engine makes popping sound

[Erik J.]

My engine from the xt makes a popping sound when it runs idle.can it be to lean mixture of the needle on the carb or bad spark plug?I also installed a killer bee v1 and i oiled the air filter.Maybe the killer bee glitches or the oil in the filter keeps air from flowing in?


I'm almost done with breaking in the engine but i still run on 1/20 mixture because i mixed 5 liters of fuel.There comes little smoke out the exhaust when it runs on 1/20 mixture.


maybe with this info anybody has an idea what the problem is.

 

[Deluge]

It could be an exhaust leak. Check your gasket.

What is your low speed needle set at? If it's still at stock settings, it's fine. If you tuned it, try turning the low speed needle an 8th counter-clockwise and see if that helps.

Is your spark plug tight? Is there any sign of damage?

If you think it's the kill switch, try disconnecting it and see if the popping stops.

How do you oil your filter? I use the following method.

Proper oiling is crucial to the operation of foam filters. The following is one recommended method of properly oiling filters -

Saturate the filter with a tacky foam filter oil. A clear plastic bag or container can be used to literally soak the filter. Disposable vinyl gloves are useful to initially to squeeze as much of the oil back into the container / bag for future use.

Then continue to remove as much of the oil by squeezing (not wringing) the filter in paper towels.

Squeeze hard, and keep using clean towels until almost no further oil is staining the towels.

With this method, it can safely be assumed, as far as is possible, that every open cell is coated with the tacky foam filter oil, and every cell is open to pass air.

The filter can be over oiled just as easily as under-oiled. Too much oil left on the foam fills the open cells, and will prevent the passage of air, effectively choking the motor. An under oiled filter will breath fine, but can allow dirt into the motor.

 

[Erik J.]

It could be an exhaust leak. Check your gasket.What is your low speed needle set at? If it's still at stock settings, it's fine. If you tuned it, try turning the low speed needle an 8th counter-clockwise and see if that helps.

Is your spark plug tight? Is there any sign of damage?

If you think it's the kill switch, try disconnecting it and see if the popping stops.

How do you oil your filter? I use the following method.

What is the best way to check the gasket of the exhaust?

What do you mean with the spark plug tight?In the cylinder head?If so i will check that and if it's damaged.

The carb is still in stock settings but also when it runs idle the car is rolling a little bit so maybe set the low speed needle a little bit richer?But i will do that when i checked everything else.

I pulled the plug from the killer bee out of the receiver but the engine didn't start and when i put it back in it started in one pull so do i need to remove the killer bee and the cables?

I did oil the air filter and i squeezed it out but i didn't use a towel so i will clean the air filter again then oil it and at the end use a towel.

 

[Deluge]

If it's an exhaust leak, it'll leak oil where the exhaust meets the head.

Make sure the plug is tight in the head. Pull the plug wire and see if you can snug it up. If it's tight, leave it alone and don't try to force it, or you'll strip out the threads. While you have the plug wire off, check the plug for any cracks or damage.

If it rolls at idle, the low speed needle is too lean. Richen it up about an 8th of a turn.

To test the kill switch, disconnect it from the receiver and disconnect the wire that goes from the engine to the kill switch. But since you said it rolls at idle, I doubt it's the kill switch. It couldn't hurt to test it, though.

 

[Erik J.]

I looked and the rubber that is between the exhaust and the Motor is broken.maybe that's the popping sound

 

[Erik J.]

does anybody know what I can replace the silicone tube with for the exhaust?

 

[Deluge]

Are you running the stock can? If you are, you could just take the tube off. It's just there to route the exhaust, and it's restrictive. You're better off without it.

 

[Erik J.]

it's the tuned pipe from redcat with double tips









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[Deluge]

Try an auto parts store. They have high temp tubing that'll work. Just take the pipe with you so you can test fit it.

 

[Erik J.]

what pipe do you mean.from a radiator or something?

 

[Deluge]

A straight piece of high temp silicone hose. They sell it by the foot.

 

[Erik J.]

I have found tube that's Goes To 200 Degreese. is that's any good?But internal is 25 mm

 

[Erik J.]

what is the +/- temp what comes out of the engine?

 

[chadj1980]

alot higher then 200 degrees... you can get the silicone hose at almost any parts store...

 

[Erik J.]

yes but i'm looking for tube but the best i have untill now is 250 degrees and 600 degrees but that is a rvs tube and ik don't know if that is gonna fit. The stock tube also melted and now i need a replacement part for it.The part cost 16 euro's here at the rc store but it also melts away

 

[Erik J.]

I fixed the silicone part and checked everything if it leaks but the engine still makes a popping sound.maybe it's because the low end needle is to lean?the stock gas cap is broken.a rubber part in the cap is cracked so I got it out maybe I got vapor lock?someone got an idea?

 

[cordy]

Make shure your carburator is tight no air leak. Also make shure your header pipe is tight no air leak.Make shure your carburator breather is clean,its right behind your air filter,its a little metal plate with two tiny screws,blow it out with compressed air.Yes vent your gas cap.

 

[Deluge]

Richen up the low speed needle a bit. Did you check the exhaust gasket?

 

[Erik J.]

The exhaust gasket is completly dry.i richend the low speed needle.now the popping sound is à little bit less but i need To drive à little bit To hear If its still there.i Will check the airfilter If its clean and i Will update To you If i need Some help.

 

[Erik J.]

there is no little metal plate behind the air filter.only the choke and that is clean because is as good as new 4 month old.what do you mean by venting the tank cap?there is already a little hole in it.