Thunderace electrical gremlin

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 12:02 pm

I've had the bike nearly 3 years so it's older than that. Yes the gen wire was broken. I've just fitted a basic on off switch from the circuit near to the temp sensor. The fan also can still come on automatically.

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 3:23 pm

Started the bike took neg battery terminal off runs fine with side lights, indicators, horn and brake lights, put either fan or headlights on it cuts even at higher revs than idle. Failing alternator???

yo4hgx · Post by **yo4hgx** » Mon Apr 18, 2016 3:42 pm

Do not run the engine with the battery disconnected, you may damage the TCI (ignition/processor unit).

Engine running fine on battery only is a good enough indication of a failing alternator/rectifier/regulator. Most probably one of the AC coils is fried or grounded, you could check it by the continuity meaning as described before (service manual pag. 8-27/28) or measure the 3 phases voltage between the three wires by pairs 1-2, 2-3, 1-3, should be anywhere in the 80V/AC area. If that's alright, the problem is within the rectifier/regulator that is a bit harder to check.

I for one would look for a good condition generator unit, at least for testing.

Hope that helped.

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 3:50 pm

Thanks, I only ran It very briefly and won't be doing again. I'll check the AC coils, I can mostly rule out rec/reg as I believe it's in with the stator and the rpm dip problem was there with the old engine too. I'm gona plumb for a tired gen not being able to keep up. Again thanks for the advice guys.

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 4:20 pm

Hold on, am i being dumb here? Are the stator, gen/alt, rec/reg all in the same thing???? Told you i was colourblind and avoid electrics!!!!!

Teego · Post by **Teego** » Mon Apr 18, 2016 5:17 pm

wonkiwheel wrote:Thanks, I only ran It very briefly and won't be doing again. I'll check the AC coils, I can mostly rule out rec/reg as I believe it's in with the stator and the rpm dip problem was there with the old engine too. I'm gona plumb for a tired gen not being able to keep up. Again thanks for the advice guys.

Hmmmmmmmm.
If the problem was there with the old engine and the new one it points to something that's not part of the engine. Unless both engines suffered from the same problem - unlikely.
So IMHO its not the generator.
Good luck though. Electrics can be a pain.

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 5:37 pm

The gen was used on the old engine too, so it could possibly be it. I've just done a resistance test and the rotor arm is just within spec, the brushes look ok but the stator coil measured 0.5 across the three terminals as opposed to spec 0.19-0.21, so I'm guessing is lts buggered!!!!

Teego · Post by **Teego** » Mon Apr 18, 2016 5:39 pm

wonkiwheel wrote:The gen was used on the old engine too, so it could possibly be it. I've just done a resistance test and the rotor arm is just within spec, the brushes look ok but the stator coil measured 0.5 across the three terminals as opposed to spec 0.19-0.21, so I'm guessing is lts buggered!!!!

Good point. You'll be down to the breakers then.

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 5:44 pm

As soon as I'm back from Benidorm I'd say that's where ull find me. Having looked at removing it, it seems I have to take the water pump off to get it out...... Smashin.....!!!

yo4hgx · Post by **yo4hgx** » Mon Apr 18, 2016 7:31 pm

wonkiwheel wrote:Hold on, am i being dumb here? Are the stator, gen/alt, rec/reg all in the same thing???? Told you i was colourblind and avoid electrics!!!!!

Yes, unlike the newer bikes the exups have the generator "car style", meaning that both, rotor AND stator are winded, using the exciting as charging control. All in one unit...

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 7:44 pm

Thanks for your help guys, after testing the gen ( the rotor was in actual fact out of spec, was 3.1 instead of 3.05) im just going to get a good used one and fingers crossed solves the gremlin.

Post by **Stig** » Mon Apr 18, 2016 7:51 pm

My lad does stator rewinding as part of his job. Wonder if they can be redone.

oldskoolexup · Post by **oldskoolexup** » Mon Apr 18, 2016 7:54 pm

wonkiwheel wrote:......... it seems I have to take the water pump off to get it out......!!!

Easier than the ridiculously "engineered" starter clutch that lives in the bowels of the crankcase next to the gearbox!!!!!!

Sounds like you have a result though or at least a good place to start.

You should be able to get a working alternator to test theory.

Enjoy Benidorm.......

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 7:56 pm

i have a friend who has his own winding firm, im sure they can be, ill have a chat with him see how much of a hole in my pocket he would make!!!!

wonkiwheel · Post by **wonkiwheel** » Mon Apr 18, 2016 8:11 pm

Starter clutch........The sound of it fills me with dread!!!!!! Yea not too bad really, its just wet!!!!! Thanks again, if i remember going to beni ill let you know how it was....stag do and all that!!!!!!