Dung dung sound at low,,,,loaded rpm

BucKat

~SPONSOR~
Mar 27, 2002
271
0
Not sure what's causing this..

At low rpm ,,,,, throttle chopped,,,,with the engine loaded as in going down a hill with the throttle closed,,,,,, I get this terrible "dung dung" sound coming from the engine....No ,,,not the pipe,,,the engine.

Can't be good.

Help..


Buc
 

BucKat

~SPONSOR~
Mar 27, 2002
271
0
Piston slap....most likely not.
KIPS..............absolutely not.


It sounds like,,,,,,,,now I'm guessing here,,,,,,,,, detonation.

It's a real hard DUNG,,,,,Dung,Dung...


It is a DUNG sound not a knock or a ping sound.


Buc
 
Last edited:

BucKat

~SPONSOR~
Mar 27, 2002
271
0
Well,,,I have read a lot of posts on this and several other sites.

Conclusion...Knocking due to either:

1.excessive carbon on top of piston or on cylinder head.
2.poor fuel or too low of an octane rating.
3. bad bearings etc.... possible in my case but highly unlikely.

I will pull the top end apart and have a look. Drain the tank. Refill with new fuel and test on the weekend. I do use premium 93-94 grade fuel.
I will mix at 50:1 and jet accordingly ( instead of 40:1)..May help..may not but that's the route I choose to follow regardless.

Results posted soon.

Buc
 

BucKat

~SPONSOR~
Mar 27, 2002
271
0
Nope...

This is a very definite,solid DUNG coming from the combustion chamber.

It only occurs when the throttle is closed and the engine is loaded..
For lack of better description....the sound occurs during engine breaking..if a 2 stroke could.

Buc
 
Top Bottom