Greetings!

Hello Everyone,

Well, let me introduce myself. I'm a 24 year old college student majoring in electrical engineering. Yesterday I bought a 1982 Yamaha XJ650 Maxim, and was really excited to drive it home. However the bike died on me a few miles down the road, haha. Needless to say, I had a really crappy day. Hopefully I can get some assistance here in getting it running again. I start school again next week and would dread to take the bus 40+ miles everyday.

I haven't gotten around to do a search on this forum yet for similar problems, but I'll explain what went wrong. Please discontinue reading at this point if you don't want to hear anything that may have been repeated a bunch of times, I don't want to be a nuisance. If the following paragraph is inappropriate please let me know and I'll edit and move it to the correct forum.

Okay, I noticed right away that the RPM was really high. The RPM gauge was past the midpoint most of the time. The bike would die in first gear if I didn't hold down the clutch or take off before the RPM dropped to zero causing the bike to shut off. And while I was riding the bike, it would accelerate on its own without me touching the throttle. Perhaps this was because the RPM was too high? After a couple engine shut offs at red lights, the bike seemed like it took longer and longer for it to gain speed. Also, something in the engine or the engine itself was getting really hot and burning up. It smelled pretty bad.

Eventually the bike seized to accelerate even when working the throttle. And now it doesn't even want to start. The lights don't seem to be dim and the volume of the horn seems to be good as well, so I don't the battery is the problem. After looking around on the internet, I'm going to try a couple things like getting new fuel for it, and taking apart the carburetor and cleaning it. Any help would be greatly appreciated.

Thanks.

 

Sounds like the carbs definitely need to be cleaned.

 

The fuel valve needs to be switched to RES when there still appears to be a lot of fuel in the tank. That might be your problem.

Does sound like you've got some carburetor work to do.

5-6K rpm or more is where you want to be when riding.

 

Welcome to the forums!

Do you know if the bike had been sitting for a long period of time? Daily driver for the previous owner?

Either way, I agree with the others it probably needs the carbs cleaned. It may seem like a daunting task at first but it's very simple with the right tools and information. Plus, when you know how your carbs work it's easier to diagnose any problems that may come up in the future.

Rick's carb cleaning writeup is a must have: http://xjbikes.com/Forums/viewtopic/t=2 ... n+own.html

 

Thanks for the replies.

I don't know how long it was sitting. It was in pretty bad shape, but from my inexperience at the time I couldn't really tell the difference. The jerk that I bought it from doesn't reply to my text or phone calls anymore, so I have no way of knowing.

I tried cleaning my carbs once, and installed, but that didn't work, so I'm going to try cleaning them again. After reading my workshop manual it looks like I might have seized the engine. I'm gonna open it up tomorrow and see if I broke anything. If I did, I may have to part the bike or buy a new engine somehow

 

Also, after reading the manual I saw where the oil window was at, and it was empty. Could I open the engine up and put oil on parts to help lubricate them? Perhaps that's a reason why it won't turn over?

 

YIKES!!! Mayday mayday mayday!!!! An empty oil sight is NOT a good thing. If you have an empty sight, odds are pretty good you've done some damage. You mention the bike won't turn over. By that, do you mean that the starter won't engage or the engine itself is locked?
You need to pull the valve cover and determine if you have damaged any of the cam bearings. You should be able to pull the left side cover and turn the engine over by hand with a wrench. Pull the plugs first to ease this step.
Have you done an oil change on this thing yet? If not, you need to straight away. Then, after you have checked your cams, you should do a compression test and make sure the numbers are good.
Let me check with my wife if I can swing a few hours this weekend. You need to go over that abused thing very carefully so as not to cause any further damage. I've got your number, we'll be in touch.

 

I know it might seem stupidly obvious, but make sure you are checking the oil site when the bike is UPRIGHT, meaning on its center stand or have someone hold it up straight for you. Sometimes people check it with it on it's kick stand and are surprised to see no oil in the glass. Just a helpful suggestion in case you dont know

 

I've already done an oil change, however I didn't do it the way Raven suggested. I have 1 1/2 liters left, so I'll have someone help me with that.

This is what happens when I push the starter button:

I can feel the engine moving underneath me a little bit, but it eventually flutters...(it rumbles). A couple times yesterday, it seemed like it wanted to turn over, but only for a second before it gave up. I charged the battery yesterday at AutoZone, and checked the fuses and spark plugs. The sparks give a spark, but I still haven't replaced them.

 

hi dude,
u say the plugs sparked,did u test them on the bike itself? or some kind of test bed? if u tested them on the bike,its a gd thing coz it means the engine is turning over.
with regards the engine keep reving up,did u check the obv things like making sure the throttle cable is free allowing the throttle to open and close easily? also check yr carb rubbers,especially the ones from the front of carbs to the engine,if any of these allow air in,it will want to keep revving,i had this on mine,it turned out to b the clamps had a slight kink in them,and as i tightened them up it pulled the rubbers into an oval shape and allowed air in.hope some of this may b of help to you.
gd luck with it anyways bud.

 

I tested the sparks while they were on the bike.

I haven't been able to get the bike to turn over since I dismanteled the carburetor (last week). But I also hadn't tested to see if it would accelerate after I brought it home the first day I got it when it cooled down (towed it in my sisters truck). I'm gonna go check it out today and check out what Robert suggested.

 

Maybe its time to check your electrical issues concerning it. Maybe you are not getting enough cranking power? It might be a possibility that something went out and is affecting your current somewhere. Im sure someone here with better knowledge might be able to get you better advise concerning how to go about checking your wiring and such.

Also, not too long ago, I saw a 650 YICS complete running motor sell for $20 on craigslist. When I asked about getting it, it was too late. Too bad, the engine covers alone would have been worth it.

