Yamaha Virago535 main fuse smoke

[dekip]

Hi to all,

I have Virago 535 from 1993 and suddenly i noticed smoke under seat when i stopped. I removed seat and find out that main fuse which is 30A is too hot that it melt housing a little. Beside, that fuse box former owner has put as a separate one because in original fuse box i can see it was melting, too. An electrician guy change that small fuse box with one, new fuse and new connectors and it was ok few days. Until yesterday...

My question is, what could be the problem? What should i check? Where these wires goes?

The last smoke wasn't from that new box, because what i can see it is ok. My electrician is on vacation, but days are so good to let my Virago in garage.

I can see on the net that there are a lot of main fuse problems, but solutions vary...

[Riejufixing]

[RhynoCZ]

What Riejufixing says.

Clean all the connectors and battery terminals. Also disconnect the reg/rec unit and clean those connectors too. If your electrics are so filthy that it would melt a 30A fuse, the odds are the stator unit is the next one to end up in flames.

You want to remove any cockcheese like substance and anything green must go as well. That is oxidation.

Then check all the wiring for damage. It could be some of the wires are rubbing onto the frame or each other and the isolation on them is long gone, creating a short circuit.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[dekip]

Ok. I just checked some wires. Not too much in details, though. I opened those plastic covers from the sides. On the right side i noticed something a little bit rusty. Could it be an issue? Should i clean it somehow? Not sure what thing is, on the first place.

[dekip]

Here is another one

[Kawasaki Jimbo]

If the 30 amp fuse hasn't blown (and it sounds like it should have) I'd check to see if dirt or corrosion on the fuse connector was allowing current to bypass the fuse. Then I'd suspect a faulty reg/rec. It will make an acrid stink.

[Polarbear]

The first thing I would do is take all that insulation tape off and check if there are any nasty surprises underneath.
____________________
Triumph Trophy Launch Edition

[dekip]

Fuse didn't blow. It is ok. New fuse box that is set few days ago is ok, fuse is ok. Fuse connectors are ok. They are new, btw. Wires under the seat are all ok. I didn't saw any melted place. All i saw is that thing on the pictures. Not sure what it is.

What is reg/rec? Is it that thing on the pictures?

[RhynoCZ]

Reg/Rec = Regulator/Rectifier. It takes whatever 40-60V AC from the alternator (stator) and turns it into roughly 14.5V DC. Not in the picture.

The thing in the picture is the starter solenoid. It's what connects the battery to the starter motor when you press the start button. It's also the most power hungry part on the bike.

By the way, I would disconnect it and clean all that rust.
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[dekip]

Where is that reg/rec, then? What should i look?

[RhynoCZ]

No. 1; part number: 42X-81960-A1-00

https://www.partsdepot.cz/picdily/676460.jpg
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[dekip]

Ok, what i get so far...

First of all, i dismantle almost all, seats, side plastic covers, metal covers... I let it running for a maybe 20 min or so. Not a single hot spot on wires. That single extra fuse box for 30A is warm as the bikes frame, so nothing special. My guess is it is ok.

That reg/rec thing you point me is, well, disconnected!?
I found that it has a new one under the seat which can be seen in photos. Old one was just sitting there for esthetic purposes. After the time bike was running, this reg/rec was little hot, but i could hold my hand on it, so the temperature wasn't high at all.
https://i.imgur.com/sVWPu9j.jpg?1

https://i.imgur.com/jkTUw3P.jpg?2

After a while when engine become a little bit warmer there was that smoke, but...
Smoke showed up somewhere between second cylinder and battery. I checked it and noticed that there is a small oil leakage and it could be that it touch the exhaust pipe that is going out the cylinder. I am not sure, it could be under it from the gear box or so. Smoke just showed up from somewhere there. Somewhere behind that key lock.

https://i.imgur.com/L1i5rEM.jpg?2

https://i.imgur.com/lNGrEGW.jpg?2

I turned off engine while i looked it, and remove that oily drops. After that when i turn engine on again, there was nothing. No smoke.

Could it be the issue and not the wire problem? Someone said there could be stator issue, but where would be its position on the bike so i could check it out?

Thanks in advance.

[someone]

[Easy-X]

Eeek! Been a bit of rewiring done I recognise that copper cable - it's heavy duty speaker wire - I tend to use the same myself for artistic effect on exposed wiring. There's nothing wrong with it as such but it hints that someone just used what happened to be lying about!

If it was me I'd have to replace all the tape with heatshrink wrap
____________________
Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[RhynoCZ]

Looking at that oil leak on the second cylinder head, I would even guess it drips oil onto the exhaust, which then burns away = smoke.

Evaporating water may also seem like smoke. Did the engine get wet before you saw the smoke?
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[dekip]

@someone
@HardlyDavidson
As i said, after a while of running without covers, i didn't noticed anything wrong with wires. Not a single hot spot or joint. But i will do as you suggest and check all those joints insulated by a tape. Beside, i am not sure what cause that melted fuse box which i replaced. The new one is cold as much as bikes frame itself.

@RhynoCZ
I didn't ride it on rain, weather was nice and sunny. My guess after these checks is oil on exhaust. I am not sure from which spot it leaks, i think i will need to remove gas tank if it will do any good. It is not much at all, it looks just a few drops, but it seems enough. Any suggestion what to check, or some good images of cylinder head. It looks like that gasket of valve cover is leaking or that chrome pipe. It is hard to see.

Where is alternator on this bike? Starter is under first cylinder, i think.

[RhynoCZ]

If luck is on your side, it'll be the valve cover seal. Remove, clean, maybe replace, reassemble.

If it's the head or even the cylinder, well, then might get a bit more complicated.

Alternator/stator; fiddle with that only if your charging system is dead.

But, as you have come here for some answers, here it is...

*left hand side, round engine cover, right where the crank is.

https://www.partsdepot.cz/picdily/676431.jpg
____________________
'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[dekip]

Man, where you get all those images? They are awesome.
____________________
Long time reviewer in computer magazine.
That include all wireless devices, SBC and microcontrollers. When my brain get stuck, all that helps is ride.
My bikes: MZ 175SE (1967), Yamaha Virago XV535 (1993) and TVS Apache (2008)

[WD Forte]

https://www.partsdepot.cz
____________________
bikers smell of wee

[RhynoCZ]

[dekip]

It's ok. Czech language is pretty similar to my language. Thank you again.

It was heavy rain here, so i will take a ride tomorrow to focus on eventual smoke while riding. Then i will try to see anyhow where that leakage is coming from. That valve cap is my first pick.

I am pretty much happy there is no wiring problem. You could imagine my face when i saw smoke and after removing seat saw that melted fuse box.
____________________
Long time reviewer in computer magazine.
That include all wireless devices, SBC and microcontrollers. When my brain get stuck, all that helps is ride.
My bikes: MZ 175SE (1967), Yamaha Virago XV535 (1993) and TVS Apache (2008)

[Kawasaki Jimbo]

[dekip]