1981 Yamaha XJ650 battery

I Pulled the acid battery from my good 1981 xj650 to temporarily use on my exact same model 1981 xj650 project bike. After cleaning the carbs and re-installing them, I hooked up my acid battery (from my mint condition xj650 which runs perfectly) to my project bike. On the first try, I was able to get it to crank, but it woukdnt start. I was only able to get it to crank once, then all I would hear is one click sound, and nothing else..my dash lights indication it's in neutral still comes on fine, my brake light and liscense plate light would still turn on, and my blinkers will all work with the key turned on, but when pushing the start button, all I would get is one little click, and nothing else. I hooked the battery up to a trickle charger for about 20 minutes and then tried to start the bike again (with the trickle charger still connected), and the bike fired up and ran and I disconnected from the charger. I even took it for a ride up and down my street several times and went through the gears, then let it sit and idle in my driveway for about 10 minutes and then I shut it off. I wanted to see it would start again on its own, but it would not, it would only give me one click and do nothing again, and all of my lights will still work with the key on, but it will not start. I hooked the battery back up to my trickle charger, and after about a minute I noticed the battery was bubbling on the inside and slightly hissing, I could see it bubbling inside. I immediately disconnected the battery and put it outside. Did i somehow fry the battery? I haven't tried to put it back on my original bike yet to test it and I am afraid to. Anyone have any advice for me? Thanks in advance- Earl

 

dirty starter button dirty battery cables, dirty solinoid connector, clean them.
bad solinoid try jumping across the big nuts on the solinoid see if it will start the bike (make starter turn)
next thing would be your starter may need to be rebuilt

wet acid batterys do that when you charge them, if acid is low refill with DISTILLED water only

 

I will try that tomorrow, the connections in the solenoid are kind of rusty I will sand and clean all connections the best I can. I'm glad I probably didn't harm the battery, I just didn't know they were supposed to bubble like that when charging, so it spooked me. I looked at the levels under light and could see that one of the liquid levels on the battery was at the "max" line, another few at the "min" line, and the other was in between...should I top them all off with distilled water so they are all even at the max line on the battery? , and , if after I've double checked and cleaned all connections tomorrow, ,topped off the battery, and I still get the same problem, do you think I could have a bad stator? The stator is pretty much the bikes alternator, right? I'll let you know what happens tomorrow. Thanks for the reply-Earl

 

^^^^ what xj550h said
Solenoid and starters are rebuildable very common problem on old bikes.

 

yes top off the battery cells that are low with distilled water and recharge

 

Unlikely you have an issue with the stator as the bike runs normally (I assume) once running and starting it seems to be your main issue. Wouldn't hurt to see what the standing voltage of the battery is and what it's drawn down to when pushing the start button

 

I'm such a newbie I still don't have a volt meter , but I will be getting one tomorrow. Quick question, on my bike (1981 Yamaha XJ650), where is the main ground located?? I can't seem To find it anywhere...but I do notice a bolt in the Middle of the engine with nothing on it...is there supposed to be a wire coming from there to my battery's negative terminal? (Sorry for the dumb questions, im still learing)

 

Ground on rear of engine should go to bolt on left side of airbox mount

 

where does the neg terminal wire connect to

 

Pics of what your XJ650 bolt and grounding configuration looks like?

 

