is this bike a XJ? if so some help please

Hi trying to help my retired neighbor with a motorcycle he got on a trade. First off someone has painted it, so I'm not sure if its a xj. Here is some info I got off it. The tag on the steering stem says 5/81 JYA4HOO BA119273 under the left side cover it says engine family BYA065044A6 displacement 653cc. It does not turn over, the battery is junk,there is rust in the tank,its been sitting for 5 years after it quit running. Any help is appreciated. Here is what I have done for starters. Hooked battery charger to battery leads. Neutral light comes on but it does not turn over. Hooked charger to starter turns over and has 120 lbs compression on all cylinders but no spark. I have never dabbled in motorcycle repairs but have with Honda 3 wheelers. My experience with them were that you could unplug the on off switch wires and they would have spark if the switch was bad. So I took out the headlight and unplugged the connector to the switch still no help.(may not do anything for this just thought i would try) next suggestion?thanks

 

CDI ignition systems are powered by a magneto. They are turned off by shorting the system to ground. That's why you can disconnect the switch to make them run.

TCI ignition systems (which the XJ has) are powered by the battery. They are turned off by removing the power supply (via the key). So unplugging the key switch shuts them down.

I don't have your other answers here at work. I'm sure someone will be along shortly to help decode your VIN.

 

http://www.xjbikes.com/Forums/viewtopic/t=14577.html

That will give you an answer to what you've got if it's an XJ.

Those compression numbers seem a bit low.

How many miles? Pictures of the beast?

Where you located? Someone here might be up the road to lend a hand.

 

thanks for the quick replys. I searched and read the excellent post about ignition troubleshooting and tci's by SQLGuy. As far as unplugging the handlebar run/off switch. Your saying that does nothing? I think you thought I meant the key switch. Anyhow, the hadlebar run/off switch feels funky and the starter button is missing too. I have no wiring diagrams so if someone can help in that area I appreciate it. Then I will check the switch at the connector i disconnected. With the rust in the tank, I am sure the carbs are just as bad. But I figured I would start with basics. IE compression and spark. Mileage is 26131. After reviewing the ignition t/sing post I figured the red/white wires must go to the off/run switch. I checked continuity at these wires and the switch is working. So I plugged it back in and checked power at the red/white wire + black wire of the TCI. I have 11 volts until I stick a screwdriver into the broken starter button(the spring is still there and if I push on the spring with the screwdriver it cranks) Then the voltage drops to 5-6 volts. Bad starter drawing too much current?

 

How old is that battery? If it's more than 2-3 years old, I would be suspicious. If it still won't crank after replacing the battery with a known good one, then I'd look at the starter or the starter relay. In my experience a fresh battery can make a world of difference. BTW that does look like an XJ.

 

yes a fresh battery is good. I don't have my wiring diagram in front of me but I think that you have power going through the off/run/off switch and by unplugging that you do not complete the circuit and the ignition won't spark.

 

Find your xj wiring diagram here. http://xjdiagrams.thundervalleypower.com/

If the engine is cranking but the battery voltage falls much below about 10-11 volts the TCI ignition wont work and you wont get a spark.

A word of caution - dont try to jump start from a running car - this has been known to damage the TCI ignition.

If it has been stood the carbs and tank will definately need attention but you have come to the right place for help!!

 

Thank you very much everyone. This forum is impressing me. I am also having fun. I appreciate the wiring diagram links! I had to go to work, so I will Chase wires and connections tomorrow morning. As far as batteries go the one in the bike is completly dead and dried up. Plus its the wrong one and the polarity is backwards!! Nothing like working on something after someone else has f'ed it up. I am only useing a battery charger as my power supply during this troubleshooting. Is this a no no?

 

Using a battery charger might work, but you could also get some other-than-expected results that could end up being misleading.

You gave us some incomplete or bad info in regard to the VIN; there is a "shorty VIN" on the top of the transmission housing right above the clutch cover. It will be a three-digit "model identifier" (ie; 4U8) followed by the "serial" part of the serial number. That will positively identify it. From the pics, it looks like a non-YICS motor, which would make it an early Maxim or a 650 Seca. From the dual discs, I'm thinking 650 Seca, unless other parts-swappage has occurred. A good possibility, since those look like Maxim bars on there. I suspect a "bitsa." (Bitsa this, bitsa that.)

 

That sure looks like a 650 Maxim front caliper and I don't see a disc on the right. It's also got maxim mufflers (painted black). Looks like Maxim gauges too.

Bet its an 81 650 Maxim (XJ650H).

 

Yes I think I left out the 8th and 9th digit of the vin. I was getting this number from the decal on the left side of the steering stem. I think a cable wore it off. I read the hyperlink on how to decode the vin. My brain is still spinning. But I will look for numbers stamped on the rightside tomorrow.

 

If it's been pieced together....

The Shorty VIN on the motor will tell you what bike the motor is from.

On the steering stem, on the opposite side from the factory sticker (right side), the short VIN will be STAMPED into the frame.

If the numbers match, it's the original engine. If not, it's had a heart transplant.

We've had other members on here discover after some searching that they had a different size motor than what they thought.

Useful info if you need to replace parts as not all parts fit all models.

 

the full vin is JYA4H7009BA119273 the short vin on bike and engine is 4H7-119273 so it is a 81 XJ650H. Here is where I am at in the troubleshooting. I have 11-12 volts at the red/white wires both at the solenoid connection and the TCI. When the starter engages it drops to 4-5 volts and the starter barely turns. However when I put the battery charger hot lead on the starter wire it spins over like crazy. Is the solenoid bad and drawing all the power? Also when I look at the wire diagram and check the red/white wire from the solenoid connection. Its open from there to the ignition coils connection and TCI connection? From what I read the 81 has none of the side stand safety crap. The fuses are fine. Am I missing something. What should I check now?

 

I'd start right there.

Fully charge the battery (at 1.5v rate) and take it to the auto to have it load tested. Easiest thing to check, and very well could be something just that simple.

 

The battery is completely dead, im only useing a battery charger for power supply.

 

I would get a good battery in there, or boost from a car battery.

 

+1

 

Apparently the charger has enough capacity to crank the bike when hooked directly to the starter, so it shouldn't be the issue.

Starter relay would fry fuses if it was drawing too much power. It's not your problem.

You've got a poor connection somewhere.

Start by connecting the (-) battery lead to the (-) charger lead then touch your charger (+) to the starter lug. If it cranks you know your ground is good. If it doesn't crank then you know you likely have a problem where the (-) battery cable attaches to the frame.

If that was all good you probably have a poor connection where the (+) battery lead attaches to the solenoid - or just aren't getting a good connection from the charger to the battery cable.

 

I have cleaned the leads at the battery and solenoid. I have the charger hooked right to the leads where they connect to the battery. Everytime you hit the start button same result, major voltage drop and starter barely tries to spin. But when I move the positive lead of the charger to the bottom lead on the solenoid(the direct wire to the starter )she spins like a mo-fo. What about the open I am getting on the red/white wire at the solenoid connector to the coils and tci ? This bike doesn't have the side stand relay but does it have the starter circuit cut-out relay shown in the wire diagram ? Where is that if so?