Took my bike for a walk tonight

S

Superior77

'77xs650
Messages
50
Reaction score
0
Points
6
Location
Superior, WI
Changed the oil and cleaned the filter on my newest '77. Ran it to check for leaks. No leaks and runs fairly well. So I thought I would take it for a ride. Made it 3 blocks and it died. Electrical problem, yes. Walked it home and checked the battery, seems good. With a little research I went to check the main fuse. Pulled the cover and it looks like a new inline fuse holder has been wired in. Pulled the fuse and yes it's blown. Now here's the question. Everything I understand about the main fuse on a '77 is that it is 20amps. The one I pulled out is a 30amp fuse. Why? Should I put a 20amp back in it? I wonder if the 30amp was placed in it because of popping 20s or just the PO not knowing. Is it a bad thing to run 30amps. I will pick up some of each tomorrow.
 
I forgot to say that I had washed it 4 days ago and this would be the first ride since then. Did I just get something wet? How will I know? What should I do next?
 
Get out the multimeter and start chasing wires for shorts. Yes, 20 amp fuses is the max for mains. 10A for everything else. I doubt the wash did anything. Look for burned wire. 30 amps is quite a bit.
 
I'm not sure where it's been posted but the fuses are sized to obviously protect devices but another large reason is to protect the actual wiring harness. Too large of a fuses allows a power draw larger than the wires in the harness can withstand. This results in burned up wires and a headache to chase down and rewire.

So it's a good thing you found the 30A so you can replace it with a 20A.
 
I won't be able to do much until this weekend. I'll put in a 20amp fuse and see what happens. I will also trace a few wires and see if any are burnt. Maybe just a bad fuse or could be something bigger. Time will tell. The walk home wasn't that bad. It could have been worse. I'm just glad I don't live on top of a hill.
 
Never wash a bike without riding it as soon as you are finished. Water tends to get into the nooks and crannies and not evaporate unless the engine gets hot and wind blows the water away.

I talked to a guy that told a story how he had his Triumph engine rebuilt and the next spring his engine was locked. I asked if he washed his bike before he put it away? "Yes." Did you ride it after? "No, just pushed it into the garage."

Write a short paragraph diagnosising what happened. (Just kidding :^)

Tom Graham
 
Sup, this happened to me with my '73. In my case, ever since I replaced the (missing) grommets in the headlight bucket where the harness goes through, I have never been able to replicate the problem. So, look for a short, and it might be a good idea to check around your bucket and head tube area, where the harness/wires are subject to rubbing. Try to replicate the problem at home.

TC
 
Superior77 said:
It could have been worse. I'm just glad I don't live on top of a hill.
Click to expand...

Been there done date. And I live at the top of a hill.

One time I was riding with my GF and my bike died. Pulled the cover off, found the main fuse blown. Looked in the ditch and riped the foil out of a discarded pack of smokes. Jumped the fuse with the foil and we road home. My GF was totally amazed! "OMG I'm dating MacGyver!"
 
Quick update: I just got home from work and put a 20amp fuse in. Turned the key and the lights all work as well as the horn. Hit the starter button and the fuse fried. I guess I'll start chasing wires.
 
And check those grommets. Move the bars around and look for chafing, particularly in areas where the wires/harness have to move to accommodate steering.

TC
 
I just took the ohm meter to the rectifier. There was no reading when I was on the red to the whites. Do local Yamaha dealers carry these?
 
I gave the wires a quick inspection and didn't find any obvious problems. Would a bad rectifier blow the main fuse? Should I be checking something more?
 
It's more them the rectifier. I took the one off my other '77 and mounted on this one. It still blew the fuse. I will keep searching. Any suggestions on where to start?
 

Similar threads

N
Odd charging problems on '75 xs650
Replies
8
Views
217
Its been a long time
I
motormike
DIASATER!
Replies
17
Views
1K
motormike
motormike
lumbee
AVMCP (another VM carb post)
Replies
11
Views
295
Bruno_c
B
bosco659
Bike is sick today....
Replies
18
Views
1K
bosco659
bosco659
M
Leaks and stuck RPM (high) even with clutch in. 83' xs650 Heritage Special
3 4 5
Replies
86
Views
11K
5twins
5twins
Back
Top