LooseCannon
Expert
Trying to determine the abnormal noise. Seem to have a noise that sounds similar to an exhaust leak or valve tick and or maybe the ECP kit noise. My thoughts were that if it had and exhaust leak the motor would back fire or pop similar to that of a car. Also thought it may be valve tick since there is no back fire or popping. Lastly thought it could be the ECP kit just being able to hear the motor run better. NOT SURE! Hard to get your head behind the motor while running. I have removed the skid and did the smoke test near the exhaust ports and found nothing. Didn't think the valves needed adjusted at 3,800 miles. Any ideas on troubleshooting or thoughts of noise. Obviously hard for someone to tell not being able to hear in person but was wanting some ideas.
:?
Thanks in advance!
:?
Thanks in advance!
impalapower
TY 4 Stroke God
I've been told it can be heard. Thats what you may be hearing.
LazyBastard
TY 4 Stroke God
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I've never heard of a car backfiring due to leaky exhaust... and I've driven with some of the leakiest exhausts on the road.
impalapower
TY 4 Stroke God
LazyBastard said:
I was thinking the same, but its been a while for me. Guess my stuff is too new.
Tom-RX1
Expert
I had a simmilar noise sounded like leaking exaust . I loosened the track and it went away . Only 200 miles since so it may just be coinidence . We pulled both mine and my buddys supentions out and got his track a little tighter than it was and now his has the noise .
Tom-RX1
Tom-RX1
LooseCannon
Expert
impalapower said:
Well I should clearifiy a Race car or any engine that has headers and horsepower. Ever have an evil backfire through the mufflers when you lift at the top of the dragstrip ? When the engine is decelerating, a header leak can suck fresh air into the exhaust. Once the air hits the fuel-rich exhaust gases and gets into the hot muffler -- blam! A race motor with headers will backfire or pop if there is a leak at the exhaust port on the heads, Not a leak at the rear muffler on your daily driver. Sorry for lack of info.
Still wondering what the noise is?
LooseCannon
Expert
Engine - backfire
Backfires in Exhaust.
Note:
It is normal for many high performance exhaust systems to moderately backfire or pop when the throttle is closed from mid-to-high rpm. In fact, one should expect a well-tuned high performance engine to "pop" and "crackle" when the throttle is closed at high rpm. The popping is a result of the air/fuel mixture becoming very lean when the throttle is closed and the engine is rotating well above idle speed. It is also necessary that the exhaust system have rather open mufflers for this to occur.
Why This (normally) Happens:
1) When the throttle valve is in the idle position, fuel does not flow out of the main system (needle, needle jet, main jet). Fuel is only delivered to the engine by the pilot (idle) system.
2) The combined effect of the closed throttle and elevated engine rpm is to create a fairly strong vacuum in the intake manifold. This vacuum, in turn, causes a high air flow rate through the small gap formed by the throttle valve and carburetor throat.
3) Under these conditions the pilot (idle) system cannot deliver enough fuel to create a normal, combustible air/fuel ratio. The mixture becomes too lean to burn reliably in the combustion chamber. It gets sent into the exhaust system unburned and collects there.
4) When the odd firing of the lean mixture does occur, it is sent, still burning, into the exhaust system where it sometimes ignites the raw mixture that has collected ---- the exhaust then pops or backfires
Other possible causes:
Air Leaks:
Any source of fresh air into the exhaust system can create or worsen the conditions that bring about exhaust popping. The most common entry point is the junction of the header pipes and mufflers. Even a small air leak can dramatically increase the intensity or likelihood of exhaust system popping.
Backfires in Exhaust.
Note:
It is normal for many high performance exhaust systems to moderately backfire or pop when the throttle is closed from mid-to-high rpm. In fact, one should expect a well-tuned high performance engine to "pop" and "crackle" when the throttle is closed at high rpm. The popping is a result of the air/fuel mixture becoming very lean when the throttle is closed and the engine is rotating well above idle speed. It is also necessary that the exhaust system have rather open mufflers for this to occur.
Why This (normally) Happens:
1) When the throttle valve is in the idle position, fuel does not flow out of the main system (needle, needle jet, main jet). Fuel is only delivered to the engine by the pilot (idle) system.
2) The combined effect of the closed throttle and elevated engine rpm is to create a fairly strong vacuum in the intake manifold. This vacuum, in turn, causes a high air flow rate through the small gap formed by the throttle valve and carburetor throat.
3) Under these conditions the pilot (idle) system cannot deliver enough fuel to create a normal, combustible air/fuel ratio. The mixture becomes too lean to burn reliably in the combustion chamber. It gets sent into the exhaust system unburned and collects there.
4) When the odd firing of the lean mixture does occur, it is sent, still burning, into the exhaust system where it sometimes ignites the raw mixture that has collected ---- the exhaust then pops or backfires
Other possible causes:
Air Leaks:
Any source of fresh air into the exhaust system can create or worsen the conditions that bring about exhaust popping. The most common entry point is the junction of the header pipes and mufflers. Even a small air leak can dramatically increase the intensity or likelihood of exhaust system popping.
race24x
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I have an exhast leak by the headpipe anyone else have seen this?
