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!
Just found out that the the Capo didn’t want to start in gear with the clutch pulled in …. so suspected a bad clutch switch. In the end it wasn’t, but I’d pulled the old one and did some homework anyway. The switch is a Saia Burgess V4NCS with an actuator kit on top (QA4). Now a direct replacement seems hard to find, however the V4NS as sold by RS-Components is almost the same and comes with 500mm wires already attached, it even has the same 2.5N operating force.
So for a miserly sum of £7.80 (plus VAT & shipping) a new switch can be clipped into the existing actuator shell and spliced into the old loom – simply cut off the yellow wire (not needed) and sheath/splice the other two. A darn sight less than the £70 plus that I’ve seen on the web for an Aprilia item! The only down-side appears to be that the cables exit from the side not the rear ….. no biggie really.
On the other hand if your switch has a bad actuator, then just buy that alone for a whopping £3.24 (plus VAT and shipping). In fact I’m sure that a bit more digging would throw up these items for considerably less …… I just got bored!
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! 😯
It was a little after 1.30 in the morning, warm but foggy. I’d just had a hot drink and bite to eat while reflecting on the 138 miles covered and 1,200 yet to cover. The Capo was running fine but my eyes were already beginning to sting from riding with the visor up because of the fog – hopefully that would clear by the time I hit Switzerland.
So I saddled up and hit the starter ……. In an instant the early morning optimism bubble burst. The starter rolled over, then stalled. The dashboard went dark and as I turned the ignition key off I realised the starter was still trying to turn the motor over. Suddenly it began spinning the motor rapidly, so I turned the ignition back on and the motor fired up and the dashboard lit up like normal. but the battery charging was only showing 12.2V because the solenoid was stuck and still powering the starter motor. As quick as possible it was off with the seats (handy having the spare key in my jacket!) then whack the starter solenoid with a 1/2″ ratchet – and the voltage jumped back up to 14V as the solenoid released.
Now the dilemma …… carry on, turn around and head home or wave the plastic card of defeat and get recovered. In for a penny in for a pound as they say …. soldier on! Today I’m typing this up in warm and pleasant Oxford reflecting on the choice I made. As it turned out a good call, the Capo never missed a beat or hesitated once when starting for the rest of the journey. Fixed? Of course not, maybe that was a warning of things to come, so today a 150A starter solenoid has been ordered along with a replacement YTX14-HBS battery.
My thought is that the stuck solenoid was a symptom not the cause …… the question is, why did the battery voltage fall through the floor as soon as a load was placed on it. Thinking it through, if it were a short at the starter then a huge amount of power would have been grounded and yes the solenoid contacts could weld, however I’d expect the battery to get hot and that didn’t happen. So that leaves the possibility of an internal problem with the battery …. maybe a year of bouncing over a dirt and stone road has caused a crack to develop between plates. All I know is I don’t have confidence in it or the solenoid anymore so out they go!
As well as these two new parts I’ve also bit the bullet and ordered a new set of power/ground cables from John Walker in the UK and figure the old girl could well do with a spruce up of the wiring.
Meanwhile on with the show! 😀