Won't pull away from rest, but then runs if kicked

[The Pookster]

During a wet run yesterday my B4 with LRP X12 and Sphere TC stopped on track. Now it won't pull away from rest but if you give it a kick it runs OK until next time it comes to rest, then same thing happens.

Swapped the sensor lead and stripped and cleaned the motor but still the same. The speedo LEDs come on as expected but the motor doesn't turn.

Speedo seems dry, haven't got a different speedo or motor to try.

Any ideas?

[gazbaz2]

Originally Posted by The Pookster

During a wet run yesterday my B4 with LRP X12 and Sphere TC stopped on track. Now it won't pull away from rest but if you give it a kick it runs OK until next time it comes to rest, then same thing happens.

Swapped the sensor lead and stripped and cleaned the motor but still the same. The speedo LEDs come on as expected but the motor doesn't turn.

Speedo seems dry, haven't got a different speedo or motor to try.

Any ideas?

Sounds like the sensor in the motor its self matey, i had 1 like that, get it sent off they'll replace it no probs

[jim76]

could be moisture in the sensor etc. Stick it in an airing cupboard for a day or two to dry out properly and give it another try

[The Pookster]

Well it's all dry.

The motor makes no attempt to turn, if you hold the throttle on after 3 seconds the red and amber lights flash alternately on the speedo but can't find out what this fault code means.

[Smartalec]

Mine did exactly the same, sent speedo back to SMD and they replaced it

[barry]

I'm having the same problem. I went to the track today for a practise and managed to short circuit the wiring for about a second. Never done that before, and certainly won't do it again.

So I corrected the battery connector and plugged in and switched on. As soon as I switched the switch, smoke started appearing from around the esc area. I decided to come home to sort it out.

After testing it home, it appears to have developed a severe case of cogging. I haven't run this set up before, so not sure if my wiring blunder has anything to do with it or not... At first it was just a bit rough - it would appear to take about half a second to decide which way to spin the motor. I've read lowering the gearing helps, but it won't turn without a pinion!

I have a sphere tc esc and nosram storm evolution 10.5 motor and also get the red and orange lights if a hold full throttle for a few seconds.

Any help gratefully received. I don't know whether it's the motor or esc.

Cheers,
Barry

[sparrow.2]

Check the speedo with a new capacitor in place. It might have not liked being exposed to reversed polarity and blown. Inspect it and check to see if it has bulged a little. If the top is domed or the sides aren't straight it's gone.

Your symptom sounds a lot like my LRP speedos when the cap has gone. Don't try and run it without the capacitor or it will blow up the speedo.

[barry]

Thanks for the tip - I guess it's worth a try. The smoke could have been coming from the capacitor I guess.

Don't suppose you know of a stockist, or part no. etc?

Trust this to happen days before the season's first round :-(

Cheers,
Barry

Originally Posted by sparrow.2

Check the speedo with a new capacitor in place. It might have not liked being exposed to reversed polarity and blown. Inspect it and check to see if it has bulged a little. If the top is domed or the sides aren't straight it's gone.

Your symptom sounds a lot like my LRP speedos when the cap has gone. Don't try and run it without the capacitor or it will blow up the speedo.

[The Pookster]

Checked my capacitor and it has not bulged.

But giving the speedo a sniff it smells a bit burnt...

[Big G]

sensor fault on the speedo is my guess. I had the same with my SP speedo. a weird pop fizzle when I connected it. Does the car run with the sensor disconnected?

try another motor and with the sensor disconnected, but I would say it was the speedo at fault.

[rc_dan]

deleted

[barry]

Now you mention it, this set up has always popped when connecting the battery even when the switch was in the off position.

The motor does not move at all with the sensor cable disconnected.

Barry

Originally Posted by Big G

sensor fault on the speedo is my guess. I had the same with my SP speedo. a weird pop fizzle when I connected it. Does the car run with the sensor disconnected?

try another motor and with the sensor disconnected, but I would say it was the speedo at fault.

[barry]

Yep, mine smells too!

Barry

Originally Posted by The Pookster

Checked my capacitor and it has not bulged.

But giving the speedo a sniff it smells a bit burnt...

[The Pookster]

New speedo = fixed.

How much is it to get an LRP speedo repaired...?

[simoncrabb]

They can't always be repaired, depends what's broken.

I have a pile of broken ones here, and they're irreparable as the tracks on the circuit board have lifted when the FETs have smoked...

Brushless speedos sure are delicate, they're almost consumables these days!

[barry]

I contacted smd today, the lrp distributer. They don't repair them, but will do a 'goodwill' price on replacements or upgrades. The replacement price was around £120. Most expensive 1 second mistake I ever made. They also gave me the number of an independent repairer, so I might give him a ring.

Barry

Originally Posted by The Pookster

New speedo = fixed.

How much is it to get an LRP speedo repaired...?

[Devastator]

When I had pretty much all these exact problems, first I had the speedo replaced which fixed it, then not long after I got the same problem and this time it was the motor.

Both times got it all replaced for free, I went through mirage racing which as far as I was aware is the UK distributor of LRP/Nosram.