Nitro car running weird when getting hot

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I imagine someone noted this but if not the problem sounds pretty simple. You are encountering a lean condition.

By that often it takes an engine a tank or two to read "operating temps". This engine includes (I have few of them myself). Engine should be quite rich for the first 1/2 tank then slowly it will mean itself out until it stabilizes. That is when you evaluate the tune. So if you think about it, if the engine is optimized right after you start it that is not always ideal. Additiobally chabge that clutch bell. Grease can become baked on. When it's cool you can't see it. However when that bell gets 500-700 the grease melts and clutch slips. You can take a blow torch (careful!) and apply it to see what I mean.
 
I imagine someone noted this but if not the problem sounds pretty simple. You are encountering a lean condition.

By that often it takes an engine a tank or two to read "operating temps". This engine includes (I have few of them myself). Engine should be quite rich for the first 1/2 tank then slowly it will mean itself out until it stabilizes. That is when you evaluate the tune. So if you think about it, if the engine is optimized right after you start it that is not always ideal. Additiobally chabge that clutch bell. Grease can become baked on. When it's cool you can't see it. However when that bell gets 500-700 the grease melts and clutch slips. You can take a blow torch (careful!) and apply it to see what I mean.

i was out yesterday and did some testing.
i have tuned it to a rich setting and a lot of smoke emerges from the pipe, both when idle and when throttle.
But when it get's hot and starts running weird, the smoke disapears, it all of a sudden get's very little fuel, i tried turning the low speed counter clockwise to give it more fuel, but i had to turn it to a very unreasonable amount. The car got a better sound at first, but it couldn't handle having the lowspeed so far out
 
Ok. How do you know you have it tuned to a rich setting? It's obviously subjective so post up a hard pass letting it come to idle for 10 seconds. This is how I analyze my engine''s tune and not sure how else -"anyone can give feedback other than seeing/hearing it. When I was learning to tune that's all I did was send clips to these dads of their "pros drivers" pleading for their feedback. I figured they were the ones putting it down week after week. Some of them were brutal with me but In hindsight leaned they were the ones who ended up being full of ***.

Anyway based on what I've read it sounds straight up like you are lean. But we won't know until we see it, right?

Also to what do you account it running optimized and then "weired". Think through the logic. If you are happy with it then go bump that (still love to see I) and if it's still not tuned then be careful of selective listening , you know?
 
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How much fuel has been through it, how's the compression? It sounds like the pinch may be gone, when it warms up the piston loosens up and then you can't tune it.
 
Shrodemode has got a point!

Also .make sure the fuel tank is clean an internal fuel filter isn't clogging or restricted.
An your tank is being pressurized by the the tube from the muffler....:cool:
 
How much fuel has been through it, how's the compression? It sounds like the pinch may be gone, when it warms up the piston loosens up and then you can't tune it.
1 liter max i think, i think the compression is somewhat fine, it has somewhat of a ressistance when you pull it, i need to hold it down with one hand, not too hard but a bit. this thing you're suggesting, what parts are we talking about here, what do i need to buy to fix it if that's the problem?
 
1 liter max i think, i think the compression is somewhat fine, it has somewhat of a ressistance when you pull it, i need to hold it down with one hand, not too hard but a bit. this thing you're suggesting, what parts are we talking about here, what do i need to buy to fix it if that's the problem?
I agree with @Rolex, a liter is still pretty new and it should still have plenty of life left as long as it hasn't been over heated. Pull the engine and turn it over using the flywheel instead of the pull start. It should be relatively hard to turn over and it should be obvious when the piston goes past the upstroke and back to the downstroke. Another way is to remove the cooling head and then slowly turn it over, in MOST engines with that still have good pinch the piston will actually push the sleeve up and out of the block.
 
I'm still confused with your symptom. Originally it looked like you said it starts out well before the end of the first tank it act "weird". Then you stated it starts off rich then gets hot. Hot is subjective so assuming you have. It figures it out what is it actually doing. Forget temps it means nothing when it comes to performance. b I'll asks again what is weird? If it is a lack of compression I wouldn't sweat it. I have five engines that have no compression. ALL of them scream their tits off. The sympton is once it's tuned it won't idle adjusting the head cleatence solves this.
 
I don't think anyone has mentioned this yet... Make sure your fuel is fresh and has a good oil content etc... Old fuel will make you crazy trying to tune. Also, with all The messing around with your needles, is it possible someone overtightened them and crushed one? Also the seals do crack and break. Always check to be sure the carb is tight on the motor. Short of that, I think everyone else has covered everything. I am a big fan of K.I.S.S. (keep it simple stupid!) look for the easiest fixes first. If nothing else it's peace of mind that things are right and it's not a lot of work to get that peace of mind.

These things can cause a lean effect (not so much the bad fuel). Also, I beg to differ. Hot is NOT subjective when you use a digital thermometer. I don't know why they arsnt sent with the Damned cars or engines yet. They are non-optional IMO.
 
I'm still confused with your symptom. Originally it looked like you said it starts out well before the end of the first tank it act "weird". Then you stated it starts off rich then gets hot. Hot is subjective so assuming you have. It figures it out what is it actually doing. Forget temps it means nothing when it comes to performance. b I'll asks again what is weird? If it is a lack of compression I wouldn't sweat it. I have five engines that have no compression. ALL of them scream their tits off. The sympton is once it's tuned it won't idle adjusting the head cleatence solves this.
16645bf53d6d5c381277295e56db2bff.jpg
 
Agreed with the post above about fuel delivery system. Spoiled fuel will normally cause the engine to cut out regardless how high your idle is set. Tanks are maintenance item for me so agreed a prequisite is to ensure that the fuel delivery system is sound as it can wreak havoc. Were all still just trying to guess of course. it's difficult to truly say withiout seeing it.
 
Agreed with the post above about fuel delivery system. Spoiled fuel will normally cause the engine to cut out regardless how high your idle is set. Tanks are maintenance item for me so agreed a prequisite is to ensure that the fuel delivery system is sound as it can wreak havoc. Were all still just trying to guess of course. it's difficult to truly say withiout seeing it.
ASM2suit-625x833.jpg
 
Whacks on, whacks... Eh, you know what I'm saying... :D
 
Lmao! And I always thought the 'lunchbox' was a tamiya design. Handles!!! :naughty:
 
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