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No Electrics but will start, or did..

Posted: Sun Aug 23, 2020 4:11 pm
by philrob1966
Hi guys.
I just bought a 1993 GPZ500 and am having some problems.

The main thing is that the bike will not start from the button and there appears to be no power to anything electrical at all.
If I short out the starter relay with the ignition key in the correct position, the engine turns over and did start but now refuses, it's very low on fuel and been stood for a long time I think. Last MOT was 2004..
Any advice would be greatly appreciated.

Re: No Electrics but will start, or did..

Posted: Sun Aug 23, 2020 5:02 pm
by philrob1966
philrob1966 wrote:
Sun Aug 23, 2020 4:11 pm
Hi guys.
I just bought a 1993 GPZ500 and am having some problems.

The main thing is that the bike will not start from the button and there appears to be no power to anything electrical at all.
If I short out the starter relay with the ignition key in the correct position, the engine turns over and did start but now refuses, it's been stood for a long time I think. Last MOT was 2004..
Any advice would be greatly appreciated.

Re: No Electrics but will start, or did..

Posted: Sun Aug 23, 2020 8:44 pm
by yanw
The Haynes manual has a wiring diagram. A cheap multimeter, cleaning connections as you go will let you logically find what is working and what is not.

Re: No Electrics but will start, or did..

Posted: Mon Aug 24, 2020 12:17 am
by philrob1966
Thanks for the advice but nothing is working at all. The only sign of life is when I short the starter relay and the engine turns over. I'm really quite clueless with these things but do own a multi meter. I'm guessing that there must be power from the battery as the engine turns over.
Also, i've noticed rust inside the fuel tank, will it be ok to rinse out the tank with petrol and fit a fuel filter or will I need a new tank ? I don't really want to change it if I don't need as the paintwork is in good condition.

Re: No Electrics but will start, or did..

Posted: Mon Aug 24, 2020 4:11 pm
by chpz
Can't offer much more advice than Yanw on the electrical side, except to put a new battery in it. If its been stood for a long time there's a good chance the battery could be knackered too. Get some contact cleaner and wet & dry paper then go through the wiring loom from one end to the other, cleaning one terminal at a time. Just had to do it myself and it worked wonders!

Regarding the fuel tank, I'm going through the exact same thing at the moment. Do not run the bike for any extended period with dirty fuel. Bits of rust will clog the carbs and you'll forever be taking them out to clean. I recommend taking the carbs out for a good long clean anyway if the bike has been stood, but once you've done that, if you want to run the bike hook a funnel up to the fuel pipe and pour fuel in there, not from the tank. I would look into getting the tank cleaned and lined.

Re: No Electrics but will start, or did..

Posted: Mon Aug 24, 2020 7:42 pm
by yanw
With the wiring manual and a multimeter you can start at the battery, check there is voltage and then look for the connection to the ignition. The diagram should have the wire colours on it. Unplug the connector, clean the terminals and check there is "continuity" between the ends of the loom for that wire. Next look at the positions of the ignition switch and check that you get "continuity" at the different key positions. You just need to follow the diagram starting from the battery and check it works.

As for the tank empty the fuel into a car, soak it with pickling viniger from Wilko, rinse it with distiled water and then rinse a little bit of diesel round to stop it flash rusting. Fit a fuel filter and be prepared that when the eletrics are sorted you will probably need to strip the carbs ;).

Re: No Electrics but will start, or did..

Posted: Tue Aug 25, 2020 10:35 pm
by philrob1966
Thanks guys, I've removed the battery and it's now charging and seems ok. Tomorrow I'm going to remove the fuel tank and do like you suggest with vinegar.
I've sprayed the ignition barrel with a good amount of electrical circuit cleaner and when I refit the battery I'll try to test if the wires have any power near the switch and clean any contacts that I come across.
I'll write here how I get on.

Re: No Electrics but will start, or did..

Posted: Thu Aug 27, 2020 1:29 pm
by philrob1966
Well, I didn't get to the electrics as when I was looking into an oil leak issue I discovered that one of the mounting holes on the engine block (where the generator casing bolts one) has been broken off.. I'm now wondering about the best way to fix this before going any further with the other issues.
does anyone have any experience using JB weld for this type of thing ? Any repair will need to be threaded and have the outer casing bolted to it. Its the bottom 'Lug' closest to the gear lever.
Again, thanks in advance for any advice.

Re: No Electrics but will start, or did..

Posted: Thu Aug 27, 2020 2:15 pm
by yanw
JB weld is ok. You can make a sort of mold using blutac which stops it flowing around. A better fix would be to Tig and tap it bit with the oil contamination this might be tricky.