Cast Smartcarb?

portgrinder · Mar 4, 2014

Q500 said:
Ron just shipped my pulsed injection setup today. In the mean time I have been carving on a pwk on my work bench. With some careful machining you can run a 1/8" brass pipe through the float bowl. I have a feeling that I will experience zero carb icing with some big hp!

so you're essentially going to heat the fuel as it sits in the float bowl?

i think that will work but not sure how warm fuel may effect other things. i know the nice cold fuel spay into your crankcase is a real good thing.

dhdey · Mar 4, 2014

i am done with waiting for my smart carb, sent a few emails now and not got any response. sent one today asking for a refund..hopefully they dont f*ck me around, and once i got the cash gonna go for the pulse setup

summitboy · Mar 4, 2014

Not sure what your waiting for ? The billet is the only model I would use on the 500 in the snow. You could of got a billet half a year ago. I wouldn't heat the fuel.

dhdey · Mar 4, 2014

summitboy said:
Not sure what your waiting for ? The billet is the only model I would use on the 500 in the snow. You could of got a billet half a year ago. I wouldn't heat the fuel.

i didnt have $700 to spend then. been reading about way to many issues with the smart carb. i dont want to waste good riding days kicking all morning then hanging out in the truck while everyone rides. i really have a hard time believing the carb is all that with only a couple people raving about it

i was also told the cast was gonna be better and would work in the snow with the heating element. so far neither are true from the reports ive seen

Q500 · Mar 5, 2014

portgrinder said:
so you're essentially going to heat the fuel as it sits in the float bowl?

i think that will work but not sure how warm fuel may effect other things. i know the nice cold fuel spay into your crankcase is a real good thing.

Cold fuel is preferable from a performance stand point. A running bike makes even more sense. The actuall heat transfer into the fuel will be very low. Average temperature of the fuel will still be lower than a hot day in the desert.

portgrinder · Mar 5, 2014

hahaha ya true enough. really like to see how it works. would look a little more stylish than my coolant hose wrapped all around my carb thats for sure.

the gman · Mar 5, 2014

I went back and reread my post and want to clarifie something. I was not bashing the smart carb because of carb ice, just stating a fact. I have since installed my stock carb, with two heaters installed ( hot grip) , and the stock carb was no better at preventing ice than the smart carb. I did notice that the stock carb has a stronger return spring which seemed to help the slide not stick as easy, but still was a pain. I will also say tuning the stock carb was a pain....had to change main twice and needle once, to make it run anywhere close to as strong as the sc. I don't know why the smart carb works as good as it does, flat needle, vacuum in float bowl,??? Or maybe it's F.M......fricken magic but I have a billet coming now.

9Miler · Mar 7, 2014

WOW Gary you keep buying bikes the state is going to make you get a dealers license.

the gman · Mar 7, 2014

Somebody needs to keep the economy going:face-icon-small-ton

BUT IM ONLY ONE MAN

somepunk22 · Mar 14, 2014

Thanks to MTNdoo for selling me a cast smartie. I talked to the APT guys a little and designed up a cover over the slide cavity. Inside I have a 1" x 3" heater stuck to the side of the carb. Hopefully this should do the trick! I posted some pics and more details on my facebook. Its public so anyone should be able to view it.

https://www.facebook.com/dangodesign

mtn-doo · Mar 14, 2014

Awesome Dan! Your "magic" will be greatly appreciated. We all will work together and get the perfect heated Snow Bike Smart Carb. Confidence is high!!!

I am working on an aluminum tube design that works the same as the Rotax TM heated carbs on the sleds. That will allow non- electric bikes to heat as well.

dhdey · Mar 16, 2014

is the ice problem the slide sticking or the metering rod freezing up. i'm ussing a copper 'U' around the bowl of my keihen right now(and works great) and wondering if that would be enough to keep the cast smartcarb from freezing up. i also had it drilled for the ktm heater too.

eskimojoe77 · Mar 16, 2014

Heated float bowl?

I wouldn't think that heating the float bowl would have the desired benefit. There is cold fuel continually flowing though the float bowl taking any available heat with it. I'm planning to apply heat via coolant to the front or side of the carb body (slide area) to keep the slide from freezing and the carb throat from developing a layer of ice. The cold fuel is always going to be cold, the reservoir (fuel tank) is out in the cold and there is no way around that.

dhdey · Mar 16, 2014

eskimojoe77 said:
I wouldn't think that heating the float bowl would have the desired benefit. There is cold fuel continually flowing though the float bowl taking any available heat with it. I'm planning to apply heat via coolant to the front or side of the carb body (slide area) to keep the slide from freezing and the carb throat from developing a layer of ice. The cold fuel is always going to be cold, the reservoir (fuel tank) is out in the cold and there is no way around that.

it works great for my stock cr500 with kehin carb, used to have big icing issues now none.

thejean · Apr 21, 2014

My smartcarb arrived today finally. However I've made the move to a four stroke for next winter and not sure I need this carb for summer (bike works fine without it). To sell or not to sell...

mtn-doo · Apr 21, 2014

thejean said:
My smartcarb arrived today finally. However I've made the move to a four stroke for next winter and not sure I need this carb for summer (bike works fine without it). To sell or not to sell...

Heck, It's bought and paid for. I would put it on and take it for a test run. It will blow you away. Not even the same bike with the stock PWK. Also fuel mileage will go up approx 30%.

thejean · Apr 21, 2014

Yeah I suppose. And if I ever go back to a 2T...

dhdey · Apr 21, 2014

mtn-doo said:
Heck, It's bought and paid for. I would put it on and take it for a test run. It will blow you away. Not even the same bike with the stock PWK. Also fuel mileage will go up approx 30%.

i hate to be a basher. but the number of people with the smarty actually working well dont seem to be all that inspiring. i think their needs to be some serious issues adress. i really hope it does get sorted and i can pick one up for next season

mtn-doo · Apr 22, 2014

dhdey said:
i hate to be a basher. but the number of people with the smarty actually working well dont seem to be all that inspiring. i think their needs to be some serious issues adress. i really hope it does get sorted and i can pick one up for next season

No worries, you are not bashing at all. There are only a very small "few" smart carbs out there on snow bikes and they are the Cast models that cannot be heated sufficiently. I have a LOT of time on several bikes built with Smart Carbs. Their temp and altitude fuel delivery is more accurate and consistent than the basic moto version of efi. The weak spot is a good consistent heater. We have all owned and ridden two stroke snowmobiles. Sub-zero, deep pow, and run perfectly. It is not a high tech problem. We have decided to not "re invent the wheel" but design a trouble free system after the snowmobile carb designs.

It will be an easy fix, then the door will be wide open for zero tuning, spot on carbs for bikes. The demand is there, It will be done this summer. Already in the works.

summitboy · Apr 22, 2014

As MtnDoo said not too many on snowbikes as of yet. I just rode the CR all day and the CR ran flawless. Took a pile of kicks to get started cold. The big CR likes a ton of fuel and it takes a while for the case and cyl to get to the proper mixture. Once it was running it started first kick all day long. The bike stays jetted perfect. There was no carb ice to speak of that day. I believe once the heat is added to the carb the ice issues will disappear just like on the stock or PWK carbs.

The biggest fact that people seem to be forgetting is the carb compensates for alt and temp with no jetting change, more over rev than a stocker, and some more economy. No one ever said it would prevent ice although it runs very well with ice lol. Its a simple problem overall that will be short lived. Dont be afraid of a Smartcarb. They work very very well imo.

Cast Smartcarb?

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