APT Smart carb for Keihin FCR

[adamd1979]

Talked to Steve from APT about a smart carb for my KTM 540. He said they are planning on completing a billet version by early fall. For those of you who have tried using an APT carb or know more about it, what would the advantages be by dropping one in a four stroke? Would this even help with carb icing, or just help with temperature changes and altitude?

 

[summitboy]

The Smartcarb billet and cast 2 stroke versions have a great deal of advantages over a stock equivalent ! I believe they did a lot of testing/development on the KTM 300 bikes.

They compensate for temp and altitude. No jetting is required, rather a few clicks of the metering rod for off idle circuit. You see more bottom end say on a 36mm carb with a snappier throttle response throughout the range. With a 38mm you get more bottom end and a nice top end over rev as compared to the stock 36mm KTM carb.

Also they say 10-20% better fuel economy.

On the 300 it makes the power valve more sensitive and allows it to be tuned more for the condition. There are no vent lines hanging off the carb which makes them more EPA friendly since in the very near future that will be a requirement because they don't leak fuel all over when on the side etc.

Mtn Doo here on SW has a billet version on his KX500 and has said one big plus he found was when the air filter iced up or having ice in the venturi made no difference to the way the bike ran. Jetting is spot on unlike even the fuel injected bikes in this condition. You can get them to make your carb accept the KTM carb heat as well.

I have a cast 38mm on order for my CR500 project bike. I should see it by May 1. Once tuned on my Cr500 it is going on my KTM 300 for the summer. Can't wait to try it out ! There is a ton of positive feedback on the Internet thus far ! Corey from APT is an excellent resource and a passionate individual for this awesome carb !

Ps. I want the dealership for western Canada LOL

 

[thejean]

Hmmm, methinks I'll be looking into these for my 300...

 

[Ausm7499]

I will be buying a 38 cast to swap between my CR500 and KTM300. I have read the entire thread on KTMtalk and the reviews look good so far.

 

[mtn-doo]

Talked to Steve from APT about a smart carb for my KTM 540. He said they are planning on completing a billet version by early fall. For those of you who have tried using an APT carb or know more about it, what would the advantages be by dropping one in a four stroke? Would this even help with carb icing, or just help with temperature changes and altitude?

I visited with Corey from APT today about the 4 stroke APT application. Give them a call. They have been running them on 4 strokes in world class competition and winning. The APT on a 4 stroke is current and hugely successful. We have been zeroed in on the 2 stroke application and have not dug very deep concerning the 4 stroke with the APT. We discussed that a bit today and they can set you up for your 4 stroke. I would definitely give them a call.

 

[M5-]

Ps. I want the dealership for western Canada LOL

Can you say good deal? LOL

M5

 

[adamd1979]

I visited with Corey from APT today about the 4 stroke APT application. Give them a call. They have been running them on 4 strokes in world class competition and winning. The APT on a 4 stroke is current and hugely successful. We have been zeroed in on the 2 stroke application and have not dug very deep concerning the 4 stroke with the APT. We discussed that a bit today and they can set you up for your 4 stroke. I would definitely give them a call.

That would be great. When I talked to Steve it sounded like they did not yet have a production unit ready for my fcr carb. He said that he had a carb they made for his bored out honda 530 4wheeler that was a 46mm(wow) and it ran like a wild thing, but not that it was being sold to the public. For me, the appeal to this carb is that it has the ability to adjust on the fly. I hate dealing with jetting and I'd be willing to give it a try. For all of us oneskiers, is there any interest in a carb that solves jetting, dumping fuel when upside-down, and possibly icing?

 

[Lachoneus]

YES

and the appeal to me is not running a fuel controller, risking dumping fuel in oil and engine damage, etc. Curious to see how it pencils out putting a SmartCarb on a 4-stroke bike. What costs/work would be involved over and above the cost of the SmartCarb itself?

 

[mtn-doo]

and the appeal to me is not running a fuel controller, risking dumping fuel in oil and engine damage, etc. Curious to see how it pencils out putting a SmartCarb on a 4-stroke bike. What costs/work would be involved over and above the cost of the SmartCarb itself?

I don't believe there will be any other factors other than just the carb itself. The ignition map would run stock, the throttle body and injector will simply be removed? I think it will be a very simple swap? We will find out. When I visit with Corey again, I will try and get specifics.