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Txt Cooling Fan Motor Replacement


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  • 2 months later...

Just had to do mine!

The graupner speed 500 e motor works a treat, good find meldrew.

The supplier sent mine accross the channel in 2 days.

My old motor failed because water had got in wich in turn had corroded the armature and it's array of gobbins. As the rear of the motor is sealed by the rubber boot (of a fashion, water can still get in) I guess water had either got in via the motor mount screws, the forward shaft bearing housing (which does have an o ring seal ) or tracking directly down the wires to the motor.

To help cure this when I mounted the motor into the housing I put a 0.5mm rubber gasket between the motor and casing. I also disassembled the fan wire connector and sealed the terminals / wire with adhesive coated shrink sleeve.

Finally I drilled a 1/8th hole on the bottom of the ally motor mount that the rubber boot sits on, where the hole was I cut away a small piece of the rubber boot then reapplied a small piece of rubber over te hole effectively making it a one way valve so water can get out but cannot get in. Sorry I don't have any pics so I hope the description is clear enough to visualise.

Cheers meldrew :)

Edited by tankygsy
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  • 2 months later...

Girlfriend's 06 Gas Gas 280 fan isn't working (which resulted in milky oil, here we go again).

I really don't know much about the electrical system on these things but so far I've eliminated:

bad connection (tested and bypassed)

dead motor (spins up both ways when connected to a battery)

bad thermostat (works)

Could be that the DC Converter/Rectifier is bad and not putting out enough juice (although some)? How would I test further and what else could the problem be? Reading below, I need to make sure that 12vAC is even getting to the rectifier, also pull off the flywheel to see nothing's funky in there....and then? Don't want to buy a new rectifier blindly...

I found this for reference:




Also, what besides water pump would go out to let coolant into the case?



Edited by stonezone
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  • 2 weeks later...

Yeh the motor and blade are separate from the housing but the motor housing has 3 mounting points which are part of the motor and the motor looks to me like a sealed unit so I can't see me being able to replace just the motor, I'll ring GG UK to see how much a new one is tomorrow.

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  • 5 months later...

It's fairly easy to do, just a couple of things to remember:

on assembly you only get one attempt at fitting the fan blade, it's a press fit and once it's on to get it off you have to destroy the motor - so make sure it's fitted properly and that you have INSTALLED the oring which is fitted between the motor and the motor casing. This oring stop water entering the front of the motor.

Every so often I give the motor a squirt of wd, this helps to remove any moisture that accumulates in the windings.

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Well my suspicions were confirmed today about my fan drawing too much power and running slow....


On a brighter side of things though so far so good...


Only problem ive encountered (well not a problem as such but) is instead of knocking the bottom out of the motor it actually stripped the 2 little screws insted! Which is no great biggy dont get me wrong just a pain trying to find 2 that small lol. I even lifted the 2 metal tabs that secure the motor backplate too but it still knocked the screws out!

Oh well should be here tomorrow.... Mission on!

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  • 2 weeks later...

Yep, cheers for that how to, have just replaced my fan motor with the Graupner Speed 500E, from the online shop of Cornwall Model Boats (quick and helpful), pretty easy and straight forwards to do and only £11.76 inc p&p as opposed to £85 odd for an OEM fan assy!

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  • 4 months later...

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