My XJ is turning off after 5min

I'm in need of some help. My XJ turns off after 5min. I noticed the battery is drained after those 5min. After charging it, I can use it to turn the bike on again for 5 more min. Just before shutting off I hear a couple of blowbacks from the exhaust, is this normal?

I appreciate any help.

 

You might want to provide in your signature what year and size of your XJ. It helps others to help you. Also what items of maintenance, repair, replacement of parts and items have you done to your bike. Your situation, as you have described, could be many different things and knowing what you have already done to it will help the XJ wizards help you to figure out what is wrong with your bike. Hope this helps..

 

like bruce said. give us some more info. but id check the battery with a multimeter while revving the bike to see if its getting a charge. usually a fully charged battery should last longer than 5 minutes. i had an old xs with a bad alternator that would last about 15 minutes on a full charge.

 

Sorry about that, the bike is an 83 XJ turned bobber. Previous owner made all mods. I have not been able to determine if it's a 650 or 750 maxim. I will add some pics to original post so you can see the bike.

I checked the battery and yes it is being charged. Idle charges it up to 12.8 and when I rev it it can go up to 13.1
I have timed it and when it hits the 5 min mark then it stops charging, once the battery drops to 12.2 the bike shuts off.

 

It's not being charged.

Proper alternator output should give you 14.5 ~ 14.7 volts at the battery, above 2200 rpm.

Start with an inspection of the alternator brushes as well as the wiring associated with the regulator/rectifier (the heat-sink finned component with the large wiring connector coming off it.)

As for determining what the bike is, the is a "shorty" VIN consisting of the model prefix and serial number stamped in the top of your transmission case just above the clutch. The first three digits (4H7, 5G2, etc.,) will tell you what the bike is. See: http://xjbikes.com/Forums/viewtopic/t=14577.html The displacement is also cast onto the front of the cylinder block, with "CC's" expressed as "CM3."

You are going to need a service manual.

 

Right side of frame says 15R-002529
Engine says: 5v2-003751

So is this an 81 frame with a swapped 81 jx650 seca engine?

 

Actually 15R is a 1982 xj750 maxim and 5V2 is a 1982 xj650 seca. So it's a 82 maxim 750 frame with a 82 650 seca engine if I'm not mistaken.

 

It sure does appear to be the case.

Unless the motor itself has been "Frankensteined."

Does the valve cover have "YICS" or just "Yamaha" cast into it? If it's not a YICS motor, then it's a 650 motor alright. From a Seca apparently. (Which makes it an '82, the only model year for the 650 Seca in the States.)

About that service manual: go with the Haynes; it covers "all models" of the 650 and 750. (Just be aware of the errors.)

 

The Valve cover only says Yamaha

 

There you have it. Alternator/charging circuit functionality will be the same. As pointed out above, the readings you're seeing are low, indicating some sort of problem there.

 

Thanks everyone for the help, now that i know exacly what I have on my bike. I have done some of the stuff you have recommended but have had no success.

The last thing I did was get myself a new Rectifier but now the bike wont start (not with the new, not with the old). The engine turns but it wont start. I get a clap from the engine, some smoke out the exhaust, and some fuel out the #4 carb

 

14.5-14-7 seems a little high.

Typical motorcycle battery charge range is 13.8 -14.4. Higher than 14.4 and yer over charging the battery.

below 13.8 and you aren't charging.

The fact that it dies after only 5 minutes and the battery is dead by then tells me that not only are you not charging...there is a heavy draw somewhere.

Start by testing the stator output. I'm sure there is a post somewhere on this forum on how to test it. if it tests out ok start eliminating circuits by disconnecting any aftermarket lights. Then one by one disconnect factory lighting until the voltage starts coming up again.

these are only suggestions and not offered as expert information.

 

14.5 +/- 0.3 volts are what both the service manual, and Clymer call for.

Get a manual, test everything in the charging system. It turns but won't start because there isn't enough juice to fire the coils while the starter is spinning, which is also why it pops once you let go of the starter - with the starter off, the plugs have the juice to fire.

How old is that battery? How are the electrolyte levels?

 

Should have mentioned, that's 14.5 while above 2200rpm. Static, full charge is about 12.8 IIRC.