Ducati Monster Motorcycle Forum banner

1 - 9 of 9 Posts
G

·
Discussion Starter #1
2002 MS4 10,500miles
Leo Vinci High mounts with K&N Air Filter
FI, but no PCIII, yet

Problem:
When I let off the throttle and stay in gear I get poping in the cans.
 

·
Premium Member
Joined
·
147 Posts
I think popping on decel means too lean. Wouldn't opening the airbox make it worse?
 
G

·
Discussion Starter #3
I think popping on decel means too lean. Wouldn't opening the airbox make it worse?
This is what I origanally thought especially considering the aftermarket airfilter and pipes.

After some research, I found out the poping was a rich mixture, and gas finding its way into the cans then exploding.
 
G

·
Discussion Starter #4
This is a lean problem. Bikes come lean from the factory, then by adding a higher flowing air filter and exhaust you worsen the problem. Cutting a hole in the airbox will further push the issue.

If you're going to get a PCIII, find a good shop w/a 4 gas analyzer and a dyno, and you shuld be set.

Replacing the stock air filter could help a little, but I think at the end of the day remapping the fuel curve somehow is the way to go. If you are near sea level, a chip form Ducati Performance might help as well- just another option.

Anyway, hope that helps.
 

·
Premium Member
Joined
·
1,200 Posts
My 620 ran too rich after pipe and filter install with stock lid. Symptoms were that when hot, it was difficult to start back up right after shutdown. It depends on how the "BOX" deciphers the data fed it and reacts.
 

·
Registered
Joined
·
796 Posts
My bike does it but I run the bike kinda lean. I dont run it too lean but just on the lean side for better performance (I change the oil very often) I have had this with a few V-twins and it is usually a lean condition that creates popping.
 
G

·
Discussion Starter #8
the fuel map one your bike has 256 individual and totally un-related fuel points, 16 of which lie on the closed throtle line form 1000 to 10,000 rpm. it may pop because it is lean or rich, but most likely lean. they tend to go "bang" if too rich.

the fact it is too lean or rich on overrun has no relation to rich or lean anywherre else on the fuel map.

if you remove the airbox lid it will get very lean at wot in the 6 - 8,000 rpm range. probably won't make much difference to low throttle/cruise stuff tho. sounds like it just needs to be set up right for a start off, but some people seem to have a lot of trouble getting that done. which is a pity and somewhat annoying.
 

·
Premium Member
Joined
·
283 Posts
I have heard that bikes pop when lean because the too-lean mix occasionally doesn't burn at all, then that mix burns in the exhaust system. I'm sure others could explain it much better.
 
1 - 9 of 9 Posts
Top