Have your balls dropped (smart carb)

[the gman]

Just a fyi,
Ran smart carb first ride on my 300, ran great but after shut down motor flooded. Next time out ran like sh t and flooded 3 times after stopping for a while. Buddy's bike had problems starting bike also with smartie. This is what I did to fix MY problems. Remove the floating balls. Ran my bike two rides so far and wow......it works. My thought is floaties stick and plug vent lines that are realy float bowl pressure lines. If you shut off your bike and balls are stuck closed, the fuel being warmed from your carb heat expands and forces fuel up noozle that is submerged in fuel ie floodes bike. Also bike did not miss a beat both trips where before it would run great then stumble then run great again. I am running a 40 with the q5 and my wot egt temps are still to hot. Now if I can get this controlled....hope this helps other smart carb users.

 

[ds2154]

38 vs 40

Gman, did you ever end up trying the 38 with the Q5? I thought that was the solution for the 300? I have the Q5 on order and have been riding my 450 until it shows up. I may have to give up on the 2 stroke if the 38 is not the right fit. Not enough time left in the season to wait for a 40!!

As always, thanks!

 

[Northwestguy]

Love the posting title.
Genius!

 

[the gman]

Ran the 38 first with the. Q11 then went 40 with q 9, then q5. If snow was better would of had more testing done by now. May borrow buddy's 38 to try as he has removed his 38 smarty on his non ported 300 but is keeping it for summer use. He got fed up with not being able to get a needle, which I can't blame him. Are we the only ones having flooding problems when we shut off bikes for lunch. Or just the only one willing to admit it.....

 

[mxracer299]

You're spot on, drop your balls... lol When you're doing a good pull the inside of the carb is super cold, when you shut it off the hot heater and outer part of the carb heat soak the entire carb, when the cold fuel in the float bowl heats up and expansions its pressurized and the floating balls raise up enough to plug the vents. So yes pull the float in balls and it gets rid of that flooding issue. The other thing is cold starting as you know isn't the best, I carry a 1oz squirt bottle of fuel and i lift up the prefilter and give it a good squirt of fuel and it fires right up, its needs a larger choke circuit.

As far as 38mm vs 40mm goes, the 40 pulls slightly more on top but the 38 absolutely rocks on it too, you cant go wrong on either one, its not a huge difference. If you have a 38 i wouldnt sell it to buy a 40 unless youre worried about maybe 1hp on top, maybe... Im going to try a 40 but it runs so good with the 38 that im very skeptical that it will loose some of my mid range hit.

Im running a Q05 in my 38mm and I'm trying a Q07 in my 40mm. Unless you have a whole lot of engine work done the 38 will need a Q07 for most bikes.

 

[the gman]

Glad to here we weren't the only ones flooding. If this carb didn't work as good as it does,when it ran right, I would of sent it back a month ago. These carbs worked fantastic (for buddy's) all summer. Anyway I am running the 40 with the q5 (.074) at 85 clicks from rich to try and get my temps under control. Bike ran idle to 3/4 at about 95+ clicks but temps rose to fast in a climb. Bike burbles idle to 3/4 throttle but performance is through the roof at the richer setting. I need Corey to get me a needle that I can set at 95 clicks but is like .070 on the tip. I think we are loading these motors more and longer than the dirt riders. just remember remove these floaties at your own risk. ive heard of guys pulling plug, checking for spark, fuel squirts out, spark plug Sparks and then your balls are on fire nuff said

 

[mxracer299]

What are you running for mods on your 300? I was kicking around the 5 but I put a 7 in to run this weekend. Maybe I should throw in the 5 to be safe...

 

[ds2154]

Thanks for the replies...

Quick question, if you pull the float balls out, will the bike flood if it tips over? Isn't that what the balls are for?

I guess I'll keep waiting for the Q5 metering rod and put it in the 38. I have done quite a bit of engine work, so hopefully that will be the magic piece for my 300!

Thanks again!

 

[mxracer299]

The steel balls should keep it from flooding when tipped over, it will flood if your float sticks open though. I would turn off your fuel any time its not running just to be safe. One thing we've figured out with the 300s is that even with very similar builds they all run different and they all run different metering rods, I keep a 5,7,9 and 11 just to be safe. And the bikes that have most of the stuff done but not all of it dont run much better than stock, the difference between bikes that have most of the stuff and ones that have all the stuff done is drastic, a few small things can make a big difference!

 

[wwillf01]

The steel balls should keep it from flooding when tipped over, it will flood if your float sticks open though. I would turn off your fuel any time its not running just to be safe. One thing we've figured out with the 300s is that even with very similar builds they all run different and they all run different metering rods, I keep a 5,7,9 and 11 just to be safe. And the bikes that have most of the stuff done but not all of it dont run much better than stock, the difference between bikes that have most of the stuff and ones that have all the stuff done is drastic, a few small things can make a big difference!

Are you finding the same in the summer? Is everyone running into rod issues once winter starts?


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[mxracer299]

You can run a step leaner on the rod to clean up the bottom end, you can't hold it WOT long enough with enough load to get super high egts on dirt, actually these fully modded bikes suck on dirt, they have way too much power to be ridable, I have a 250 cylinder for dirt. It also doesnt flood because you dont have super cold internal temps with hot external temps.

 

[wwillf01]

You can run a step leaner on the rod to clean up the bottom end, you can't hold it WOT long enough with enough load to get super high egts on dirt, actually these fully modded bikes suck on dirt, they have way too much power to be ridable, I have a 250 cylinder for dirt. It also doesnt flood because you dont have super cold internal temps with hot external temps.

