New Carb in Town

[Ausm7499]

If this carb is as good as they say I see no need for fuel injection, and my carbed bikes might be getting an upgrade.

It's called the APT SmartCarb and I guess it self compensates for changes in air density so your jetting is always spot on. Here is the thread on KTMtalk

http://ktmtalk.com/index.php?showtopic=463188

Their website

http://www.powerapt.com/smartcarb.php

I read through the whole thread and it sounds legit, I guess they only have billet carbs available right now which are like $750 but they are coming out with a cast model this spring with a price of $350-$400 which wouldn't be bad.

I am thinking one of these would be the ticket on my CR500-MH

 

[wwillf01]

Here is a review it looks pretty interesting!

http://www.gasgasrider.org/forum/showthread.php?t=13471

 

[wwillf01]

Do you think without a heater they will freeze up on a 2 stroke

 

[CATSLEDMAN1]

organized leak

I like the concept............works on a 4 stroke ?

in the day I bought the old Lectron carbs. when all Mikuni and Keihin had were round slides carbs, the flat slide lectron was a HUGE improvment in throttle response and low end pull. Eventually both Mik/keihin made flat slides that worked and you don't hear much about the lectron/bluemax/megatron. They did work well.

If the new carb company would machine the body out of plastic, then maybe we would not have to sweat icing, aluminum body, will likely still ice in bad conditions.

 

[powdermuncher]

The Icing issue is not from the outside --- it is what a carb venturi does on the inside that generates Icing.

 

[Ausm7499]

I think icing would still be a problem that would need to be resolved.

Looking at their website I think they have or are in the process of building 4stroke carbs.

 

[coreyd396]

I think icing would still be a problem that would need to be resolved.

Looking at their website I think they have or are in the process of building 4stroke carbs.

Most of the early development was done in Wyoming on snowmobiles, icing has never been an issue.

 

[Ausm7499]

Most of the early development was done in Wyoming on snowmobiles, icing has never been an issue.

I wouldn't suspect icing to be a problem on a sled, they have a hood to hold in the heat from the exhaust and keep the snow off the carbs, much different environment then a carb on a snobike.

 

[coreyd396]

I wouldn't suspect icing to be a problem on a sled, they have a hood to hold in the heat from the exhaust and keep the snow off the carbs, much different environment then a carb on a snobike.

Agreed. Also wondered about radiators on the mountainhorse conversions and how even running temps are. Also noticed not many two stroke snobikes, probably due to the same conditions.

 

[CATSLEDMAN1]

icing on the carb

couple of thoughts.....

the icing gets bad when the venturi super cools the somewhat wet icoming air mixture and makes the carb body way colder than outside incoming wet air and then wet air begins to freeze to the inside of the overcooled carb body. Would that happen with plastic carb body ? I'm betting not. Some one please stand up and cnc a plastic replica of a Keihin carb, I've got tooo much on my plate right now, I want to know.

 

[Jon Mutiger]

Carb icing happens more on smaller body carbs. Bigger carbs have less speeding up of the air, thus less cooling and dropping of the moisture in the air as it speeds by. I've had a bike which used to ice on a rainy day in the dirt, I swapped out the carb for a larger one and it was gone.

Jon

 

[Wyorever]

Wow, just scrolling through SW and low and behold look at what I find!

I used to work for APT while they were still in WY. I dynoed a few bikes and helped dial them in for them while still there, and I currently run a set of 40mm prototype billet aluminum flat slide APT carbs on my REV. Unfortunately, when they decided to move the R&D to Missouri I no longer had a job.

Yes, they do work, they are what they are cracked up to be. I helped set up a Gas Gas 300 for 7200 ft, the owner came and picked it up, drove to a race in TX, made two small adjustments, that took maybe 30 seconds, and said the jetting was spot on.

As far as icing is concerned, I don't see it being an issue. A guy I consider to be like a father runs an APT SC on a 300 XC regularly in cold, damp, wet conditions without an issue. No, it's not 10 deg weather, but its pretty cold.

My REV runs like a top with the carbs.

 

[Ausm7499]

Wow, just scrolling through SW and low and behold look at what I find!

I used to work for APT while they were still in WY. I dynoed a few bikes and helped dial them in for them while still there, and I currently run a set of 40mm prototype billet aluminum flat slide APT carbs on my REV. Unfortunately, when they decided to move the R&D to Missouri I no longer had a job.

Yes, they do work, they are what they are cracked up to be. I helped set up a Gas Gas 300 for 7200 ft, the owner came and picked it up, drove to a race in TX, made two small adjustments, that took maybe 30 seconds, and said the jetting was spot on.

As far as icing is concerned, I don't see it being an issue. A guy I consider to be like a father runs an APT SC on a 300 XC regularly in cold, damp, wet conditions without an issue. No, it's not 10 deg weather, but its pretty cold.

My REV runs like a top with the carbs.

Glad to hear from somebody with first hand experience, with that said I am going to disagree with the icing. It's still a carb without any heat source, it still has a slide, and it still pulls the same amount of air through a small aluminum carb body.

 

[Wyorever]

Glad to hear from somebody with first hand experience, with that said I am going to disagree with the icing. It's still a carb without any heat source, it still has a slide, and it still pulls the same amount of air through a small aluminum carb body.

Fair enough, everyone's entitled to their own opinion. I guess it comes down to who's going to be the guinea pig?

 

[powdermuncher]

If it has a Venturi it will make ice. Fuel injection does not use a Venturi so it does not ice . It is that simple .
Even different carbs make ice at different rates depending on the shape of the Venturi. That is the bad not so new news.
The good news is that it does not take much heat on the carb body to keep the ice from sticking to it.

 

[mtn-doo]

Hey guys,
Here's a sneak peak of the next performance mod we have all been looking for. No more jetting, period! Highly atomized fuel over the more liquid state our simple EFI's and Carb's deliver, and altitude compensating advantages that our simple EFI systems cannot deliver. We are very excited to put this to the test. It could be the "no hassle" answer for all of our carbed "and" efi bikes, with simple efi systems. It also applies equally to 4-strokes and 2-strokes. Here's a link to the company site. The technical advantages are impressive. They equipped a Pikes Peak race bike, "4-stroke", and it ran consistent AFR's and EGT's from a sea level base setting, to the top of Pikes Peak at 14 thousand feet! No jetting required. wow!
Now it's going to be put to the test in the mountains and snow.
Check this out.

http://www.powerapt.com/smartcarb.php

 

[J&L Snowhawk]

when

when are u testing this on the kx500. my kx is getting brought back to life and this would be worth the money to eliminate the jetting headaches.

 

[mtn-doo]

when are u testing this on the kx500. my kx is getting brought back to life and this would be worth the money to eliminate the jetting headaches.

We are getting familiar with it now, and will be putting through a lot of altitude and load condition testing right away.

 

[Wyorever]

We are getting familiar with it now, and will be putting through a lot of altitude and load condition testing right away.

Glad to see one of you guys got your hands on these! I'm sure you will be pleased with the results! Nice work on the Service 500 and I'll be looking for more videos, hopefully in this thread.