Boiling sounds after running on my .30

[son1cn]

Now when i run my .30 the temp goes up to about 250 no matter how rich it is, and when i shut the engine off, i hear a popping sound inside the engine and when i open the carb it sounds like something is boiling. What should i do?

[rocco79]

Did you seal the engine?

[son1cn]

what do you mean seal? i have all the seals intact, the carb, exhaust, pipe/header is there anything else? all the screw are tight on the top of the engine, what else could be the problem?

[Meatwad]

take the backplate off and put engine sealent on the edges

[Meatwad]

Now when i run my .30 the temp goes up to about 250 no matter how rich it is, and when i shut the engine off, i hear a popping sound inside the engine and when i open the carb it sounds like something is boiling. What should i do?

sounds like an air leak. check the tank o-ring and fuel lines

[Biodragen]

Try fryin some eggs on it---j/k

[Biodragen]

Take the mill out
Plug up the exhaust port with your finger.
Put some fuel line on the carb.
Blow into the tubing (while plugging the exhaust port) and spray all over the motor with a mild solution of soapy water concentrate on the carb and backplate areas---if you see it bubble---you have a leak.

what about the low end needle setting if you have temps at 250
Does it snap when you give it throttle and drop back down on the idle right away?

[Czech-it-Out Graphics]

he's prolly too rich, a motor can run hot when rich due to the unburnt fuel buildup putting stress on the motor

[Biodragen]

That was going to be the next thing I was going to mention

[AddictedtoNITRO]

bio- if you plug the exhaust don't you have to plug the carb too when checking for leaks?

[Biodragen]

Yep
sorry about that

[Thirdgen89GTA]

Not sure if this works as well on micro engines, but for full size engines spraying carb cleaner at the suspected leaking spots while the engine is running should change the idle if its got a leak.

The other way is definitely better, but this is a quick way to tell if you have a leak.

[SaVaGe_DuDe]

you know, it could just be fuel boiling in your carb. its very common ocne the engine gets hot. and if it is an alloy carb or something that will heat up easily, its makes it oh more common.

also, the temp going up should be rather normal. if the engine is broken in, the temp will clib to normal operating tempurature. However, i seal all of my enigne right off the bat, here is a link to how to do this. i found ti very useful when i first started r/c

http://savage-central.com/modules.php?na...ic&t=54465

although you may not haev that specicif enigne, its basicly the same process for all of them.

[motoxer4life]

i was just gonna write that it could just be your gas like savage said. mine kinda makes a boiling sound in the tank after i used up the whole thing.

[J-Dub]

I would try to seal up my TRX 3.3 but im afraid I won't get the backplate back on. When I put the bump-start backplate on it, one of the screw holes stripped out in the block, so I just put a longer screw in there and it made new threads once it past the olds ones, afraid if I take it out I won't get it back on. Heh

[Rawkfist_02]

Well if the engine is shut off at TDC, then you will hear the pressure escaping, but only momentarily.

[4wheelinrevo]

you know, it could just be fuel boiling in your carb. its very common ocne the engine gets hot..

only one thing, it doesnt seem to happen on the O.S. .30 as it has a rubber gasket around the carb neck that helps keep the fuel cooler.

i would say it is more likely a air leak

[Czech-it-Out Graphics]

im sure hes just running lean, if you start to get really lean especially like when the tank is run dry u might hear a sizzling if ur tune is way off as well.

[Thirdgen89GTA]

im sure hes just running lean, if you start to get really lean especially like when the tank is run dry u might hear a sizzling if ur tune is way off as well.

Son1c isn't lean. If anything he's on the lower side of rich, usually temping under 200* with plenty of smoke.

[Rawkfist_02]

Read my comment. My engines do the same thing.

[Czech-it-Out Graphics]

that doesnt mean he isnt lean, he could be really lean on the top end and have the bottom super rich to compensate for that. Temps really dont matter when it comes to telling if a motor is lean on one end, not knowing what kinda power the motor is making for him i would say he is lean on top.

[motoxer4life]

^^^ mike knows his stuff ^^^

[Rawkfist_02]

IDK what Mike just said, but I trust him. Rep for mike!

[Traxxas_Junkee]

Mike, get this kids some knee pads.

[Czech-it-Out Graphics]

i know dude lol but hey i dont mind i just put a bag on his head lmao JK JK