinds of springs suitable for pedal returns.
You can also make your own springs with a vice mounted jig and music wire.
Springs should only be used to counter the pedal system weight.

I would first look at utilizing full, disconnected pedal travel(should have an adjustable stop. 45deg sounds reasonable) over the range of cable movement using the bike throttle butterfly bellcrank and clutch arm if cable or if hydraulic, compare clutch lever full travel with open bleed to 45 deg clutch pedal travel. You can fit a larger bore master for better clutch feel and higher effort.

The loss of the cush drive can make it seem more sensitive also but start with the basics.

If you want to share, post some pics?

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Sounds like a pretty typical BEC. A light flywheel with not a lot of inertia mated to a heavier vehicle will do this.

_________________
-Andrew
Build Log
Youtube

R1 in a 7, first gear bucking is pretty normal.

Install a Barnett spring clutch kit or slipper clutch and it's more driveable

_________________
Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216

Clutch is cable operated. It's very light. I pulled the clutch too far before the first drive and it stuck the clutch disengaged. Needless to say that I immediately made a clutch pedal stop. Don't ask how I got it unstuck.... Throttle pedal pedal needs one too, but it's not an emergency as I'm nowhere near ready to floor the thing.

Miatav8, are you saying I should not add spring to the throttle pedal for a heavier feel?

I was guessing that this would have some driveline lash but it gets amplified by the light throttle pedal when my foot starts to bounce against the pedal. A "heavier" pedal would help this.

Slipper clutch would soak up some of the lash? What does the Barnett spring kit do?

None of my pictures seem to be small enough to upload. That normal?

Yes. Thanks for posting pics but I was hoping to see the throttle and clutch pedal system. It appears the throttle cable is barely long enough for the routing.

A rising ratio from idle to WOT will make the throttle less sensitive off-idle but still provide WOT. A quadrant or quarter moon shaped ramp for the cable guide can provide this. The center of the moon rotates at the same rate as the throttle pedal.

At idle, the cable end is closest to the moon center of rotation and closest to the firewall/cable sheath stop. Compare to a cam lobe on the base circle.

As the throttle increases, the lift increases so at full pedal travel, WOT is achieved.

The rate of lift increase cab be slow in the first third to half rotation then rapidly reaches full lift/WOT.

You can make this lobe/quadrant out of aluminum or bent brake tubing. Just need a smooth groove with guides to keep the cable in the groove.

This non-linear pull device can also be inline versus built into the cable.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Yeah, I figured you wanted to see that but I didn't have pictures of that area and was watching the little ones. Funny, I can't see the pics anymore.

Yes, I could use a lobe to decrease sensitivity at low throttle. Not a bad idea. The throttle is a very direct run already but if I don't have the space or excess cable, I could always build the lobe with a pull and with a short link to the pedal.

I have a bunch of other tasks before I sort this one. Panels, floor, exhaust, and electric reverse are next.

The Barnet spring kit gets rid of the Belleville spring thats standard on the R1 and replaced it with 6 or 8 coil springs, I don't remember, but I think 6.

The coil springs provide 3 things
1. they don't invert and stick disengaged like a Belleville spring will do
2. higher clamping force
3. firmer pedal feel.

You can get firmer pedal feel a few different ways, but man o man what a difference the Barnet kit made in my R1 car.

_________________
Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216

Did you also use a slipper clutch? Does it affect engine braking to a large extent?

Once you mentioned this I did a bit of searching on the r1 boards and there's talk about successfully using a second diaphragm instead of swapping to Barnett style. Just another interesting option.

I didn't add the slipper on this car, but did in helping a friend do his. He's put about 10,000 miles on the car since making the change and loves it.

I've read about double disc belleville. You get firmer clutch feel, but no increase in clamping force. It doesn't prevent inversion either.

_________________
Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216

MS paint allows saving a pasted pic as a jpg. Maybe that is the issue?
Best size is 600x800 if memory serves.

I believe ccrunner also added a barnett spring kit to his Berk with vfr800 power.

You should still maximize the pedal system.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12