AP81129275 | Moto-Abruzzo

I honestly couldn’t believe my luck ….. dozens of perfectly normal starts after the one stuck-solenoid moment during our 10 days away and then, this morning in the comfort of the old barn, first start of the day it stuck again!

So it was off with the seats, top deck and right hand plastics, disconnect the battery Earth (Ground) then snip a few tie-wraps, unclip the two-pin connector and twiddle the 10mm spanner to undo the battery/starter cables from the old solenoid and voila! One dodgy 50A and 14 year old solenoid confined to the bin …… by way of stripping, measuring and knocking up in CAD!

It’s pretty obvious from the picture that one side of the contacts has been burnt and welded together such that the return spring couldn’t provide enough force to pry it apart again – that was the job of a swift whack from the all-powerful 1/2″ ratchet!

The new solenoid (AP81129275) was bench tested and shows a coil resistance of 4.4Ω pulling 2.9A at 12.8V – approximately! Now 2.9A is quite a current draw in itself, especially when you take into account the amount of wiring (under specified?) and switches/diodes along the way. The only way the solenoid really has of reducing pitting/burning is by opening and closing as fast as possible – opening is purely by return spring but the closing speed is proportional to the applied Volts/Amps ……. and if this is low then the solenoid will become sluggish and more susceptible to damage. So tomorrows little job will be to look at losses through the entire circuit up to the solenoid. In fact looking at the circuit diagram and simulating it in ‘EveryCircuit’ (Android app) it seems that the best possible current flow path you can give the solenoid is – bike in neutral, side-stand up AND pull in the clutch before hitting the starter … this adds a mighty 0.1V over ‘neutral only’. In comparison bypassing the diode block completely could elicit another 0.55V at a struggle!

Aprilia Caponord ETV1000 Rally-Raid Yuasa YTX14H-BS battery With a hot brew to the left and a warm mouse to the right, I’m ready to reflect on the last ten days as the Capo sits outside soaking up the morning Abruzzo sun. After the hiccup at 138 miles the remainder of the 3,000 miles went perfectly, not one low-volt drama in sight. Mind you, that is with a new YTX14H-BS battery in the bike since last Thursday!

That same morning she’d sailed through her MOT with a clean sheet at 120,861 miles and now reads 122,135 miles at journeys end. Waiting in the panniers is a new Aprilia 150A starter solenoid (AP81129275) ordered online from Aprilia performance (UK) and deliver in 48Hrs which is great service, also a beautifully made power/ground cable kit from John Walker who pulled out the stops to make sure the kit reached me before we departed for Europe. More on this later.

So on reflection, what next for the dear old Capo? Well I’ll install the solenoid and cables over the next week or so and dig out the rear wheel/sprocket carrier bearings and seals, since a dull drone can be heard from the back wheel at about 50-70mph – and is getting steadily louder. There’s no play or sign of rust near the seal, but my guess is that one of the bearings is on the way out, so best do a touch of pre-emptive maintenance I think. 😀

Highs and lows of the trip …… low, the DVSA. I can’t and don’t want to say anything on that front …… the high, yesterday afternoon, slicing through the late afternoon A14 traffic side by side with a new gen Caponord also two-up. We kept each other company for 20 minutes or so until he peeled off for Rimini, big smiles and waves all round! Great fun!!

And so, waffle over, without further adoo let the spanner twiddling begin! 😯

Tag: AP81129275

Dodgy solenoid hmmmm?

And now the dust settles …..