New Conical Air Filters ... and the engine makes explosions

  • Thread starter Thread starter Erivaj
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Erivaj

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Hi,

Today I ride my Laverda Jota with the three new conical air filters (see photos).

When I open gas and accelerate, everything is ok ... but when I reduce the gas, I heard little explosions.

Why?  :(


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2011-02-16_19-37-28_472.jpg
 
Most probably because your mixture is now too lean, especially at low throttle openings. Did you adjust the idle screws to cope with the new filters?
 
Erivaj said:
No, I didn?t touch the carbs.

Hi Erivaj

the conical filters allow more air to enter the inlet mouth of the carbs at least at smaller throttle openings, so your carbs are now running somewhat lean because of the loss of the air box.

to fix the backfiring and improve the running generally, you will need to richen the idle mixture a bit with the idle mixture screws, and proably raise the needles one or two notches by moving the little clip on each needle DOWN one or two notches from where they are now

I wouldn't touch the main jets yet, they only affect running at wide open throttle, and won't have anything to do with the backfiring.

Most Laverda triples will run better with the stock airbox unless someone who really knows what they are doing sets the carbs up for the change to individual pod filters. The other piece of information is that those little individual pod filters just are not big enough to flow enough air for extended wide open throttle operation, if you are really determined to run individual air filters you should consider bigger oval filters with a much larger surface area to flow enough air for the engine at wide open throttle.

Paul LeClair
 
Forgot to tell you that there is a also another cause of such a problem with these filters: The rubber part coming onto the carb end can block the small progression and air holes located at the back of the venturi when the clamp is fully tightened. This is the case of K/N conical filters. Sometimes you have to use a cutter and carefully remove some part of the internal side of the rubber.
 
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