Aprilia af1 sport pro help needed

[davis-af1]

hi all was wondering if you could give me some advise with the above mentioned bike.

I have cleaned the carb, replaced the coil and starter motor and spark plug and it still will not run.

Does any one have any ideas why.

Also could you possibly help me in the hunt for a wiring diagram for the bike as it looks as though stevie wonder has had a go at the electrics.

Also does any one think that it could be the CDI unit that has broken down internally.

Sorry to ask for more information but i am new to aprilias and was wondering if it could be the timing that is out, that is of course if the bike is timed.

Thanks in advance for the help.

Dan
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Af1 125 1992 Not running cant figure it out

[Kickstart]

Hi

Are you getting a spark?

The timing could easily be out. You need a dial gauge on these to set the timing properly.

There is no seperate cdi unit, it is built into the coil.

Are you sure you have the right coil? For the later AF1 there are 2 types of stator and 2 types of coil (in addition to the system used on the very early AF1 which used a black coil which had no advance / retard). The later coil will work with both the earlier and later stator, but the early coil will only work with the early stator.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[davis-af1]

hi cheers for the pm containing the diagram and key.

I have a good spark as the spark plug was new yesterday.

At the rear of the bike under the rear passenger seat i have a black box with Ducati electrics written on the front.
Does any body know what this is.

Two of these wires are supposed to link to the voltage rectifier. which only one does.

Also after removing the bolt used for locking top dead center, a mixture of water fuel and 2 stroke oil leaked from the bottom. could this be a problem with it not starting.

Thanks again for all the help i have been working on it now for over a week and it still doesnt want to start/fire, when it does it simply runs for around 30 seconds then dies. if you try to advance the throttle then the bike dies instantly.

cheers
dan
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Af1 125 1992 Not running cant figure it out

[Kickstart]

Hi

Black box you mention is probably the power valve control unit (does it have something like 7800 painted on in white paint?).

The Futura ignition system is very simple. Basically 3 wires from the stator to the oil, and one wire from the coil into the loom (which is only there so you can stop the ignition system from sparking - it is earthed out by the kill switch / ignition switch to stop the engine). It doesn't care about the regulator / rectifier unit, that is purely for the charging system. However with only one wire you are not going to charge the battery (and not sure that the regulator / rectifier won't be damaged by it).

If you have water / fuel / oil coming from there then it has come from somewhere. A tiny amount would be expected if you have been struggling to start it for a while, but more than that isn't normal. Possibly the needle valve in the carb is not sealing and is flooding the engine. However there shouldn't be any water there at all.

Sounds to me though almost like it hasn't got sufficient fuel. Is the fuel filter (in the carb body) clear?

One thing to check is the condition of the reed valves. If these are damaged (and not sealing) then it might well start but die when the throttle was opened.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[davis-af1]

right thanks for the help so far you sure do know your stuff.

The black box has those numbers painted on.

Im starting to think it is a carb problem, do you know the size of the jets used in the carb as i will look to purchase them from my local shop.

Also could it possible be a split or similar in the vacuum pipe from the carburetta?

Many thanks again.

Dan
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Af1 125 1992 Not running cant figure it out

[Kickstart]

Hi

Jets are unlikely to wear (certainly not those involved at around idle speed) so not worth replacing unless you really need to.

Ones I have from a Futura owners handbook (trying to translate from Italian) are 34mm carb, 148 main jet, min jet 36, DP266 atomiser tube, K56 needle on the 3rd position, fuel vale 40, idle screw one turn out, cjhoke jet 60 and float weight 9 grammes.

Ignition timing is 12 degree btdc @10000rpm.

There is no vacuum pipe from the carb. There is the intake mount (ie, carb to barrel) and these can crack and result in a weak mixture. Similarly the main bearing seals can wear and allow air in, resulting in a weak mixture. However in both cases I would expect a high idle speed (although if really bad the mixture would be too weak to run).

Have you checked the fuel filter in the carb?

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[davis-af1]

finally think ive got to the bottom of the problem!!!

After re-checking the spark,fuel flow, and everything else again and again, and several attempts to start with nothing but backfiring and flames from the exhaust!!!!!

I decided to remove the fly wheel and check the timing, thats when i found it. the flywheel had not been tightened sufficiently which was odd to say the least. Then when i finally got it removed i realised the problem

I THINK!!
The woodruff key that locates the flywheel and holds the timing had been destroyed or not replaced before i brought the bike as a non runner.

So just to say .... Thanks for all the help and hopefully it should be on the road again soon

Cheers guys

Dan
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Af1 125 1992 Not running cant figure it out

[Kickstart]

Hi

Sounds like the likely problem. New one should be cheap and easy. Setting the ignition timing is a bit of a pain though (you need a dial gauge, locate TDC and the turn the engine back by the right amount and at that point the small ~1.5mm hole in the flywheel should line up with a tiny cutout in the stator).

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing