APT SmartCarb
- Thread starter gasgasman
- Start date
It's tank foam, just like you find in racing fuel cells. It's there to provide additional baffling to give the fuel pickup a tranquil area to pull fuel from. If your not doing sick whips over log jams like Wally Palmer you probably don't need it. It will last for years but can be removed easily enough if you like. Corey
siaknijustin
New member
I put mine on my 300 after swapping to the shorter rod, checking slide height, checking float height and sanding the crap out of the throttle cable end. The bike started on the 3rd kick w/ choke. It hadn't been run since mid February.
Once up to temp w/ choke off, I could tell that the suggested setting was a little lean. Unfortunately, I'm waiting on rear wheel bearings and so I didn't bother with richening up the settings.
As far as float height and slide height were concerned, they were spot on as delivered (checked w/ calipers and a feeler gauge).
Sanding down the end of the throttle cable was a total PITA! I had to have spent 30 minutes on it before it would fit into the groove on the slide.
siaknijustin
New member
The shorter rod # is RO76 (There was a laser etched E12 on mine that I've no idea what the meaning is). The setting Corey provided me was 55 clicks from full rich. The longer rod is an R078 and mine came at 59 clicks from full rich. I never ran it with the longer rod because of the many reports of a lean top end.
I'm going to check the plug gap before any further adjustments because there was one report on the orange site stating that excessive plug gap had caused a lean symptom. Speaking of that, what is the factory recommended spark plug gap? I generally run about 0.034".
siaknijustin
New member
I've only got about 5 hours run time on mine but I suppose that I can post an "initial impression." So far mine has been very consistent throughout all throttle openings. The only inconsistency that I've noted at this point has been the idle and the only time it's inconsistent is before the bike is up to operating temps. At that point the idle becomes more consistent that I could ever dream of my Keihin being. So far mine has seen 4k ft elevation and +or- 30f temperature changes and has run the same at all times. 
This is precisely why I bought the carb; I see huge temperature and elevation swings.
For the bad (take this w/ a grain of salt): I am experiencing some of the off-idle blubber that others have noted. I am still trying to tune this out as my plug readings are still rich. Once I got the spark plug gap right and up to temp I could tell that I was terribly rich (not lean as noted above). I'm a lot closer than where I started but still not quite there. Every other throttle opening is great and top-end over-rev is better than the Keihin.
Also, on the old style subframes up to 06, the carb has to be angled all cockeyed to not make contact w/ the cases. Corey is working on a drainless float bowl for me and I believe that will relieve the clearance issue.
Overall I'm happy w/ the carb and for someone w/ varying conditions I'd strongly recommend it.
*please note that off Idle blubber isn't an inconsistency; it's always there. However, I'm confident that I can tune most (if not all) of this out.
I'll post more as I go but realize that I don't get out near often enough.
This is precisely why I bought the carb; I see huge temperature and elevation swings.
For the bad (take this w/ a grain of salt): I am experiencing some of the off-idle blubber that others have noted. I am still trying to tune this out as my plug readings are still rich. Once I got the spark plug gap right and up to temp I could tell that I was terribly rich (not lean as noted above). I'm a lot closer than where I started but still not quite there. Every other throttle opening is great and top-end over-rev is better than the Keihin.
Also, on the old style subframes up to 06, the carb has to be angled all cockeyed to not make contact w/ the cases. Corey is working on a drainless float bowl for me and I believe that will relieve the clearance issue.
Overall I'm happy w/ the carb and for someone w/ varying conditions I'd strongly recommend it.
*please note that off Idle blubber isn't an inconsistency; it's always there. However, I'm confident that I can tune most (if not all) of this out.
I'll post more as I go but realize that I don't get out near often enough.
CACTUSREID
New member
well after 1331 reply's to the smart carb question, i know what my answer will be-why bother? when i first started reading this thread, the smart carb was the answer to all the "issues" people were having about jetting the gasser's. it's really not that hard to get a gasser to run well with a khein carb. just my 2 cents worth. i'll be out riding,not jetting with a keyboard if anyone wants to contact me. enjoy the new simple smart carb.
john, for some reason my account expired and I can't read your PM's. I've re-registered, so feel free to correspond through PM's here if you like. After the convoluted nightmare and continual delays of the cast pre purchase program a typo put you down as cancelled and your carb was not shipped. Apologize, I personally test and had one shipped to you yesterday.
It's easy to be critical of something you have never even seen or experienced.
It's no secret manufacturing issues put a damper on the first run of cast SC's and that slowed things down a bit. What is not understood by most in the dirtbike community is that we are certifying carbs right now for on road use in the US without the need of precious metal catalysts. Unprecedented. The SC is also the only mechanical fuel system that can atomize Diesel and military spec JP fuels and we have several pending contracts for military outboard applications. It would be altogether to easy to just step away from off road dirtbikes and it would probably not even affect our bottom line. This is a passion play folks and we approached the dirt bike community first because we knew this is a product that is very much needed in this world. I've ordered 500 more each of the Cast 36, 38 and 40mms. So just keep tuning on that Keihin, before long the SC equipped bikes will be mopping the floor with anything less. 2 and 4 strokes.
Just installed my cast version last night... Hopefully you'll stick around and be active here so I can reach out to ya in the event I have questions!
Just installed my cast version last night... Hopefully you'll stick around and be active here so I can reach out to ya in the event I have questions!
Yep, have my account up and running again.
You have the cast 36's coming soon?? I've been patiently waiting for them......
Thank you for responding to this thread and updating us a bit.
JP4
New member
Like others, I've been following this thread and waiting for good news on consistent delivery and positive endoresments of the cast SC before ordering.
To date, I've not seen that ... maybe I'm missing something?
If delivering SCs to the off-road M/C community is neither your core focus, nor key to your business model at this point in time, then maybe you shouldn't bother? If you think you're doing us a favour by letting us send you money for a product that has a pretty sketchy delivery schedule, and some reported issues, wow!
It may be the bomb, but unless you can deliver it as promised, I'll never know.
Given the history, I'll wait patiently and let others jump first ...
Just saying.
