Yamaha Bruin 350

[rmundell]

Soon to begin working on a 2002 (i believe) Bruin 350 i recently got back. Reportedly will shut-off while driving it, and blows a fuse (i have not gotten a battery, and begun diagnosis myself yet).

Was told if they change fuse and it goes again for a while until it happens again.

Figured it was worth asking here if anyone has had a similar experience, and determined the cause (worth a shot right?)? TIA. 

[Mech]

Sounds like a wire with bad/worn insulation. First thing I'd do would be to wriggle all the wires bit by bit with the engine running to see where the short might be, then I'd inspect the wiring for worn insulation.

Up around where the wires move when the steering moves is a common place for a lot of bikes.

[rmundell]

Thanks, where i plan to start after doing a visual inspection. Just figured id ask in case there is a common issue with something i am not aware of that others are. 

[Gwbarm]

I would also check the regulator/ rectifier for proper operation.

[rmundell]

Thank you, any common issue or aware of an issue with this model in particular?

[Gwbarm]

None that I know of

[rmundell]

Ok, thank you for the reply. Wishful thinking on my part, but figured it was worth posting the question!

[rmundell]

Ok, have battery in and got fuse replaced and running, was just getting it to idle and determine what other things i need to do (clean carburetor etc.) and it popped the ignition fuse after about 5 minutes idling. 

Once dead, the ignition switch was completely dead. Can anyone share an electrical Schematic with me please? This way i can start tracing circuits related to this fuse.

 

TIA, Robert.

[Ajmboy]

2 hours ago, rmundell said:

Can anyone share an electrical Schematic with me please?

There are a couple of service manuals in the downloads section:

 

[Gwbarm]

I think i would start with the voltage regulator they are fairly cheap.

[Mech]

Could just disconnect the regulator and see if it stops the problem...

[rmundell]

Exactly what im planning to disconnect items on the circuit to trace where problem is, just wanted to view schematic to verify what is all on that fused circuit. Dont have enough posts yet to download, so didnt know if anyone could share one.

 

[Mech]

I'd wriggle all the wires as a first step. If it is a chafed insulation and you disturb it and move it so it's not touching anymore it can be the real mongrel thing trying to find it after that and you end up with an ongoing and intermittent problem. If it's a faulty component it will always be faulty.. plenty of time to find that.

[rmundell]

Ok all here is the update, and apparently the fix on my Bruin 350.

Had the electrical issue of fuse popping, but quad wouldnt idle without choke, so knew main jet was gunked up. 

Took top tank cover and tank off to get to carb to remove to clean for further diag/testing on fuse popping once it would idle on its own. 

On this quad there is a rubber (heat shield i am guessing) under the fuel tank zip tied to the frame, and apparently someone had done the same thing to get to carb to clean previously, and failed to zip tie the harness back up along with the heat shield! So it had fallen onto the exhaust heat shield and melted through the tape and rubber insulation into the red/blk  ignition feed wire going to the idiot lights!! Where it had fallen down and melted was hidden by the fuel tank cover plastic so not visible until all removed.

 

So thanks everyone for the input, Found problem, repaired, cleaned carb, and zip tied harness back up as it should be, and made successful test ride with no issues! 

Hope this insight may assist someone else in the future with a similar issue!

[Mech]

Onya !

It's a hassle but when we have a suspected short in the wiring in these quads we really do need to take all the bodywork off and inspect all the wiring. Far too many people start throwing stators, regulators, cdi, switches.. everything and anything, at the bike rather than do the foot work.

Electronic components these days are very reliable. If an electronic part does fail, It's likely as not to have failed because of a wiring problem..