Lots of popping

[MASHMAN]

Hi all, long time no helloee, which I guess is a good sign that she's been running well for quite some time... however . The Prila has started to pop quite badly on low rev decel and sometimes threatens to stall on low rev accel. I'm used to a little popping on decel but she's started to pop pop pop pop pop pop pop pop, instead of pop decel decel decel pop pop decel decel. Something isn't right as when riding along it sounds like she is missing every now and then as I can hear: bum, steady throttle, bum, steady throttle, bum etc...

Any ideas?

cheers

Gordon

[Cajun]

last service?

dirty air filter?

life treating you okay Gordon otherwise?

[MASHMAN]

Hey Neil... not too bad here, just want the Prila sorted . All nice and lovely up norf?

Last service was 6 months ago... Air filter is clean, I've changed the plugs, stator looks fine (whew). Am starting to wonder if another battery has bitten the dust although I have a Motobatt in and it only reads 11.4v at the dash (even after full charge) but shows 12.4 at the battery terminals. It has only been in for 8 months or so, but that was due to a battery dying Agent P styles.

[crash277]

not that this is really usefull, but i think the pop pop of the Vtwin is one of my favorite things when i pull up next to a guy on a harley LoL. the look on their face when they see a super sport is usually pretty funny.

how do the spark plugs look? i was getting a misfire on my 04 600rrr found a fouled plug. swapped them all out, and the bike sorted itself out, i pulled the plugs after a track day to see if there was a reason it stopped working properly, but all 4 looked the exact same.

[MASHMAN]

Hey crash... I put new plugs in, not that the old ones were done, but just in case and it hasn't made a diff. The Prila used to pop pop quite happily and as ya say it is a lervely sound, but this is different and new and way too much popping for my liking as well as the threat of stall and the "misfiring"... something just isn't quite right.

[crash277]

the popping noise is fuel burning in the exhaust, are there any mods done to the bike? IE exhaust, non OEM air filter?

[Cajun]

Hey Neil... not too bad here, just want the Prila sorted . All nice and lovely up norf?

Last service was 6 months ago... Air filter is clean, I've changed the plugs, stator looks fine (whew). Am starting to wonder if another battery has bitten the dust although I have a Motobatt in and it only reads 11.4v at the dash (even after full charge) but shows 12.4 at the battery terminals. It has only been in for 8 months or so, but that was due to a battery dying Agent P styles.

live across the ditch now mate. brought both bikes across with us

[MASHMAN]

the popping noise is fuel burning in the exhaust, are there any mods done to the bike? IE exhaust, non OEM air filter?

I wish it were that easy . Nah, just one day she started with the extra popping

live across the ditch now mate. brought both bikes across with us

Splitter... how's the straight roads and sun treating ya?

[03rsvMille]

I bet that you have an exhaust leak... oxygen is making it into the exhaust pipe probably from some fitting someplace. I had the same issue with a Daytona 955i that I used to have. Your exhaust is hot and there is unused fuel being blown through there, the only thing that is needed for that to ignite is oxygen.

After I went through the exhaust and discovered and fixed a loose fitting, the problem stopped.

Also be sure to inspect your welds and the can itself.

[BB1000]

throttle bodies may need a sync .... worst case it could be ya stator about to burn up .... one of the signs on mine when it burn out was extra pop pop pop

[theknurl]

Gordon;
air leak, check all the high quality vacuum lines

also the intake manifolds have wrench clearance slots molded in...... i know for an Allen wrench
if you tighten the clamps the manifold pulls away from the TB

all 4 of mine were leaking......popping alot too .....just fill the slots with RTV silicone, let it harden and clamp it up again

[shelbyguy]

I bet that you have an exhaust leak... oxygen is making it into the exhaust pipe probably from some fitting someplace. I had the same issue with a Daytona 955i that I used to have. Your exhaust is hot and there is unused fuel being blown through there, the only thing that is needed for that to ignite is oxygen.

After I went through the exhaust and discovered and fixed a loose fitting, the problem stopped.

Also be sure to inspect your welds and the can itself.

this?

[MASHMAN]

Thanks for the help so far. I did get a couple of little turns on the rear exhaust manifold (pissing down so no test yet) and there is what looks like a drip of oil suspended from one of the bolts off the rear cylinder but I'm not 100% where that's coming from. The black tube that connects the rear cylinder to the airbox, any ideas why it would be "wet" with fuel/oil? I'm wondering if while riding the liquid is coming out of the afore mentioned pipe and is running around the back of the rear cylinder and leaving a drip once stopped.

[SoulDaddy]

I have the same stuff happening, plus some backfiring through the top when letting off the gas to shift. Hunting, rangey revs below 4,500. Changed plugs, tried another chip, filter's clean, etc. Did find a cracked vac line off of the fuel regulator which helped a bit.

Will try the RTV in the boots, another synch of the bods and maybe it's time to check the valves, too. Suspecting plug wires, too.

Looking for a cliff.

[mcjongs]

Check the vacuum lines to the PPC, the check vale in that line, black and white...and could it be the membrane in the clutch?

Btw, the PPC is prone to failure of the plastic vacuum valve, especially on early bikes with a red valve (and in rarer instances failure of the rubber diaphragm). I wouldn't count on it too much...

Source; http://www.apriliaforum.com/forums/s...-down-shifting

(The PPC is a simple vacuum-actuated mechanical device whose only purpose is to slightly ease wheel lock on hard downshifts.
Works with vacuum on full engine deceleration over a membrane in the clutch that slightly reduces the clutch spring loads... I'm not sure mine is working as I somtimes experience rear tire lock if I'm to quick on releasing the clutc on hard braking/downshifts....But I've learned to regulate this by using two fingers on the clutch...)