I personally love my fully ported sx 300 for the summer... But I do ride from 4000ft up to 11000ft so there is some hp loss there and I am a pretty big guy... For me though it is a better trail machine with all the sx upgrades and porting because of the wider rpm range... Hell I even use the red exhaust spring in the summer it just makes the wheel easier to loft up and over things


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[the gman]

My 300 has gore porting,Sx head,and Sx cdi box. I have noticed a BIG mid range power increase with the bigger needle. I don't doubt mt. Doo but I still think more air needs more fuel. If a 38 needs a q 5 a 40 needs a q 3. But they don't make one. Tempted to borrow buddys 38 but I am to the point I just want to ride. As far as the floaties keeping you from flooding, think again, if your needle sticks open, after the green floaties stop the flow, the fuel WILL seep past the noozle into the intake, just not as fast. Now I want to clarifie, I am removing the little green balls that are in the tip over valves, NOT THE FLOATS in the float bowl.

 

[mxracer299]

I thought the same thing and so did he, its just not working that way for whatever reason, the bigger carb has to be pulling more vacuum, it doesnt make much sense but his bikes had to be leaned out with the 40s compared to the 38mm to get proper egts. My Q05 is borderline lean on the 38mm, if the 40mm needs more fuel I'm SOL for running it, i'll know more after this weekend. The 40mm I'm running has no anti tip over valves period, it has just has brass nipples where the tubes go, i'll see how it works. I'm running a Munn motor with the 13 style head with a different cut on it, but I have to run some race gas for det, sx ignition, pc pipe, boyseen rad valve with the race spec reeds in it, red spring 2 1/2 turns in. It is quite a bit different power than the Gorr motors, it has a violent midrange in comparison and a little less on top, that's where I'm hoping the 40 will help out. Tune, tune, tune... that's the joy of build in a 2 stroke. Haha But they sure do rip!

 

[wwillf01]

I thought the same thing and so did he, its just not working that way for whatever reason, the bigger carb has to be pulling more vacuum, it doesnt make much sense but his bikes had to be leaned out with the 40s compared to the 38mm to get proper egts. My Q05 is borderline lean on the 38mm, if the 40mm needs more fuel I'm SOL for running it, i'll know more after this weekend. The 40mm I'm running has no anti tip over valves period, it has just has brass nipples where the tubes go, i'll see how it works. I'm running a Munn motor with the 13 style head with a different cut on it, but I have to run some race gas for det, sx ignition, pc pipe, boyseen rad valve with the race spec reeds in it, red spring 2 1/2 turns in. It is quite a bit different power than the Gorr motors, it has a violent midrange in comparison and a little less on top, that's where I'm hoping the 40 will help out. Tune, tune, tune... that's the joy of build in a 2 stroke. Haha But they sure do rip!

I can tell you guys this if the smarty does not work out maybe go the Lectron route... Hell a 36 works for me in the summer in the 300 and it has an adjustable power jet for the top end.... I turn this up at the dunes... I will be trying a smarty shortly here on the 300 and will let you know... It works well on my cr500...


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[the gman]

Racer were your upper tip over valves seats tapered or flat. Reading on ktm Corey said they should be flat not tapered as the tapered were more prone to sticking when the floaties got wet. The ones I have pulled were tapered, the new ones I bought were flat. You have also removed the steel balls?? Why?? Have you seen the fuel mixture change because of that.

 

[mxracer299]

Its a long story but the 40mm I got doesn't have any tipover valves as it was for a different application, I am going to try it and see how it works. I can get the tubes and steel balls if need be, I just have to be diligent about turning the fuel off if its upside down. This weekend will be the first weekend on it. Im going to run it just to see what the performance difference is. The 38 runs very well as it is so I'm not expecting much, these engines are really sensitive to small changes though so who knows.

 

[the gman]

Seems like all the smart carb story's are long storys. My gas gas last year was set up in Montana with the q11 and when I got it home ran way too lean, not to mention carb ice issues. Now the ice is cured thanks to mt. Doo and avid and I still can't get egt temp in order. I think I should of stuck with the 38. I have to keep telling myself I am on this bike because they are so much fun in the trees. Then I go back to my old ways of more power is better(snowmobile days). Old habits are hard to break.

 

[dirtrebel]

Seems like all the smart carb story's are long storys. My gas gas last year was set up in Montana with the q11 and when I got it home ran way too lean, not to mention carb ice issues. Now the ice is cured thanks to mt. Doo and avid and I still can't get egt temp in order. I think I should of stuck with the 38. I have to keep telling myself I am on this bike because they are so much fun in the trees. Then I go back to my old ways of more power is better(snowmobile days). Old habits are hard to break.

just try the stock carb then tell me how much better the smarty is! once I got my smarty running decent I went from burning down at 7000 feet to pig rich bogging at 9000! what a joke! stocker runs great from 5000-9000 feet! oh and its not my engine health either! oh yeah my balls are still up inside my abdomen from being water boarded with smart carb kool aid and then kicked in my tipover balls repeatedly, lmfao!

 

[mxracer299]

Yeah it doesn't seem to work very well on your yamaha, not running a TPS sensor must be causing issues for you. Mine runs really well, I'm just always searching for more power. Haha Ive ran from 3-12,000ft and its always ran very consistent. GMAN, what have your plug readings been looking like, I dont trust EGT gauges as far as I can throw them, I've seen a few brand new Kosos fail to read properly this year. One of my buddies had his reading 200 degrees over what it should, it was causing him fits trying to tune his bike.