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Throttle issue

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Kris407

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Orlando, Florida
RC Driving Style
  1. Racing
So when i am on the brake thebuggy idles okay and its all good but if i let off the brake, even though the carb doesn't open at all, it wants to haul ass. thats 1mm carb opening and it wants to really take off.

once i start driving it and i give it gas it produces a lot of smoke and stalls out but if i lean it enough it wont stall, but its pretty leaned out at that point on the high end andit wants to go fast when its idling. at that point i will richen the idle to stop the high idling speed which works but then it stall when you give it gas and i am back to square one. i cleaned out the carb and engine last night so there is no debris but i was thinking its still sucking air somewhere.
i will post a video of the problem tomorrow and i will provide the answer when its fixed but i wanted to hear some opinions.
 
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does the LSN control basically just the jump and then the high speed takes over? so can adjusting the LSN and/or HSN cause the high RPM and engaging of the clutch? when i had it on the stand and it was set to idle but it was really going like i had the throttle engaged, i could richen the LSN and it would throttle down until i could get it to idle perfectly. thanks Bamafan i will let you know what happens tomorrow.

will richening the LSN cause you to have to lean the idle more? will adjusting the LSN affect the HSN or just the idle?
 
The LSN controls idle and take off. the HSN takes over after about 1/4 Throttle. If your idle is crap inconsistent and high idle etc it's because your engine is starving for fuel. If your LSN is too rich it will idle but soon as you hammer it will die kinda like flooding the engine.
 
does adding after run oil affect starting it up the following day or should it only be used if you aren't using the model?

thanks for the answers :)

heres another question, what causes the pull start to slip? is it the bearing?
 
After run oil won't affect anything. It's basically only to keep the inside the engine and carb from rusting. If I am going to run say Friday, Saturday and Sunday I don't use it until Sunday. Everyone has there own preference though.
 
Reset back to factory. What does it do? And are you absolutely sure that the throttle gap is 1mm? Take the air filter off and actuate the throttle back and forth, does the carb-slide come back every single time to that 1mm gap? When breaking does the gap decrease?
 
Your one way bearing (OWB) is slipping if your starter slips. Take it out and slosh it good in denatured alcohol. Clean the crank that it rides on, as well.
Set your idle with full brake applied. 1mm opening is just a reference point. The proper idle is a balance of the correct LSN adjustment as well as the idle screw.
 
.. <---The space between those two periods is just about 1mm, is that how wide your carb-gap is?
 
well i put after run oil in it and i was going to start it again tomorrow that was why i asked about the oil interfering. the carb is absolutely at 1 mm and it slides back every time. i figured the good news is i can get it to start and get it to idle. i should have set back to factory but i was honestly playing with the needles while starting it thinking it needed it because it wasn't turning over and i got impatient.

i figure its the tuning i have just never seen such high rpms with the carb at 1mm and me not pulling the trigger but then again the throttle responds to the turning of the screws.

i will post video of it tomorrow before i start it and after so you can see what i am talking about.
 
I'm assuming you've broken in the engine already? Also if you don't have a temp gauge (get one) then a drop of water will tell you approximately where you're at. 212F is the boiling point of water and so if the drop of water really starts sizzling as soon as it hits the cooling head your to hot but it should evaporate fairly quickly. Not the best method, but its good in a pinch. The factory needle settings should have you running a bit rich. From there start with the HSN and lean it little by little until your top end is good, then move to the LSN.
 
thanks guys! yes i have a temp gun and when its on the stand with the high idle going and the wheels spinning (at what seems about 1/3 of the throttle) it of course runs as high as 250 degrees, like i am actually driving it but its on the stand and i'm not pulling the gas trigger. on the ground driving it is the same, after work i am gonna fire it up and video the tuning for you guys.
 
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...after work i am gonna fire it up and video the tuning for you guys.
Cool, you will have to upload to another service first though and then link to it from here (I believe).

Question, before your last post had you reset the needles to factory settings?
 
i did reset to factory but i played with the needles before i got it running because it was not starting. i will get it running in a few minutes and upload to youtube and then i will post a link.
 
I had a similar problem cleaned out my carb then still had to close the carb gap to like 0.4mm to get it to idle and that's with a rich lsn
 
i think you're right. i got it running and let the engine warm to about 175 which was easy cause of the high idle, then i reset to factory and had to lean the idle just a tad to keep it idling and it slowed down a lot. on the stand the wheels were turning but not nearly like they were and when i set it down it wanted to barely creep along, as soon as i give it gas though it bogs and dies.
i have video of it coming soon its uploading now.
 
I think in ur case ur gana have to lean out the lsn if it's bogging and just compensate by keep lowering ur carb gap as much as u can
 
the needles are responding to the slightest turn but it is doing a lot better!


 
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