I'm assuming the voltage is incorrect so the motor is being burnt out, I have a voltage reader arriving tomorrow to confirm if this is the cause.
full bike check
- Thread starter HairyHarry
- Start date
Both terminals measure at 11.20 volts. I'm stumped, something is seizing the fans within such a short amount of time
Joined May 2011
90 Posts | 0+
It's true, in the case of electric motors, that the lower the applied voltage, the higher the current drawn. But, even with 11.2v (which is suspiciously low - should be 13-ish) that would not cause the motor to fail. The fan units are (in IMHO) pretty cheap and crappy - but, even so. What does send the drawn current skywards is any form of additional load on the fan - either by physical friction (blades hitting the housing, for example), or drag in the motor bearings - the shaft runs in sintered bushes that release, or should release, lubricant as required - wouldn't hurt to try a drop of light oil. I'd be running a prolonged bench test on the fans before refitting to the bike. The one fan I had fail on me had overheated to the point that the motor housing had melted - I assume because of dry bearings, but I can't prove that. Going back to the 11.2v - how old is your battery?
I haven't checked the battery, I only picked the bike up 2 weeks ago but I'll see tomorrow. I think I've found the cause of the seizing fan on your suggestion on the physical friction overloading the fan, as the fan itself is not the issue as I had replaced it, so I had a closer inspection of the radiator and it's left hand side top section is slightly bent downwards, how does that happen? can only think it must have been in an accident. I'll switch my only working fan onto the left and rotate it to see if there's any friction tomorrow but I'm 90% sure that's the problem. Another thing to replace
Hard to tell without having a freely spinning fan to test it but the bracket the fan sits onto was a few mm out, so the fan must have been slightly in contact with the radiator. I've forced the bracket out further and hopefully the new fan arrives Tuesday. That should be it, much cheaper than replacing the whole radiator, despite it being bent I don't have the funds to just keep replacing things on this bike anymore.
Joined May 2011
90 Posts | 0+
Blimey! Bent radiator sounds like a drop . . . look on the bright side though - it doesn't leak . . . or does it? You mentioned that the previous owner had run it dry? Ordinarily, coolant levels do not drop. Keep an eye on the level! Do whatever you have to do to ensure the LH fan spins freely - then all should be well.
Battery - On any vehicle, especially high compression big twins, the battery is the life and soul of the party. I've fitted a Motobatt (AGM - big CCA) to mine - you have to modify the retaining clamp a bit - but the difference is amazing.
As I said before, once sorted, they're great bikes - and, once again, make sure you see Griff . . .
Battery - On any vehicle, especially high compression big twins, the battery is the life and soul of the party. I've fitted a Motobatt (AGM - big CCA) to mine - you have to modify the retaining clamp a bit - but the difference is amazing.
As I said before, once sorted, they're great bikes - and, once again, make sure you see Griff . . .
It doesn't appear to leak, the damage doesn't seem to be too bad either. The prior owner just stuck to the service schedule and did nothing himself inbetween, so he was running it dry with only 1 fan working. It's booked in with Aprilia peformance but not until late next month. I wonder what brilliant problem I will find next week. I'll get that Motobatt on order, thanks for the suggestion
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Well that's the fan sorted, still running well after a long ride. I'm not attaching both sides of the fan to the radiator, this allows clearance for the fan to run. I'll replace the radiator some other time!
So next on the list is the slipping clutch. Hopefully that will be fixed tomorrow with an oil change, also I'm putting that Motobatt battery in :thumbup
So next on the list is the slipping clutch. Hopefully that will be fixed tomorrow with an oil change, also I'm putting that Motobatt battery in :thumbup
Joined May 2011
90 Posts | 0+
Here's how I did it. The spacer measures 100 x 20 x 10mm. The bolts are M5x30. The clamp presses forwards as the bolts tighten. My first attempt was a much deeper spacer and longer bolts to allow the clamp to sit 'properly' on the top edge of the battery, but, because of the angle of the captive bolts, that didn't work - (the clamp moves away from the battery). You could of course design a completely new clamp - but this works fine for me! Apologies for the photographic quality!
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Brilliant, if it works for you I'll do the same for my battery. Thanks especially for the bolt/spacer dimensions
I picked mine up for £49.95, AGM batteries can be left dormant for longer without having to trickle charge, and have a higher crank than a standard battery
Well the oil change made a HUGE difference to the bike. Clutch isn't slipping, performance is tons better ( Castrol 10w40 )
The front shudders slightly with harsh braking, probably a slightly warped disc..?
The front shudders slightly with harsh braking, probably a slightly warped disc..?
Joined Oct 2009
195 Posts | 0+
Hertfordshire
I believe my replaced battery was on it's way out so I can't compare it with an old battery
More likely to be seized bobbins on the brake carriers, they sometimes sieze and you get same feeling as warped disc. Try cleaning them off with brake cleaner and make sure they all rotate freely, hopefully that will cure it. :thumbup
Hopefully an easy fix then, thanks for your help alwaduk. Bikes nearly back to how it should be
You were right, a few bobbins were seized :thumbup learning quite a lot of things in such a short amount of time on this bike
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