APT smartcarb tuning advice needed

[upfront719]

So we just installed smart carbs on two 2014 ktm 300s this past weekend. Both bikes performed great in low range. 1st thru 3rd gear ripped! Mid to top end was sluggish (still was fast but just not as responsive as it should be). Before I installed the smartcarb I could wheelie in any gear.....

Any tuning suggestions??

Thanks!

 

[wwillf01]

There is a break in period for the carb... you need to run it hard for a few rides then it normally cleans up... I made the mistake of trying to adjust/jet right at the beginning then I had to change it after it broke in... I would talk to apt...
do you have dunes anywhere? That works well...

 

[upfront719]

Wallace - I spoke to Tom at APT and that was his initial thought as well (put more time on it). I don't understand what needs to be "broke in". Admitidly so, I don't completely understand the Smartcarb so that certainly doesn't help....

My problem is that I put the Timbersled kit on the bike since I have a few shows coming up, and I dont think I will ride it until we go out west in December. I really want to have this thing producing max HP while out in the mountains.

My buddy has the same bike as I do so we were going to try to dial his in, then make the same changes to my bike.

 

[wwillf01]

Wallace - I spoke to Tom at APT and that was his initial thought as well (put more time on it). I don't understand what needs to be "broke in". Admitidly so, I don't completely understand the Smartcarb so that certainly doesn't help....

My problem is that I put the Timbersled kit on the bike since I have a few shows coming up, and I dont think I will ride it until we go out west in December. I really want to have this thing producing max HP while out in the mountains.

My buddy has the same bike as I do so we were going to try to dial his in, then make the same changes to my bike.

So the rod itself is what is breaking in.... You can either remove the rod and run some leather over it.... But I would just wait to run it with the snow kit and that should do the job... You should only have to move the clicker a little bit for adjustment.... Also everything is stock on the bike correct? Did you make any other changes?


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[dirtrebel]

I ordered a spare heat collar for my stock carb, I will have it installed on the carb and at the ready in case the smarty does not work good. It was like 60 bucks, I figured I could try both.

 

[wwillf01]

I ordered a spare heat collar for my stock carb, I will have it installed on the carb and at the ready in case the smarty does not work good. It was like 60 bucks, I figured I could try both.

I can tell you this mine ran super rich for the first 200 miles or so.... Then it just magically cleaned itself up and I have never touched it again...... 100 degree swings and 8000 feet in elevation change over 400 hours on my 2013... Be patient...


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[upfront719]

No mods to the bike. Just added this smartcarb and I have to put the Avid Products heater on it.

 

[wwillf01]

No mods to the bike. Just added this smartcarb and I have to put the Avid Products heater on it.

Did you trim the airboot? I know on mine it got pretty jammed up not doing that..... It made the airflow much better? My first airboot cracked the second one I heated and formed it for the Smart Carb..

 

[mxracer299]

Mine took about 12hrs of hard riding to break in, its a process... I set mine up at 3,000ft and last week we were riding at 12,000ft and it was still running clean, there was an identical bike to mine with a stock carb and I got about 30-40 percent better mileage on a 90 mile ride, pretty impressive! That being said, I still have a small mid range bog that I can't get out of it, so I'm going to try a richer rod and see what happens. It does have a better low range and mid to top there is a little more power.

 

[mtn-doo]

Hey guys, I have been working with Michael from Cycle Playground on a new boot that accommodates the Smart Carb "plus" the Avid Carb Heater. It is a modified "XCW" boot. That boot is a straight line through without the big bend in the middle. It fits with the strut rod for our snow bikes. It is 1 3/16 shorter also. I may post pic's on a dedicated thread for easy access. Michael has 10 boots ready for orders.

 

[summitboy]

What are the settings you currently have ?

 

[adamd1979]

I can tell you this mine ran super rich for the first 200 miles or so.... Then it just magically cleaned itself up and I have never touched it again...... 100 degree swings and 8000 feet in elevation change over 400 hours on my 2013... Be patient...


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I've had the same thing happen with my new 38 billet. Way rich. I've got the 76 metering rod and have it at 100 clicks out. Still rich, but a bit better then the 78 clicks it was set at from factory. Is this similar to what you were finding before the 200 mile mark? If it doesn't lean out right, I may try the 80 rod that came with the carb.

 

[Jon Mutiger]

I'm surprised nobody around here is mentioning the Lectron Carb at all.. Locally to me nobody can seem to get a smart carb to work properly on dirt, yet the Lectrons work out of the box.

Has anyone here tried both to compare them?

Jon

 

[wwillf01]

I'm surprised nobody around here is mentioning the Lectron Carb at all.. Locally to me nobody can seem to get a smart carb to work properly on dirt, yet the Lectrons work out of the box.

Has anyone here tried both to compare them?

Jon

I have both..... My Lectron did not work out of the box it had the same type of break in period... Mine ran crazy rich until it was broke in.... I had to turn the rod almost a turn and a half because it was so rich then once it broke in I turned it back to stock... But the Lectron is a great option but most people I have talked to seem to think the Smart Carb is more refined.. I really like not having to take it apart to adjust the rod...


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[portgrinder]

whoa whoa whoa, stop the clock!

carbs that break themselves in?

pls explain.

 

[wwillf01]

The way it was explained to me is the rod that is used has to have fuel flowed over it for x amount of time to set right..... I am not a mechanic I only know what happens from the 2 I have ran...


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[Comp 670]

whoa whoa whoa, stop the clock!

carbs that break themselves in?

pls explain.

Yes, please explain WHAT part in the carb CHANGES as you use it? How does it "know" when to quit "breaking in" to achieve the best AF ratio?

I'm not saying they don't work, just trying to learn how they do work!

 

[wwillf01]

Yes, please explain WHAT part in the carb CHANGES as you use it? How does it "know" when to quit "breaking in" to achieve the best AF ratio?

I'm not saying they don't work, just trying to learn how they do work!

The metering rod needs to vibrate within the nozzle to produce the high atomization. Without this vibration the bike will run lean. The rod and nozzle are a tight fit when new and require some break in to allow for this in some circumstances.




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[Comp 670]

Ok, so does it keep wearing and eventually go rich?

Sounds like the carb builder needs to invest in a wet flow bench so they can flow them and "break in" the carbs before shipping them out.

 

[wwillf01]

I agree something needs to be done... But that does not negate the fact that it is more than likely the issue... I have ran my lectron for 400 hours and 3 top ends and have never had to touch it again... The smartcarb is still new...


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