90 XT EAC Starting troubles
 

After letting the bike sit for approx two weeks it was running fine. Occasionally the bike has a hard time getting going in the cold mornings so I need to jump it in order to not kill the battery dead trying to get to to start. However, not it seems I have busted the bike. My problem:

Whenever the battery is hooked up it sparks, and the starter cranks over and over again, even with the key out of the ignition, or with the key in the off position. I don't know what to do and the yamaha manual isn't much help as I only have a shitty voltmeter and don't understand electronic diagrams all that well. There is a wire running from the negative terminal of the battery, and it is cooked, the insulation has melted. The battery also all but boiled dry just cranking over and over again when I was trying to get the bike to die.

What I have done:

Replaced the battery
Cheked started regulator and it is working.

Any help or suggestions before I take it to the shop?

Thanks!

James

change the burned piece of wire if you can...

From your description, either a major short circuit somewhere, or a faulty ignition switch. I'd start by checking the wiring out. No need for any expertise - just dismantle enough to see every inch of every wire from front to back of the bike, and concentrating on wiring around and above the engine. If you can see any naked wires touching or shorting to the frame, there's your problem. It's a cheap and easy solution before you go throwing money at a mechanic.

And yes, replace the damaged wire. It's been subjected to a load it was never designed for.

Stop, it usually is real simple.

I'll bet it's the starter relay that has gone stuck. Sometimes you can just knok on it with a screwdriver and it will breake free. Mine did, and some buddys did as well. Do it while the battery is disconnected. Recharge your're battery, and you shold be game again.

Mine has worked fine after that.

I saw a guy on a forum having the same problem on his yamaha R1, so its okay that it happens for our "cheap" bikes i guess =)

Good luck.


With that said, how cold is "cold" for you?

The bike shoukld start fine even in cold weather, how thick is your're oil? try look for false air intake and such. My XT starts fine in -10 degrees celsius. (5W40 fullsynthetic oil)

Something sound wrong when its so hard to start, that you drain the battery. Start with checking the color of the sparkplug.



Cheers.

Starter Relay!!
 

Hi,

What you describe happened to me 3 times already, I had a weak battery because I left the hot grip overnight, and even after recharging the battery it never fully recovered the starter relay was going and going...

I would simply change the starter relay and make sure the battery is fully charged before thinking starting the bike again

I am going to have to replace the starter relay becuase I have done everything else and it just doesn't seem to be working. I have to replace the wiring still and then possibly replace the battery as well. I am contemplating just ordering a new wiring loom and doing the whole thing becuase a lot of my connections are very old or broken and are limping along. I will also replace the sparkplug once I get everything ripped out!

Anyone know where I can order a wiring loom/starter relay to OEM without destroying my wallet? this is stateside as well FYI.

Thanks for all of the replies!

Don't buy a new relay yet! I agree with Jens. Disconnect the old relay. Clean up the connectors and give it a few firm taps with a screwdriver. The relay is just a switch. It's either on or off, yours is stuck on which is why your bikes trying to start even without a key in the ignition. A tap may well free it off. It often does.

I think you probably cooked your wiring and battery when you jumped it from the car.

so I should definitely order a new wiring harness. I only ask becuase some of the plastic connectors are very worn and broken, so I might as well start replacing it now when the bike is all ripped apart.

Spark plug is definitely a go too then?

Ok when I was searching again for any burnt up wiring i found out the the Ignition coil assembly and the spark plug cap had a bunch of corrosion in their connection, which might be another cause for bad spark? looking at the schematics i am not even sure if they are supposed to come apart, so any information would be helpful!

Tapping the relay did the trick, but now I still have no spark so it must be something on the spark plug end. I don't have a nice enough voltmeter to test the spark plug cap and don't have a deep socket to remove the spark plug, which I hope is the problem. I will be running to the auto parts store tomorrow to buy a socket and a new plug to try that! Thanks for all the replies so far!

If you remove the plug cap from thr HT lead (should just unscrew) you should see the wire core of the HT lead if not just cut a couple of mm of lead hold the lead so the core is a couple of mm from the engine and check for a spark when engine is turned over.
The plug caps do fail and are cheap enough so maybe get a spare and a new plug you may need the one day, To remove the plug I use a deep 18mm socket 3/8 drive and an extension.

Thanks for all of the replies, turns out the plug wasn't in the best condition, it was covered in like black soot, PLUS the connection between the cap and the wire going into it was filled with a copper-patina colored crust. cleaned it out, replaced the plug and my baby runs again! Now my only problem is that it seems starved, starts, but dies after sputtering for 20-30 seconds and seems to die waiting for stoplights, so I might have to search the forums for some answers!

once again thanks for all of the help!

James