APT SmartCarb

[Jakobi]

Good luck at Romaniacs Michael

Thanks for the reply Corey. I too am interested in the specs on the rod. Is it possible to spec it up myself in the meantime while I wait for the replacement? It can sometimes take up to a month for parts to ship from the states to aus depending on postal method. I also understand the logic behind not having an air correction circuit, but it really does rely on the metering rod being spot on.

In regards to Mikes TMs, can you elaborate on the issues he was experiencing and how they were resolved?

 

[Suns_PSD]

Sadly, I need to ask for VERY specific directions on how to set the float height on the Smartcarb. I don't get it. Anyone?

Also, Corey, what are the plans for the Grose valve and will it be something I can add later? My intention is to turn my bike in to a DP eventually and it would seem that the Grose valve would really help in that situation.

PS. Also, why don't you guys offer a 1/4 turn float bowl drain that can be accessed by hand. I'd pay extra for that. W/ a drain line running underneath the bike would even make it better.

 

[drehwurm]

There is a bit about setting the float level in the manual so once you get yours it should be pretty clear.

What I do is remove the carb from the bike and then remove the float bowl keeping the carb level all the time not to spill fuel. Measure the fuel height in the bowl to get a base setting. Adjust the tab on the float arm in the direction you want to go (lean, rich). Drain the bowl and mount it back to the carb with only two screws. Now comes the tricky part. Connect the fuel line to the carb (still off the bike, no slide), open the choke and slowly start opening the fuel tap. If you did it right no fuel will gush out of the metering tube and you can go back to step one and measure again.

Michael

 

[flybars]

Sounds like a pain. I was hoping to just install the SC and ride.

 

[drehwurm]

Sounds like a pain. I was hoping to just install the SC and ride.

I've read reports where people just did that! Unfortunately there is another group which was not as lucky - be it either defective rods, just being very picky or the "hardware" playing a bigger role than anticipated. IMO the perfect setup will be a SC delivered stock on a bike with parts like the airboot correctly designed to fit and pipe, PV, ... setup accordingly - 2-stroke Nirvana

Michael

 

[Corey]

Sadly, I need to ask for VERY specific directions on how to set the float height on the Smartcarb. I don't get it. Anyone?

Also, Corey, what are the plans for the Grose valve and will it be something I can add later? My intention is to turn my bike in to a DP eventually and it would seem that the Grose valve would really help in that situation.

PS. Also, why don't you guys offer a 1/4 turn float bowl drain that can be accessed by hand. I'd pay extra for that. W/ a drain line running underneath the bike would even make it better.

There are two ways to measure the float height. One is to measure with calipers from the float bowl gasket surface on the carburetor to the tips of the float arms. Usually .102" puts it really close. The one I recommend, simply because there is some inconsistency in the Mikuni needle seats we have chosen to use. Is to fill the float bowl, then while holding the carb vertically remove the bowl screws, pull the bowl off and measure the standing fuel height in the bowl. .775" or roughly 20mm from the bowl gasket surface to the top of the fuel.

The grose jet inlet valve will likely be standard on all SC's before long. Our number one issue is the $^&@! sourced floats that we have been using and it has to get much better than this.

We have drains on the bowl now, and about a quarter turn is all it takes to open it. Now just need a big thumbwheel on the screw. The hose fitting on the bowl will allow a hose to be placed under the engine.

 

[Corey]

Good luck at Romaniacs Michael

Thanks for the reply Corey. I too am interested in the specs on the rod. Is it possible to spec it up myself in the meantime while I wait for the replacement? It can sometimes take up to a month for parts to ship from the states to aus depending on postal method. I also understand the logic behind not having an air correction circuit, but it really does rely on the metering rod being spot on.

In regards to Mikes TMs, can you elaborate on the issues he was experiencing and how they were resolved?

Jakobi,

I see the KTMtalk forum is back up. MikeS has posted most of the issues they have had over there. Also have shared quite a bit of information on their cycleplayground website. I would check those.

 

[Diggs345]

There are two ways to measure the float height. One is to measure with calipers from the float bowl gasket surface on the carburetor to the tips of the float arms. Usually .900" puts it really close. The one I recommend, simply because there is some inconsistency in the Mikuni needle seats we have chosen to use. Is to fill the float bowl, then while holding the carb vertically remove the bowl screws, pull the bowl off and measure the standing fuel height in the bowl. .775" or roughly 20mm from the bowl gasket surface to the top of the fuel.

The grose jet inlet valve will likely be standard on all SC's before long. Our number one issue is the $^&@! sourced floats that we have been using and it has to get much better than this.

We have drains on the bowl now, and about a quarter turn is all it takes to open it. Now just need a big thumbwheel on the screw. The hose fitting on the bowl will allow a hose to be placed under the engine.

Thats the way i check my float level , is that 20mm on the new float bowl corey ? , i cant get anywhere near that with the bike in the meat of the powerband without the bike sucking the cab dry .

 

[Jakobi]

Jakobi,

I see the KTMtalk forum is back up. MikeS has posted most of the issues they have had over there. Also have shared quite a bit of information on their cycleplayground website. I would check those.

Thanks,

I had a check and a read on the CP site. I also read the whole other thread previously and may have missed it, but didn't see anything technical that actually outlined his issue and how he resolved it. I also only just realised his model is using the grose valve, where I'm on a needle and seat setup.

For now I'm just waiting out the time until a replacement MR arrives and hoping that will be the fix. I'm feeling positive.

 

[drehwurm]

Our number one issue is the $^&@! sourced floats that we have been using and it has to get much better than this.

