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Carb setting?

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Y

yveschew

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hi, i have Revo 2.5r engine and i have lost the carb setting can anyone tell me what the factory setting actually the Low Speed Neddle how many turn from close because my revo dead after full throttle.
 
hsn is 4 1/2 from close and lsn is flat with the barrel. Thats the stock settings. But sounds to me like you might have a little more going on there.
 
yes the lsn is flat with the barrel but the car still in bad acceleration. why?
 
I'm pretty sure the HSN is 4 turns out from closed. That should be a rich setting. From there you should lean it little by little (1/8 of a turn clockwise.) Always tune from rich to lean. Have you tried the pinch test to set the LSN?
 
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Actually it's not 1/8 turn at a time. I just scanned in the info that came with my new slayer here goes

picture.php


But I still think it's 4 turns out from closed on the HSN
 
hey , i need help to it's a 3.3about a half gal. through it but when it warms up it boggs on take off .could not figure it out so it's sittin on the table,same prob. 2.5. am i toasting these motors or am i doing something wrong ? they are not lean. good smoke.:\
 
Good smoke means the HSN is not too lean. It's possible that it's too rich.
What kind of temp is the motor running at? Usually if you're bogging down on take off, the LSN is too rich, you can try the pinch test to check the LSN setting. Get the motor warmed up, make a couple WOT passes to clear out any extra fuel. Bring it in and pinch the fuel line closed, the engine should rev up then die in 3-5 seconds. Any sooner and you're too lean, any longer and it's too rich on the LSN.
 
just found my on board temp,but haven't ran it yet will try soon i hope i think i'm going through withdrawls, wife had surgery trying to take care of her and the house and kids and work .not much extra time.should get better soon.
 
my engine still cut off when i stop immediately, i been retune many of time, why?
any idea but i have installed motor saver filter and trinity hi flow pipe. any suggestion?
 
It really doesn't take much at all to stop one of these things. Have you checked inside of your engine as well as outside of it to see if there's anything that could ever so slightly be binding it up? I had an engine that had a defective bearing that the crank shaft goes through. It was just enough to stop it every time I let off the gas. What's it look like inside and when it's running does it sound normal or does it sound like there's something more going on in there than just combustion?
 
nothin wrong and sound as normal. it might be the fuel mixture. if the fuel set too rich will cause the engine cut off?
 
yes, too much fuel will flood the engine, won't all burn off in time and eventually fill up. From all of the things you've mentioned though it doesn't sound like it's rich enough to be the sole cause of the engine stalling. have you tried making some changes to your idle screw at all? may want to try some very small changes to tighten the idle screw which would raise the idle of the engine. also, have you thought of an air leak someplace. One of your fuel lines might need replacing or the carb may not be tightened down onto the engine block enough. Not sure if that's what it is but they're both simple things to check and correct if they are the problem.
 
MrClean said:
Good smoke means the HSN is not too lean. It's possible that it's too rich.
What kind of temp is the motor running at? Usually if you're bogging down on take off, the LSN is too rich, you can try the pinch test to check the LSN setting. Get the motor warmed up, make a couple WOT passes to clear out any extra fuel. Bring it in and pinch the fuel line closed, the engine should rev up then die in 3-5 seconds. Any sooner and you're too lean, any longer and it's too rich on the LSN.
Click to expand...


Okay, i have a question, you might think its stupid butt here goes......with the pinch test, how could that be accurate, becuase say if you pinch closer to the carb, it would take less to shutt off, if you pinch farther away it would take more time shut off right?
 
sounds about right to me. personally, i've never done that test as a gauge on whether my engine is tuned properly or not. i don't even shut my engine down that way either. i put my finger over the exhaust pipe. i was told a while back that was a better way of shutting it down so as not to starve the engine of fuel ever. it may be for a second or two but over time it may add up. i know this is off subject. back to your original question, yes, i personally don't think it's an accurate barometer of a proper tune or not...
 
ajames942 said:
Okay, i have a question, you might think its stupid butt here goes......with the pinch test, how could that be accurate, becuase say if you pinch closer to the carb, it would take less to shutt off, if you pinch farther away it would take more time shut off right?
Click to expand...

I thought the same thing, tried it both ways and it shuts off at the same 'count'. The reason, I'm assuming, is because once you pinch it, you are stopping the flow of fuel all together. It's not pulling the fuel from the point you pinch, the fuel will actually stay in the line, it's burning what fuel is in the engine. I think when you do it, what happens is you cut off the vacuum created by the engine and the exhaust feed to the fuel tank. Try it and you'll notice that no matter where you pinch, the line stays full of fuel, both before and after the pinch point.
I think that's why you can tell how your LSN is set, because that will give you a ballpark idea of how much fuel is in the engine when the line is pinched. I don't use this technique anymore, I adjust the LSN based on how the rig takes off from a stop.
 
MrClean said:
I thought the same thing, tried it both ways and it shuts off at the same 'count'. The reason, I'm assuming, is because once you pinch it, you are stopping the flow of fuel all together. It's not pulling the fuel from the point you pinch, the fuel will actually stay in the line, it's burning what fuel is in the engine. I think when you do it, what happens is you cut off the vacuum created by the engine and the exhaust feed to the fuel tank. Try it and you'll notice that no matter where you pinch, the line stays full of fuel, both before and after the pinch point.
I think that's why you can tell how your LSN is set, because that will give you a ballpark idea of how much fuel is in the engine when the line is pinched. I don't use this technique anymore, I adjust the LSN based on how the rig takes off from a stop.
Click to expand...

ahh ic ic....makes sense now..
 
Did you guys have any luck so far? The posts in this thread should get it done. Let us know how you're doing.
 

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