More Motorcycle Problems for the Boy

As I am sure I've mentioned before, my son -- who is not actually still a boy -- purchased for himself a used motorcycle some time ago. It was a good starter bike, a 2007 Yamaha V-Star 650 Classic. However, he bought it from a guy who'd wrecked it and done only cosmetic repairs, and had left it sitting outside in all weather for many months. It looked great, in other words, but it has a lot of problems. 

In a way that's also a good 'starter' experience, as you learn most about motorcycle maintenance by doing motorcycle maintenance. Today's problem is an electrical problem, which are the worst in terms of diagnosis. I asked my buddy who builds electrical motorcycles to have a look at the wiring diagram while I pulled everything apart with my son and we traced connections and tested them with a multi-meter.

In the end my friend and I came to the same conclusion independently, which is that it was probably the starter solenoid. That's weird, because I just replaced it last summer to address another one of the many problems this bike has had. However, it's a cheap part and an easy swap ("easy" after disassembling the whole bike to test various electrical connections and relays). It's also a part that fails commonly because it takes a lot more current than any other relay on the bike -- the only real drain on the battery is when the starter circuit dumps current through the solenoid to the starter motor in order to turn the engine over until it starts. After that the bike generates enough electricity through normal operation to recharge the battery and operate all the other electrical systems.

Hopefully another new solenoid will fix the issue.

6 comments:

raven said...

If that does not work, check the starter cable under the shrink wrap at the end. - sometimes they fatigue crack at the lug if they have been soldered-copper hardens under heat..
And the grounds- old bikes are famous for bad grounds.

Grim said...

I did in fact check both of those. In fact, the ground was my first thought.

raven said...

If the new solenoid solves the problem (I assume it is a no crank, no start issue), it might be illuminating to take the old ones apart and see if they both had the same failure mode.

We have a Honeywell control on our boiler and it would fail when we had big power surges.
I finally took the old units apart
They were failing at the same point- the leads of a resistor were sweated into a printed circuit board- magnified, it would look like a piece of 1" rod stood on end on a piece of tinfoil-and the joint would burn through. A daub of solder increased the area enough to prevent it from reoccurring- so far, anyway.


Mike Guenther said...

Do you want another project bike to work on? My late brother has/had a 1976 Honda GL 1000 Goldwing. It has been sitting outside for some time. Other than the seat and warped plexiglass on the removable windscreen, it doesn't look too bad. But I'm not expert. It's also in your neck of the woods.

Mike Guenther said...

Also, it could be had cheap. I just have to apply for a lost title.

Grim said...

Thank you but no. 1976 was a good year for motorcycling, but not necessarily for motorcycles. I’ve got all the projects I can handle.