310R problem maybe jetting??

[higdageese44]

Hello, I just finished installing a Pro-X 310 kit and 38mm Airstryker carb, I'm running a FMF Fatty Pipe and Power Core 2 Silencer, my jetting specs are 182 main, 52 pilot. I also am running 32:1 with Castor 927 mixed 50/50 with Klotz 113 and 93. My problem is the quad starts and runs perfect, the plug looks perfect maybe just a hint rich, the only problem is when ran at full throttle for 5-10 seconds steady it stutters almost as if its a lack of fuel, which I don't believe is right because I always believed the main jet was full throttle and the jetting looks perfect when checking the plug. Any ideas or help is greatly appreciated.

[x.system]

Close the plug gap and run it again, try .020. If you are correct and its jetted perfect this should clean it up but you can close the gap even further if its still there.

[Jason Hall]

Try a 175 main & be careful running It wide open at first. I hear so many people talk about checking the plug, or doing plug chops. If you don't use a brand new spark plug you wont get an even slightly close reading. If you know what 2 stroke rich feels like, then you will never have to look at your plug again. If you know what 2 stroke lean feels like you wont look at your plug again. A pre run spark plug takes a while to change color. You read a spark plug by looking down Inside of It, and locating a smoke ring. Not just according to color. It sound to me like you are rich. If you drop the main you will notice a big change. I learned how to jet my bikes by figuring out that going bigger main just causes more chuggle (feels like your running out of gas). I then went way lean knowing not to run wide open long. Lean will go boooowaaa then scream like nothing else. Hope this helps some.

Just for you Info, I do have a Pro-x 310. I drag race It, with a 40.5 ESR carb. My jetting will surpise most, but Is one RIPE RUNNER. 38 pilot- 168 main with FTZ, or Shearer drag pipe. I run HP2 at 42:1 not saying you will run that jetting, but I've had the same piston In It for 4 years with that jetting.

[higdageese44]

Thanks for the reply, I have done both, gapping the plug at .020 and putting in a 175 main jet, so my jetting specs are now, 175 main, 52 pilot, the needle I am not sure about as I forgot to check it. The guy I bought the motor off of gave me these jetting specs, 52 pilot, 182 main and DGH needle. after following the advice of Jason Hall, I believe 175 main is the way to go, but if anyone else with a 310 or advice would liek to chime in as too what you feel I should try please feel free as I'm dieing to ride this thing running at its full potential. For people who have not read my problem is that from idle to roughly half throttle it runs like a raped ape, but from, there on it wont pick up anymore it just bogs even when in neutral under no load you can put it full throttle and it just will not rev all the way up

[redrooster310r]

good stuff.... dont forget when running for a while in high gears pinned..not a jetting run ...dont just chop the throttle...could sieze motor.....always roll off....metering the fuel in stead of sudden stop. mainly duning or wot

[Jason Hall]

Might have stator trouble, I have an 89 trx that I built a sweet engine for, I was jetting that bike & could not get It to rev out. I found that the stator was breaking down on the top end only. My boys cr85 powered 3 wheeler would beat my R In a drag race. I realized after dropping the main down till I was sure It was to small, that the stator was messed up. swapped out the stator & It runs like the wind. If you keep dropping the main with no change, check the Ignition out good. Check all connections. Also make sure the plug boot Is threaded onto the coil wire tight. Check the ground In the rear of the frame. When jetting It I would not go any lower that a 168 on the 310. I built up a 310 for a buddy, his wanted a 165 main with the same carb as mine. Jetted his In the middle of summer & It was HOT 90 deg or so.

[speedfreek]

I have a 185 main in mine and it runs lean when racing. Didn't a stock R come with a 165? I would be scared to run a 175 main. Look at your spark, it needs to be thick and blue. Close the gap even more to around 17 or 18.
I think you mean you mix your gas 50:1, not 50:50. I run mine 42:1 with bel-ray H1R.
Try a hotter plug, I run a b8 or b9es. This is all on a 310. Hope this helps

[Aceman]

Aren't we getting the cart before the horse here guys? He stated he has a high rpm stumble "almost like a lack of fuel." I'd go through the fuel system before I started thinking about stator problems.

Is the carb new?
Is your tank venting? Vaporlock?)
Full flow out the fuel line?
Carb clean, float height checked?
You need to check the clip on your needle just to be sure.

After your fuel system checks out, I'd THEN move onto troubleshooting other things.