I agree! The floats were the last thing I hadn't played with so far since the float level seemed always fine around 19-20mm. Just to have it touched I bent the tab on the float arm 0.25mm down (towards lean) and it significantly changed the SC behavior. I had to go 15 (!!!) clicks richer to get rid of a suddenly severe hanging idle, my idle in general is much more consistent now and actually this is the 1st time I'm fairly happy with the SC in all areas. Bending the tab was the only change I did and the effect on the float level itself was minimal - less than 1mm change in float height. Slowly I'm starting to think that my original SC was changed out in transit and somebody replaced it with a cheap Chinese copy

Michael

 

[modette]

Sounds like a pain. I was hoping to just install the SC and ride.

I did that

 

[GMP]

So did Girard, set and forget. Thats how this whole thing got started.

 

[Corey]

I agree! The floats were the last thing I hadn't played with so far since the float level seemed always fine around 19-20mm. Just to have it touched I bent the tab on the float arm 0.25mm down (towards lean) and it significantly changed the SC behavior. I had to go 15 (!!!) clicks richer to get rid of a suddenly severe hanging idle, my idle in general is much more consistent now and actually this is the 1st time I'm fairly happy with the SC in all areas. Bending the tab was the only change I did and the effect on the float level itself was minimal - less than 1mm change in float height. Slowly I'm starting to think that my original SC was changed out in transit and somebody replaced it with a cheap Chinese copy

Michael

If resetting the float tang made that much difference then your floats have had a small leak all along. Maybe not replaced with a cheap copy during shipping, but certainly kicked along on its way. Shipping the carburetors are hard on the dangling floats. We've considered packing the bowl to hold the floats tight, but wasn't keen on making people immediately take the bowl off when they received it. But may have to consider something to remedy the problem. I normally suggest a float check when someone is having issues like you described and thought we had discussed. Anyway glad to see you are starting to get good results like the others. Corey

 

[Corey]

In regards to Mikes TMs, can you elaborate on the issues he was experiencing and how they were resolved?

I had just installed a Grose jet inlet in my personal 38mm for my GG 300 for testing. I met MikeS and Michael at the trade show in Indy last February. Being ever in short supply, I agreed to let them have my 38mm to try on their TM 300, as we are actively pursuing OEMs and had met with TM last November. So we saw it as an opportunity to get some very credible third party data.

The Grose jet inlet was far from dialed and so that was some of the first issues they had, because it definitely acts different than the Mikuni tapered needle and seat. After getting it satisfactory (and it's a one off) because they are tuners they started working with different fuels and oils/mixtures. There are gains to be had by any custom tuning so we decided to continue to work with CP and provide them custom metering rods. All this collaboration just makes you the end user the winner and a lot of what we discover will wind up as future revisions. Corey

 

[Corey]

I did that

Trying to get some shirts and swag to you this weekend while in Denver and at the Peak. How would be best to go about that? Corey

 

[Diggs345]

I had just installed a Grose jet inlet in my personal 38mm for my GG 300 for testing. I met MikeS and Michael at the trade show in Indy last February. Being ever in short supply, I agreed to let them have my 38mm to try on their TM 300, as we are actively pursuing OEMs and had met with TM last November. So we saw it as an opportunity to get some very credible third party data.

The Grose jet inlet was far from dialed and so that was some of the first issues they had, because it definitely acts different than the Mikuni tapered needle and seat. After getting it satisfactory (and it's a one off) because they are tuners they started working with different fuels and oils/mixtures. There are gains to be had by any custom tuning so we decided to continue to work with CP and provide them custom metering rods. All this collaboration just makes you the end user the winner and a lot of what we discover will wind up as future revisions. Corey

Is that the needle you offered me Corey ???

 

[drehwurm]

If resetting the float tang made that much difference then your floats have had a small leak all along.
...
I normally suggest a float check when someone is having issues like you described and thought we had discussed. Anyway glad to see you are starting to get good results like the others.

I suspected the floats (or float valve) right from the start and yes, you suggested checking the float level after I initially described my issues. The ~20mm I was getting fooled me all the time into believing it was just fine. That's why I like to keep posting about my issues - others may find this useful.

I really do believe the SC will be an advantage at the Romaniacs with its constant, smooth power delivery under varying conditions to support my inferior riding skills. Though despite all my testing hours I still think it is a bit of a risk, but I believe in the concept enough to take that risk!

Michael

 

[Corey]

Is that the needle you offered me Corey ???

You talking about the metering rod or the fuel inlet. Not custom MR just carefully measured.

 

[drehwurm]

BTW, are the guide pins for the floats just pressed in? The one-piece float of the Keihin PWK seemed to be a surprisingly good fit when I checked. Seems possible to make a conversion, but I'd need to remove the stock guide pins.

Michael

 

[Corey]

I suspected the floats (or float valve) right from the start and yes, you suggested checking the float level after I initially described my issues. The ~20mm I was getting fooled me all the time into believing it was just fine. That's why I like to keep posting about my issues - others may find this useful.

I really do believe the SC will be an advantage at the Romaniacs with its constant, smooth power delivery under varying conditions to support my inferior riding skills. Though despite all my testing hours I still think it is a bit of a risk, but I believe in the concept enough to take that risk!

Michael

I appreciate your faith in the SC. They really are pretty trouble free once sorted, certainly less things to fail than on a Keihin/Mikuni. I wish they all were perfect, but we seem to have a little scatter yet as far as quality control. Working hard to make it right with all.