 

From the sounds of it, your battery may be on it's last legs. Get it checked and make sure it is up to the task of turning the motor AND firing the bike.

 

I only got my battery charged the last time, I'll take it in today or tomorrow to see if it's still any good. I've got a multimeter, but I misplaced one of the testing wires, bah!

 

Well I would definitely recommend going through and making sure your battery and such are in good condition before ripping apart the motor.

 

Same thing happened to mine untill my dad bought a new battery. This obv wont fix your running issues but it should help it turn over. Also if your letting the battery sit for a season or a few months put it on a trickle charger to keep it up. Otherwise it will run low and mess with its life.

 

I just got back from taking the battery to AutoZone. They're gonna put it on an eight hour low charge, and they're going to give me the results tomorrow morning.

My uncle checked out my coil, and said that it was no good. He said I wasn't getting any sparks from my plugs, contradicting what that spark plug tester showed last week. I bought new plugs today, and will find out if my battery needs to be thrown out tomorrow.

He also said I wasn't getting any fuel through the carbs, perhaps I screwed something up, but then again, he's an amateur car mechanic.

 

Bring your coils with you when you wander out here Saturday, we'll operationally test them on my Seca. Glad you're getting the battery squared away beforehand. I might just have to wander out there and have a look before too long.

 

Thanks for all your help yesterday, Robert. I greatly appreciate it! I'd also like to thank all those who have posted so far. I'm going to assemble everything on the bike Tuesday. I'll be keeping my fingers crossed!

 

Hopefully thats the problem. Let us know as soon as you find out!

 

Oh before I forget. If you were riding the bike and it died, the battery should have been kept charged by the bikes generator. Unless the battery was that far gone?

 

I was jazzed at the set of carbs Bargomer brought over, they were in BEAUTIFUL shape! A bit of trouble with buggered screws and crud in the fuel feed line but otherwise, a fuel level tweak and they were ready to dial in. I can say that his 2-3 coils were dead (open on the secondary lines) so we pulled a spare set, painted them with liquid electrical tape spray (neat stuff!) to seal the cracks and he was back in business. I expect to hear good news shortly...
Glad to have the chance to meet another forum member, it was a rewarding experience, I highly recommend it!

 

Hmm... Where he be???

 

He be in school, weekend warrior like the rest of us.

 

Sorry about the late response, school has been keeping me busy.

I don't think it could have been the battery that caused the acceleration issue when I first bought it.

However, Robert found that it was my spark plug boots and cables that were causing the engine to not turn over. I'm going to have to verify Thursday or Saturday.

Man, I wish all these quizzes and assignments were next week. I wanna ride already!

 

Does the engine spin when you push the starter button? The coils don't have anything to do with the engine turning over Bargomer, they have to do with ignition which fires the air/fuel mixture. I belive the phrase "not turning over" is a misleading one (confused me to begin with too).
It seems there are more than a few interested parties on this thread Bargomer, hope you are riding soon! Do holler with any questions, we'll see you riding yet!

 

I had the same problem, rig up a fuel test system to make sure your bike is actually getting any gas... mine kept stalling.... all it was is that it wasn't getting any gas haha!!

 

Oh, Man. I hope it's something as simple as that. I'll finally have some daylight hours to work on it today.

 

I assembled everything back on the bike today. I turned the ignition key, and the neutral light came on.

But I tried honking the horn, and I heard a clicking noise...kind of like a static shock. So, I tried honking again and the neutral light went out. So I didn't I turned the ignition off. However, the neutral light went back on when I turned the ignition key again.

I'm gonna study some pics and my manual some more to make sure I'm connecting the electronics the right way.

 

I think I was mistaken. It was the start button that I pressed yesterday when I heard the noise. I'm gonna dissemble the parts and test for any shorts.

 

That still sounds like a dead battery. Did you get a new one?

 

He spilled his battery on the way over to my place this past week. I had some spare electrolyte so we topped off the cells, let it sit for less than an hour and did a load test. While the result was not inspiring, it did hold the current and remain just inside the line for a good test. I recommended he start saving up for another battery.

 

Alright. I'll see about getting a new battery. I'm gonna attempt to check out the shims tomorrow. It looks very intimidating!

 

Any luck sorting out the coils? Found the illustration on page 232 of the Haynes manual. 1-4 on the left side.

 

Yeah, I was able to find it that day. Thanks.

I just got a $30 battery from Wal-Mart. Gonna get it charged in a bit, and I'll check to see if that will resolve the issue.

 

Excellent, don't hesitate to call with questions. I might have some time available this weekend that I can spare to lend a hand. We'll talk.

 

$30? Wow, last time I bought a battery it was over 60. That was for the KZ. I havent had to buy a bettery for the XJ in awhile.

 

Update: Well, I did a compression test last month and the readings weren't good and got readings of about (I'm going off memory) #1 110 #2 120 #3 115 #4 70. Changed the shims, and readings were closer together. But last week I did a wet test and compression improved dramatically to around 150 across the board except #1 which went to about 180.

However, after letting the bike sit for a week I did a dry compression test and the readings were pretty good. 120 psi for 3 & 4, and 110 for 1 & 2. Fired her up, and boom she started. I'm assuming I seized the engine if the bike started after putting a teaspoon in the cylinders?

But I'm still having problems with the idle. One moment it's idle at 1500 rpm and after several minutes it shoots up to 5000 rpm for some weird reason. I'm gonna take the carbs off next weekend and take a look.

It's also smoking a lot on the bottom and the right part of the head where 3 and 4 are at. I'm guessing there's an oil leak at the bottom causing all the white smoke to come out, but I don't know why white smoke would be coming out from the top.

 

your carbs are out of sync that's all. They were probably done with the valves out of spec. Just in case check for a vacuum leak