Ordered smartcarbs

[lost1750GTV]

Yes, I know some will consider these pricey carbs as the definition of insanity, but redoing my floats, playing whack -a - mole with the upper lower cascading fuel design, trying to get a float height specified as too low that works, while trying to sort jetting AND dealing with old carbs that would be leak free one day, and start leaking next time I turned the gas on - all that was for me the definition of insanity. I will pull no more carbs forever, to paraphrase.
The float height doesn't have to be reduced for lean angle, the method for setting seems idiot proof (how much fuel is in the float bowl when you remove it), and you set mixture with an external knob. So maybe I'll spend more time riding next season than breathing gas fumes.
If outside comparisons (36 vs other 38s) are accurate, the 28's should flow as well as other 30s at max, but the pear shaped venturi allows it to respond like a smaller
at smaller openings.
And according to multiple dirt bike tests, if I get it jetted pretty right on a decent winter day at near sea level, it will be good for a run to the new hampshire mountains on a hot summer one.
Luckily as I was getting ready to bite this bullet and spend $ I had planned for cf wheels (dymag still shut down) they announced a weeklong discount on Thanksgiving.
Not quite plug and play, as I'll need a set of throttle cables from Bill Wilson, his mikui/keihin 5 cable set up will be compatible, but will likely scrap the double k&n set up he sold me for individual units.

[hailwood1965]

I've never heard of them. What makes them better?

[David_411]

You'll love em.

I've experienced them on dirtbikes and they are truly revolutionary when it comes to carbs.
Incredibly simple and reliable. They do not leak or stick.

I always laugh when folks say carbs are more reliable than fuel injection.
Over my years in the dirt realm I've had floats stick, jets plug.
Smart Carbs are the closest thing I've seen to EFI.

[lost1750GTV]

Glad to hear that, David. I stumbled onto them through dirt bike reviews so did a lot of reading on them. For the most part those guys are trying to solve different issues than me, number of miles to a tank, elevation changes, or abrupt low end power.
My big issue (short answer to hailwood), what they are is a time saver. Anything else is a fringe benefit. A shop called Italianiron(?) Thinks they are great too, run them on a variety of Ducati.
Slightly longer answer, a much revised lectron with a lot of good ideas.
Longest answer www.smartcarbfuelsystems.com

[Ade SYM]

What sizes have you ordered?
Do you know the specifications of the build as I have just enquired about these and have notice I can save a load of £ if I order direct and not through a middle man
Thanks
Ade

[lost1750GTV]

Hi Ade - I ordered 28's. They haven't advised on the rod grind, but it does vary depending on rpm, expected power etc.
If you are doing something special it could need a different rod than I end up with.
The 26 & 28 are small body and fit the standard intake boots. Next size up is 36/38/40 and I expect that body would need a different intake.

[TwoStrokeNut]

I wish you luck. Carb problems are frustrating and I hope yours are a thing of the past. Let us know how they work out.

[busa1300]

Hope you have better luck with those than I did with the Lectrons I got for my RGV last year....
I finally gave up and have a stock set of carbs to go back on...

[lost1750GTV]

Don't know what your lectron issues were - but it seems to me that starting by being able to set the float at the proper height helps a lot with tuning. The rod height can be altered without removing anything, and the rod can be changed from the top with the carb on, so even if I have to go through multiple attempts to get it right, each attempt will be less time consuming and won't involve fuel spillage. Of course the hope is that these guys look at the rpm//hp/dyno charts I've pulled from here, and are able to ship it pretty right. Its not much different from mini mx85 and super mini 112 mx so they have knowledge to compare with.
If I'm wrong about all that, well, I have done stupider things, and the resale market for them is pretty strong..
If it all works, it would be a lot easier to to an in the V set up at rebuild time, given the above.

[busa1300]

Rods for the Lectrons were $30 each...I have tried 3 sets and still no luck.
Maybe the new carbs have it figured out better with needle design.

I will watch, as I am tired of pulling my stock RZV carbs off endlessly for issues

[lost1750GTV]

"Tired of pulling"
Thats it for me too .

