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roearn

Joined:

Apr 10

Posts: 23

roearn says:

Aprilia Misfire

I have a 2004 RSV Factory. Twice in the last few weeks I have had a misfire happen after about 60 miles riding. If I keep riding the misfire gets worse. If I stop for a few minutes the engine fires up with no misfire but starts misfiring after a couple of miles. Fortunately I have been able to get home after stopping and starting a number of times.   The bike has been checked at an Aprilia dealer and no electrical faults were logged in the bike computer. The throttle bodies were balanced and fuel mixture set. The fuel tank was emptied and refilled with fuel and a stabiliser added. No noticeable water was found in the fuel. The rectifier was changed about 2000 miles ago after a "burn out" of the connector between the alternator and rectifier. A multimeter shows 13.8 volts across the battery. Any opinions on what might be happening.

Regards,

Roearn:winkie::winkie:

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  • Posted 257 days ago (03 August 2013 11:23)

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fogie

Joined:

Jan 04

Posts: 730

fogie says:

13.8v

Personally I would be a bit wary of only 13.8volts with the engine running...... would much prefer a little over 14volts. Doesn't sound much, but will make a difference over a rideout. Could be a fault in the charging system/wiring, or a battery that needs attention. Could you hook up a car type (dial) voltmeter to the battery, and go for a run, and see how the charging system/battery behaves? even a "sealed" battery can, and needs, to be topped up with water. Most people never try, and by the time the battery stops playing ball, it's buggered. Have a try anyway, nought to lose.  :smile

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kcmc

Joined:

Jan 08

Posts: 6559

kcmc says:

Aprilia RSV Factory,

Hi Roearn

Must say it does still sound like an electrical fault?but to eliminate a possible mechanical problem for peace of mind it could be worth checking the valve clearances,could have a tight one in there?just a thought.Good Luck

KCMC:tongue:

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norris

Joined:

Nov 02

Posts: 1309

norris says:

RSV

When you say a 'burn out' between the alternator and rectifier, do you mean the brown connector that joins them at the side of the fairing panel?
Mine started misfiring which turned out to be that brown connector becoming brittle with the heat, it eventually shorted out the alternator when it cracked.
The misfire sounds like the same symptons I was getting and could be your alternator on the way out. Common fault. Ask on RSVRNET as there's a lot of info and knowledgeable people on there.

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roearn

Joined:

Apr 10

Posts: 23

roearn says:

Aprilia Misfire

Thanks Fogie, I was wondering about the 13.8 volts, and it had occurred to me it would be nice to see how the charging was going whilst riding. Your comment has pushed me to looking at rigging a voltmeter across the battery.

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roearn

Joined:

Apr 10

Posts: 23

roearn says:

Aprilia Misfire

Hi Norris, Yes it was the brown connector and it had completely melted away. I rewired from the alternator to a new Rectifier with soldered joints. I have checked again the voltage output from the alternator and it is reading 75 volts and above on each of the 3 phases and the stator coil resistance is 0.5ohms. These are what they should be.

Thanks :smile

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roearn

Joined:

Apr 10

Posts: 23

roearn says:

Aprilia Misfire

Hi kcmc, I tend to think its electrical, having had the fuel checked. I shall pursue the electrics but shall bear in mind what you say about a tight valve.

Thanks  

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domster

Joined:

Sep 12

Posts: 190

domster says:

Misfire

Check the plug caps aren't breaking down when hot, making a ticking noise or arcing.

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