Problem solved. Found the ground wire and it does connect to back of Engine on right side. Got a new battery in the mail today, but before installing I cleaned off the connections and took apart and cleaned/sanded all rust off of bolts/washers and connections on the solenoid. put battery in and it started right up hwith half choke. Tweaked the idle screw a bit and got her to idle between 1,000 and 1,500 RPM (with a little less than half choke on). I Took her for a ride around the block a few times, had her up to 4th gear and back down, shifts nice and runs pretty good. I'm pretty stoked that I was able to bring this bike back to life, this was my first project bike first time ever diving into cleaning carbs. I didn't even bench synch the carbs I just left them adjusted the way they were hoping they would already be synched, and I'm thinking maybe the PO synced them at one point , because it looks like he had the carbs off previously and they weren't as dirty as you'd expect for a barn bike. I was told the guy was in the process repairing the bike years ago then never finished it. So maybe he already had the carbs cleaned and synced, then it sat for a few more years until I got my hands on it? Not sure, but it sounds pretty good at idle and when running, maybe I got lucky? Do You think I should still build a DIY sync tool and check it for myself just to be safe? The only thing I did to the carbs aside from cleaning them was I drilled out those brass caps and cleaned then adjusted the mixture screws to 2.5 turns out ( they were originally snug, but I backed each of them out 2.5 turns like everyone told me to. Also: I obviously drained and put brand new oil and oil filter in the bike, (I drained it and let it drip for 3 days before putting in new oil and filter). My oil level is good and I check for leaks every day ( I have none), but looking through the sight glass, I can see the oil has already changed color and isn't really clear anymore, it's a lot darker, more like old oil would look. (I've only had this bike around the block 3 times). Do I need to perform another oil change to really flush out the system? Or am I good? I just want to be safe, I don't want to ruin anything after putting a lot of effort into this bike so far). Thanks again for everything, I really appreciate the replies! You guys are the cats pajamas!

 

A second oil change can't hurt. The oil sitting around shims and buckets doesn't drain so that will turn your oil dark pretty quick

 

]Ok I will change the oil again just to be safe. I'll let you guys know if I run into any problems, but so far so good! PS should I check the valve clearance? Or should I just leave it alone? Like I said it idles runs and drives pretty good. I don't want to open a can of worms if I don't have to. Let me know what you think. My next ordeal with this bike is changing the rear brake pads (rear drum brake), the rear brake doesn't work at all, but I already have the new rear drum brake pads with new springs here, so that's what I'll be diving into next, I hope it's not too difficult. Any tips would be appreciated- thanks again!

 

When it's apart remove the pivot and clean and lube it and polish up the cover while your at it. Oem Yamaha brake shoes are less expensive than many jobber ones like EBC. They are the same shoes that go in the 650 v-star

 

Yes to valve check, yes to second oil change. Valve check is easy as pie, once someone provides you with the link to BigFitz's excellent write up. I would, but hospital drugs (or laziness) prevent me. The oil you put in has heated up and loosened the sludge and sediment that have settled over the years. New filter wouldn't be a bad idea either.

 

Valve adjustment link - big thanks to Dave for getting pics back in it!
http://www.xjbikes.com/forums/threa...ment-with-pics-parts-i-ii.116006/#post-579791

safety is #1, if I understand correctly you are riding around with a disfunctional stopping system (rear brake not working). Think really hard about that statement and ask yourself how important stopping is to you.

Have you even looked to see what is preventing the rear brake from functioning? Something comes loose in there (delamination) and wedges - well now you have a stopping system that is locked up. Hope that doesn't happen at speed.

http://www.xj4ever.com/rear drum brakes.pdf

 

I'm not out cruising around all day with it, like I said just a few test laps around the block for now a few times (residential streets). I wouldn't take this thing out for he day without doing the back brake first. The front brakes are new with bsteel braided brake lines, but you're right, a locking rear wheel could be deadly. I was going to do it yesterday but didn't have time, so hopefully I can get to it today. I guess I might as well order new valve shims and a valve cover gasket now before I even open it up to check the valve clearance? Can I cut my own gasket out of a gasket sheet (the stuff that comes on a roll) or should I order the actual gasket? (For valve cover)

 

Order the valve cover gasket from XJ4EVER.
Do not get shims yet.
Go through the procedure and check what size each shim is in each position (4 intakes/ 4 exhaust) and check the clearances... probably check clearances first and then the shims sizes or which ever....

Now with this information you calculate what clearances need to be adjusted and what size shim needs to replace the existing one. Often times you can do the shim dosey-doh and swap them around and you may find you only need a few instead of all 8.

Now you contact @hogfiddles, as he has a shim pool. Let him know what you need and what you no longer need.

 

Great thanks for the input much appreciated