zrx carb update 2.0 41mpg!

[yamahansolo]

http://static.photobucket.com/player...104_102705.mp4

[cywelchjr]

http://static.photobucket.com/player...104_102705.mp4

That's showing it fully advanced at idle and it retarding when you flick the throttle. This is NOT what the stock setup does. With the stock setup the vacuum advance is fully relaxed at idle, and when you bring engine speed up it will start to pull up, if from there you wack the throttle it will drop back like your video shows and then pull back up when the engine speed gets up to the throttle setting.

[xsroadrunner]

Fascinating mods you have there video is awesome too Bike sounds great and is real loud. And a beaut of a XS11 too. I have a bank of Suzuki GSXR750 slingshot carbs...wonder if they'll work as well as your ZRX carbs? How difficult a job was it to retrofit the carbs? Did you do a write up of it?

[oldnortonrider]

That's showing it fully advanced at idle and it retarding when you flick the throttle. This is NOT what the stock setup does. With the stock setup the vacuum advance is fully relaxed at idle, and when you bring engine speed up it will start to pull up, if from there you wack the throttle it will drop back like your video shows and then pull back up when the engine speed gets up to the throttle setting.

Yamahansolo~~what he said~~looks to me that it's full counter-clockwise, i.e. advanced at idle, and retards when you're giving it throttle. Wondering if you climb the rpm up slow, if it still wants to move clockwise/retard.............

(??)....may have to do the "T's" with hook-up to multiple intakes to your advance vacuum line to get a the low retard vacuum pull.......................

[cywelchjr]

Yamahansolo~~what he said~~looks to me that it's full counter-clockwise, i.e. advanced at idle, and retards when you're giving it throttle. Wondering if you climb the rpm up slow, if it still wants to move clockwise/retard.............

(??)....may have to do the "T's" with hook-up to multiple intakes to your advance vacuum line to get a the low retard vacuum pull.......................

Wouldn't work, it would still be manifold vacuum instead of ported which is what is needed. There should be very little if any vacuum at idle and then just off idle with no load should give max vacuum with vacuum level inversely proportional to load. Except for the no vacuum at idle part that's what he is getting, but the vacuum is not getting shut off at idle like it would with the stock carbs.

You gotta have that port that gets covered/uncovered with throttle movement. I think that Pete just has the hole a little big and/or just a hair too far forward.

[yamahansolo]

Ok maybe I got it backwards but when the bike is off the advancer is sitting in the exact same spot as when its at idle. When I pinched the hose closed all the way the way the vac advance doesn't move. Maybe I'll do anothher vid tomorrow showing this.
To make sure I am understandin you guys... when the bike is off the vac advance is resting at full throttle? This makes no sense to me. Not trying to argue just trying to understand. Also if this is the case then why is it when I have the choke on the adv. Pulsates until I pinch close the hose going to it.

[petejw]

i took a vid b4 i took off the mikunis off,

1st vid is of the vac guages
1st one is connected to the no2 carb barb,
2nd one is a restricted manifold
and the 3rd in unrestricted manifold (not relevant)



2nd vid is of the vac adv
if you look at the top pick up coil u can see it moving



yam, i couldnt get ur vid to work,

[petejw]

yam,
got your vid to work,
looks to me that ur full advance at idle,
try disconnecting it and take it out for a ride,
what pilots are you running atm?

[petejw]

hi xsroadrunner,
alanb from the uk site is running the slingshot
carbs on his bike from memory with really good
results, try doing a search not sure if he did a write up on,
but he has on the uk site.

welcome to the forum btw.

[petejw]

hey cy,
the only other thing i could try is soldering
the barb at the butterfly end and redrill with a tiny
drill bit, the solder wont stick to the alloy but will
to the brass barb, im waiting on sum 135 mains
so i wont b pulling the carbs until they arrive,
in the mean time i might try adv the initial timing
i was thinking around 5 degrees and see how that goes,

hey oldnortonrider,
ive tried that as well, connected the 4 barbs with 't'
pieces, this works well to prevent the pulsating effect,
but it still gives manifold vaccuum so it doesnt work either.

as i said in another thread,
im up for any ideas or theories, thanks guys for chiming in.

[yamahansolo]

Still running 38's. I ran it for a week with it disconnected already.

Your below the equator so yours goes in the opposite direction...

So at idle the stuff should be all the way to the right? And then it should go to the left when you open the throttle?

I am at work and my clymer is at home...

[petejw]

yam,
yeah sort off
it should be all the way to the right,
under throttle it should stay in the same
spot, only under decel or at steady state cruise
should the vac advance.
hope that make sense,
is the video i posted not to clear?

try running 40 pilots and see how u go,
i still reckon tho that if you connect to
the air box itll perform much better whether
the vac adv is connected or not.

if u jump on the uksite do a search for
irish kiwi, he has his set up nicely with an
air box and has a good video of how it runs.

[yamahansolo]

No way jose pods forever!!! They even have xs stamped on them... plus the sound comming out of them is unbeleivable.
I have been running it like this for about 2 weeks and I haven't noticed any detonation I'll see if I can get my other 79 to work and run them in the video together. Or I can just pop the old ones on for a bit. Also if its not running right why am I getting gobs of power and 40 mpg?

[petejw]

lol
ive been running pods for years
as well, i know where ur coming from,
i even get the ringing in the ears afterwards,

i just noticed in ur first vid after you reved it
it hung for a bit on decel around 1200rpm before
it dropped back to idle, but if ur happy with how its
running then thats the main thing.

[yamahansolo]

Well I am happy but I don't want to
blow something up...

The only real problem I had was trying to crank it but that was before I realized that the fuel filter was almost empty when I tried to crank. I have to prime it first every time. I never used prime with the stock carbs unless I let it sit for a week.

My other concern is when I pinch the hose closed it doesn't. Move the advance. It stays all the way to the left.
I'll check it again tomorrow... thanks for the input.