hi guys,
ive been getting quite a bit of popping from the exhaust lately when decelating on my 1998 evo sportster 1200. anyone could please tell me where to look at ?
much appreciated! thanks

 

Popping usually means the bike is running lean. Change anything recently?

 

not really, apart from that i mounted my original exhaust back on again, which have the silencer plugs removed. im not sure if i also had the decal pop on the previous exhaust to be honest.

thats the only thing ive changed

 

Exhaust joint leak?

 

Check for exhaust leaks or cracks.

 

Did you use new gaskets when you replaced the exhaust?

The gaskets are not reusable, once used they must be replaced with new ones.

Also if care isn't taken when installing the exhaust, the gaskets can easily get damaged and they won't seal properly.

 

When is the last time you changed your intake manifold gaskets. Vacuum leaks will cause a lean condition, leading to decel popping. What jets do you have in your carburetor? How many turns out is your Idle Mixture Screw?

John

 

Check your plugs (color and condition) to see the lean vs rich vs just right operation.
Popping on decel is normal especially if you have a carb and aftermarket exhaust. It is not usually harmful. Let the plugs show you the way.
Plug Condition Diagnose

 

One easy way to tell if it's from running lean is to open your enricher small amounts and see if it goes away. One of the benefits of having a carb bike. That won't ell you why it's running lean, but will tell you if.

 

I had the same thing happen to me.
Turned out to be loose nuts on the front exhaust.
I tightened them and everything was fine...for about 50 miles and it started again.
Checked and the nuts were loose, again.
Bought some new nuts, about 10k miles ago, everything is still fine.