Please help with a 1992 Fireblade!

[J20a]

My boyfriend owns a 1992 900 Fireblade and it's kind of gone to crap in the matter of days. Bike is very well kept. His pride and joy. Cleans it every few days.

It all started back in July.. on the way down to Donington. The electrics fuse blew. Since then until about 3 weeks ago it had blown about 3 more times. It had never happened before.

Then on the way to Knott End Bike Meet one night the bike shut down. A few lads also riding to the same area stopped.. had a look at the bike, said it was a flat battery. And that it should be taken home asap to charge. The gave him a bump start and the bike was working fine. Only without the lights. The bike had worked completely fine as long as he didn't have his lights on.

Then 2 days ago he was out and about on the bike apparently the bike just died. No warning at all. Fuse just popped. So he just figured it was the same problem he had, had previously. Sorted it out. Changed the fuse, again.

All the time the bike has been owned it has been using a 15amp electrics fuse. So that's what he had always been putting in when it blew. He noticed as he was changing it that the fuse cap said that it was 30amp he needed. So he changed it to a 30 and as soon as the bike started.. it melted the wires.

Not sure if that's exactly what happened. But it's the gist. From what i've heard from the story every time he's told it to someone to get advice is the fuse kept blowing. He changed it to what he thought it needed all this time and the wire melted.

Yesterday he went out and bought a brand new battery and it still isn't working.

One of our mates who knows electrics and has worked on cars and bikes said that it is probably a short somewhere. Possibly something to do with the earth wire. He said that since everything else is working, only that one main switch fuse is bust, that will be the problem.

Any ideas? Please help whereever possible! And also any suggestions on how much it will cost, approximately, to get sorted!

Thanks a lot!!
____________________
? Steph ?
I r mechanic student, rawr !
"Drink 'till she's cute, but stop before the wedding"

[Guest]

[finpos]

I agree, sounds like what you have there is an intermittant short through something. It will be an utter pain in the bum to find. as mentioned, wiring around where the headstock will be the prime candidate.

Here's a trick that might help you find it. Get a 12V bulb (eg an indicator bulb ) and attach a couple of wires to it. Solder them on or use tape or an old bulb holder if you've got one. In fact an old indicator stalk is ideal. connect it to 12v, make sure it comes on.

now take your new bulb tool and connect it to the two terminals that normally hold the fuse, i.e. use. your bulb instead of the fuse. turn all the lights etc on the bike off, but leave the ignition on. is the bulb lit? if it is, that means the current from the battery is flowing to earth through the bulb and the elusive short. start tugging and pulling, twisting and disconnecting anything in sight. when the bulb goes out, you've found the short.

note the bulb is doing a similar job to the fuse, but it's limiting the current from the battery instead of blowing. if you switch on any other lights e.g. brake light ,it will only come on dimly because of your bulb tool.

the one problem/clue you have is that you say that it works fine when the lights are off - which indicates there's a short to earth somewhere between the light switch and one of the bulbs. To help you track this down, take out all the light bulbs (taillight, headlight etc), turn ON all the switches on the bike and repeat the above.

hope you find it.

fin.

[stu_m]

its the rectifier

[iCraig]

I second Stu in this, Honda Rectifiers aren't that strong, the fact its lasted 13 years is good going.

The rectifier is probably overchargeing the battery so therefore its been killed and no longer holding a charge.

Have a look at davidsilverspares.co.uk for a replacement rectifier.

[Claud 14.7 to 1]

I also suspect the regulator/rectifier. Sounds very similar to when my reg/rec went.

If you want to be sure before you buy a new one, get hold of a Haynes and a mulitmeter and test the reg/rec, charging system and wiring as well.

[J20a]

Thanks for the replies guys!

Will pass on the info and hopegully he'll find it. He'll be gutted if he doesn't. Bike has never had any problems in it's life until now
____________________
? Steph ?
I r mechanic student, rawr !
"Drink 'till she's cute, but stop before the wedding"