[David_411]

The smartcarbs have an external clicker for fueling adjustments. Technology Elevated is usually very good at dialing in the rod on the first go.

From there it is just simple clicker adjustments to dial in the fueling mixture.

They're also completely sealed. You only have one drain tube coming from the float bowl. No mess of tubes dangling off the carb body.

These RZ carbs drive me bananas. You think you have it set and it's not. Either it's idling smooth with a good response, but then dies mid to upper RPMs. I can never get it all.

[Luther]

Rick Lance worked on so many stock carbs that he could clean a set up and know exactly what if anything was wrong after a short ride. I think I got excited when after a few years I finally stumbled on a couple small adjustments and WOW its like a whole whole different bike, fast smooth crisp and clean. So I did what most 2 stroke nuts do and got some TM 28's to spend 10 years adjusting to see if I could get a little more.

GTV, good on you for trying these out for all our benefit. 28's are the right size as the ballance pipe lets them flow like bigger carbs at large throttle opening.
I want to hear how they fit the stock rubber spigots and if they bump each other. Are the fuel nipples in a good spot? Your going to use pod filters? I have a machine shop if you need help with fitting them up

[lost1750GTV]

"I have a machine shop" careful with offers like that,Luther!
There is a good thread titled "tsi porting" from 2006, where rztom has informative 3 dyno runs - but basically, yeah, stock works as long as you are stock, from air cleaner to pipe. And I'd say, from my spotty testing, that at up to 3/4 throttle, even with Bill's k&n set up and jolly, the stock works - but get the rpm up and things seem to fall apart. I blame it less on the 26's and more on the reduced float height, my conclusion that not enough fuel is delivered (hence lean regardless of jet size).
Years ago Bill did a mock fitting on intake boots/stripped cases which look like no issues - but no picture of the bottom left, where there are bosses on the outer case which might be an issue - Bill says no, i hope he's right.
Fuel lines don't look like they will be an issue at all, but the choke knobs may need to be lengthened or a lever attached for access. With the big oval filters on now I dont think it will be a problem, and individual pods should be less of a concern, but we shall see. Pods should go on easy, but if I wanted to keep the wilson set up then the backing plate would need to be revised and boots fashioned, maybe from big intake manifolds mounted backwards.
Of course I'm hoping that the 28's flow like 30's at wide open, due to the pear shaped venturi. Kinda like having a powervalve on both ends haha
But with no basis for comparison other than intermitttently ok stock carbs with the k&n and jollies, my best hope/expectation is that I will be able to say easy mod, easy tuning, no leaks, and seat of pants noticeably faster than my few good test runs on the old ones.

[rz500guytexas]

Rick modified many sets of carbs. If you are lucky enough to have a set you better never sell them. You can see if they are modified by the two air jets installed. People always thought it was easy to just put bigger carbs and breathers on. Only to find they never performed well though the entire rev range. There would always be a surging or bucking around 3,500 rpm at steady throttle. I was fortunate to speak with him at length about the issue. In my simple mind it was once the elephant ears were removed you were done. The stock carbs were designed with a restricted intake in order to draw fuel in properly due to the high negative pressure entering the carb at all throttle positions. I run his tripod filter set up and with a proper sync they run flawless. If you are going to modify with larger carbs for the track I guess it makes no difference. The RZ was based off the race bike and the 90 degree fitting to the engine are the weak point from my understanding. Be interesting to see how the smart carbs work both in performance and rideability. You see very few videos of people actually cruising on their bikes. They are either wide open throttle on the street are just being revved up in a garage. Here are some videos of setting my track bike up originally. The bike pulled without a stutter.

1/4 throttle
https://www.youtube.com/watch?v=aCy2USNp9Es
1/2 throttle
https://www.youtube.com/watch?v=wZR52zlRv3E
3/4 throttle
https://www.youtube.com/watch?v=KfGiZwefjnY
wide open
https://www.youtube.com/watch?v=S9U2JR5yltc