Bog or sputter?

[Carbon]

Hi,
I picked up a new 4.6x a few weeks ago. I got inspired from a friend. The thing works great for the most part besides some noob mistakes.
Anyway.. I went for a rip last night and i had the thing running awesome. It went faster than i've had it going and i was getting some decent wheelies.
The thing that I'm wondering about is a couple times when I was braking into a turn and gassing it coming out of the turn, sometimes it would sputter or bog out for a second. It happend only a couple times. Once on the straight from slow speed to a quick accel. too.
I didnt have it too lean cause i had a decent ammount of smoke, and my temp was running around low 70*c to high 80's.
I was also around 1/4 tank of gas or abit less.
If you have any imput, it would be greatly appreciated. thanks

 

[Double-O-Zilch]

Please state your times in F as I am behind the times. LOL. I think it sounds like the old half tank lean problem. Also you may be running a bit rich on the low side. There are many ways to check this but the easiest in my opinion is the pinch test. Try pinching your fuel line an inch above your carb inlet. If it dies right away, it's too lean. If it takes awhile to die, it's too rich. It should increase rpm a little then die out. This may help you out, it explained a lot to me.
https://www.hpisavageforum.com/forums/showthread.php?t=3657&highlight=tank+lean

 

[Carbon]

Thanks, I'll have to give that a try.

 

[Double-O-Zilch]

Try leaning your highspeed needle too, I just check your temps on a conversion chart and you seem to be running low. Adjust your high speed then the low speed. Always make sure she's smoking and drive it around so the changes take effect. Don't go above 250f for now.

 

[Fx]

Yeah your problem is quite common. Your low end is too rich. This is why it was bogging when you tried to accelerate. The engine just couldn't "drink" all the fuel it was getting which is why it "gurgled". Turn your low end clockwise 1/4 of a turn and see it that helps. Don't be afraid to give it a couple more 1/4 turns until you see improvement in acceleration.

BTW-
70-80 degrees Celsius = 158-176 degrees Fahrenheit
Your running too rich, lean the low end out 1/4 of a turn at a time first to improve acceleration. Check your temps then lean the high end out 1/4 of a turn at a time.

Try to get your temps between 95-115 degrees Celsius

 

[Double-O-Zilch]

Atleast your smart Fx! My learn'n ended years ago. LOL

 

[Fx]

If you can't dazzle'em with brilliance, baffle'em with B.S.!

Sound familiar? lol

 

[Carbon]

Thanks for the info guys. I'll try it out tonight.:beer:

 

[MTBikerTim]

I would tune the high speed needle first. I think you want your temps to be around the 115c mark. Low temps are a good sign though cause it's easy to get the temps up where as it's usually a lot harder to get them to come down.

 

[Carbon]

With that half tank lean thing, would you recommend doing the tuning with a full or quarter tank?

 

[Fx]

With that half tank lean thing, would you recommend doing the tuning with a full or quarter tank?

Fill it up the the shelf, a.k.a. fill it up half way.

 

[ntenc1]

HOw are you taking your temps? At the GP? Also smoke will fool you sometimes. It depends on what percentage of oil you are running as well. If you are running 8-10% oil you will not have as much smoke of course if you were running 12-16%. What nitro/oil % are you running?

 

[Carbon]

I'm taking the temp's with a temp gun pointing it at the GP and sticking it as far as i can in the heat sink. I took a few to try to get an average. As for fuel I never actually looked that close. Its 20% nitro though. I just got what the guy recommended at my LHS. I can look this evening.