zrx carb update 2.0 41mpg!

[yamahansolo]

I just filled up last night on the way to work and I figured my miles when I got there!!! Yippeeeee!!!

I figured it would be close to 40. The first 3 tanks had a touch of seafoam... I was getting about 35 to 37 with the foam... just did it cause the carbs were sitting for a couple of years in my garage. I still need to go up at least 1 pilot jet size hopefully the mileage will stay up...

[lee_dutcher]

damn sounds like a worthy upgrade.. how bought performance range can u tell the differnaces in the powerband? on the zrx carb are parts "CHEAPER"?

[yamahansolo]

If you read an earlier post I was raving about them!!! They are amazing. You can actually do a really hard rollon at low speeds in 5th gear! Throttle response is incredible. I need to bu pilots. I priced main jets at about 17 bucks for 4. Also I don't have any area of sluggish! The stock ones had a slight sputter at about 1/4 throttle while cruising. That is gone now. I didn't like the dual cable set up. I aquired one from a friend off a bandit 600. I ended up using just one of them with my stock sleeve. I wacked open and closed it very hard many times before I decided it would be great for riding with no problems. I need to take some pics and post them.
I read all the old threads about these carbs and everyone moved needle positions and or clipped the springs. I didn't do anything at all but make the mains bigger and opened the idle screws wayyyyyyy up 4.5 turns out. It also seems to engorge gas on start up. I use a clear fuel filter on my bike and it always stayed full. With these carbs the filter is almost empty. I may have to put 2 filters back on and then t them instead of t before. Or I may go with pingels?
I have noticed it was harder to start in the cold. Normally with my stock ones I didn't even need the prime I could just. Pull the choke and bam!
I found the zrx must use prime if its cold with the choke. This was the best 80 bucks I have spent thus far!!! I can't tell you how great they are. Did you see my video the other day

[lee_dutcher]

no but if it is on youtube ill find it...just wondering if i should just rejet the stockers or go with the zrx carbs but i guess if there cheaper part+ better performance i guess ill have to scrondge around the flea bay market... damn just when i thought i was done with the bike for he fall/winter everyone draws me back in...remindes me to buy a karosen heater

[yamahansolo]

The video is on this site search for my posts about the carbs. I rejetted the stock ones and it was pretty good but no where near this good

[yamahansolo]

http://www.xs11.com/forum/showthread.php?t=30398

[petejw]

hi yamahansolo,
what pilots are you running at the moment?
i had a look in my set, there 38 and ive got 40 for spares as well,
what main jet did you end up using?

im going to play with mine again soon.


this is how i set up my choke
its not pretty but it did the job.

[yamahansolo]

That looks like the choke cable I bought. I just need to put it on.
I think the pilots were 38's? Id have to check.

I drilled out the stock jets with a number 55. I used a set of pin gauges at work to measure them. They were 132 and 131. I am not sure what jet size that is. I can check the chart and see.

[yamahansolo]

Actually looks like maybe a 142 kehin according to my diamter chart.

[petejw]

thats just a cheap universal choke cable
available from any auto store,
i just stick a peg on it 2 hold it open.

uve got me keen to mess around with them again
i took em off cause i wanted the vac adv connected
correctly.

[yamahansolo]

I bought one from advanced looks identical. It came with a lot of different parts.

Also I have a small pilot jet from an 81 stuffed down the hole of the vac adv hose. I think its about .5mm.

Works pretty good. The 1st time tried them a while back I didn't hook the vac up with a restrictor and it bounced up and down a lot so I couldn't ride it that way.
If you read the post in the for sale stuff on the rs carbs the guy said he hooked his up with a .5mm restrictor if I remember right

[petejw]

if you connect the 4 nipples from the intake carbs
together using t pieces and hose, thatll stop the pulsating that occures when
you only connect to the one nipple.

i cleaned them up this arvo,
and ill probably try and put them on in the next cpl of days.
atm i put 40 pilots and have drilled the main jets with a 1.30
drill bit, i removed the washers that i had under the needles.
ill try it that way 1st and see how they run.



if you pull the carbies again can u measure the length of
the slide springs for me i think theyve been trimmed. tia.

[petejw]

nipple for vac adv onn zrx carbs

hi yamahansolo,
i hope you dont mind me posting this here
thought you might be interested,
heres a cpl of pics of an attempt to hook the vac adv
to the carbies instead of the intake boots.

i wouldve liked the hole to be a little bit closer to the butterfly but
more important it had to sit behind the butterfly and not in front of it.



ive used a bolt which i drilled the center so i could thread it into the carb body
like this, also i could have something to attach the vac hose to, ill use
an aquarium valve to help restrict the flow if its needed.



i also tried to put a groove into the butterfly like the one on the mikuni carb



havent tried the carbs yet,
its pouring rain down here atm, so no work for me tomorow
so ill stick em on and let you know how they go

[yamahansolo]

I don't mind. Also I may have confused you. Ihad the vac advance hooked to the number 1 carb. With the airjet in the hose the vac advance doest pulse. I had the side cover off when I first tried it without the jet. You could see it jump up and down. After I put it in it stopped. I didn't hook it to the manifold. So your saying to t it and hook them all together? I also thought about drilling out the carb like the stock one. I have the goods to try it but it seems to be good like it is. So I may hold off. I am curious as to how big your jets are now? I used a number 55 precision bit which should have got me 135 I think but it was only 132 I didn't want to order 2 sets of mains. I do need to get the pilots though

[petejw]

yeah if you link the 4 nipples on the carb boots with 't' pieces,
that will stop it pulsating but you would still need
to restrict it, the problem with this set up is that i found
the vac adv fully adv at idle, do u have that happening with it
connected to the carb nipple instead?

these are the metric drill bits i use



ive got mikuni jets 110 and 120
the drill bits 1.1 and 1.2 are an exact fit for these jets,

im using 1.3 drill bit on the main jets,
ill let you know how it all goes when i get em fitted.