Magazine test: Performance Bikes October 1991 - Nine 125's tested, AF1 Futura

 

my bike: new old stock parts

 I have started to collect up some parts for my AF1 rebuild.

Firstly a replacement coolent reservoir tank as the original had a hole in it, see here . My top tip is to search for an item like this via the part number, some Aprilia parts are used on multiple bikes and as such the prices vary depending on the rarity of the bike, rather than the part. I have seen this part on ebay from £6.99 to around £45...

Next I have manged to collect up some new bodywork over the past few months for when I do the final cosmetic push. I will need a decal kit for the fairing but also for the tank and seat unit if I end up painting there.

Magazine; Aprilia shower, Practice Sportsbike July 2016

 

Magazine; 125 miles by 125, Practice Sportsbike December 2013

 

stuff that's wrong so far...

I haven't had much AF1 time recently as the MBX80 took priority getting it ready for the Stafford Classic Bike Show, you can read about that here.

Back to the Aprilia, after the carburation woes I took it on a shake down ride to see what was going on, I picked up on the following. 1/ the front bake definitely needs bleeding as it was a bit hit and miss on lever travel. 2/ I am pretty convinced the power valve is stuck open, low down is actually bad but is super flat in the mid range with a strong top end rush. 3/ when warm the tick over is to low and stalls.

I pulled the bike apart to see if I could work out what was going on with the power valve. The solenoid was pulled well out the housing meaning it wasn't operating at all and the cable was under tension as well holding the valve open, basically it needs a new cable as the cable fitted isn't the right one. Interestingly I have a spare solenoid in my spares box I got with the bike so i think this problem has been on the bike for a little while un-diagnosed?

According to the manual the solenoid should sit at rest between 7.5mm and 8.5mm out, when it activates it pulls the piston in, pulling the cable and thus opening the powervalve.

NEXT DAY EDIT: 

I changed the cable this morning and checked all functions including the power valve itself. When started the solenoid now actives opening the PV (the manual calls this a self cleaning process), when revving over 2500rpm the solenoid releases closing the PV. A test ride is needed to see if it opens again over 7800rpm, but I am fairly happy this is now working.

the solenoid is as far in as I could get it here, the cable is restricting movement.

I noticed there is a hole in the coolant expansion tank, meaning the system can't pressurise. Thankfully this tank was used on loads of aprilia's so is readily available new. part number AP8101910

holey smoke batman

I found a random plug, anybody know what it is meant for????

what the???

Lastly there are loads of fairing clips missing and the fuel hose was made of cheese. It also has an intermittent rear brake like fault which was fixed by just cleaning the terminals. No doubt there will be more minor issues, but once I am happy mechanically I will then turn to some more fun stuff and make some cosmetic improvements.

Carburettor specifications - all AF1 models

 Carburettor standard specifications - all models Dell'Orto 

My bike - carb issues part 2, fixed

Following on from part 1 of my carb/ running issues I have now re-built the carb to exact Aprilia specifications. For good measure I replaced the spark plug which is a NGK BR10EG and I also had to replace the battery as mine was dead and wouldn't except a charge, I bought a Motobatt 12N5.5-3B from Busters.

With everything back together the bike fired in to life, ran sweetly and most importantly the carb didn't over flow which points to the float weight all along.

Now that I am happy that bike is running correctly I can move on to some more restoration type jobs.