A little bit of everything...

If you don't like reading, the problem is oil in the air intake from the crank case vent... otherwise carry on.

Alright, first off, I would like to apologize for making a new thread for problems of which I am sure there are 30 plus threads for each of already, but for some reason, no matter how hard I tried, I could not for the life of me get the search function to work. I don't know if it's just one of those days for me or what, but I tried searching and it wasn't having any of it. I also went through the first 35 pages of threads before I just kinda gave up and decided to just ask as that would be much easier. Now that that's out of the way, lets get down to business.

Now, the bike in question is a 1981 Yamaha XJ 650R as told to me by the insurance company when they ran the vin number the first time. I don't know how to tell bikes apart very well, so that is what I figured it was... I am a walking car encyclopedia, but when it comes to bikes... ehhh... I'm not so good. So naturally when I was told that's what it was, that's what I believed, and so far that hasn't lead me astray yet.

This thing was abused and beaten to hell by its previous owner which is probably how I got this thing so darn cheap. when I got it, it only ran for about two minutes at a time and could barely move itself under its own power, the tires were flat, the rear fender was made out of a cereal box and some putty (Frosted Flakes... not kidding), the turn signals were Velcroed on and were some horrid LED... things, the brake light was a trailer brake light lens with one of those flexible LED strips from Walmart mushed inside of it and held in place with duct tape, the seat had been chopped to make room for more cereal (I guess?), the wiring looked like hell's spaghetti, the airbox had been ripped out and swapped for the worst pod filters you would have ever seen (the guys glue hadn't held for half of them), the rear brake had a bolt jammed into the adjustment arm and was held in place with nothing but friction, scrapes and dings up both sides indicating that the bike had been laid down on both sides many, MANY times, and the entire bike had been painted black... and when I say the entire bike... I mean the ENTIRE bike... carbs, engine, exhaust, chrome, brakes plus disk, wheels, tires, shocks, springs, and all... then added a couple splotches of red into the mix. Why did I buy this thing? Great question... I am not even entirely sure thinking back on it... guess I like a challenge or something... or maybe I have a death wish.

Welp, fast forward a two years and burn some money and I had this thing running better then it probably had in 10 years. I got so good a rebuilding the carburetors that from shut down to startup I could take out the carbs, dissemble them completely, clean them, re-tune them, reassemble them, and shove them back into the bike in under 40 minutes. Now that may not be that impressive to some of you who have had these things apart so many times they could put them together blind folded, but I felt that was pretty good for me. I cleaned the hole bike up, got all the paint off the chrome and other important bits (especially the tires... who does that?!), put in all new brake shoes in the rear, new linkage rod and adjuster, real turn signals off a real XJ, a real back fender from some bike... nice chrome one, a real license plate holder, an awesome 30s brake light off some old Chevy truck, a real air box with real rubber boots and a real air filter, new oil and filter, add in some shitty looking welds with a shitty welder for looks, and in general just fixed it up to run pretty darn good for not much money (in terms of bike maintenance that is). All in all, the thing kinda looked like some sort of rat rodded cafe racer if that is even a thing. I liked it, and rode the hell out of it... loved every second.

So.... fast forward another year and its time to pull it out of storage for the winter... today that is. Decided to give it an oil change before I ride it this year. Seemed like a good idea to me. Went off without a hitch and was smooth a change as an oil change could be. I made sure to use 10W-40 Motorcycle oil as per what I had found from the inter-webs and to give it exactly 3.5 quarts just like it asks for on the side of the engine. All is well. Fire it up, let it warm up a bit, and then rode it around in my yard a little. Ran like a dream. It was getting dark out so I decided to park it in the garage for the night, so I popped it onto its side kickstand instead of the full stand (not sure of the real name here) and just let it idle seeing as all I had to do was go in and open the garage door. Came back out 15 seconds later and see smoke just pouring out of the exhaust... well... that's not good. Ran up to the bike and shut off the engine out of fear of hydro-locking the engine with oil (again, probably a real term for it but I don't know what it is).

Once I did that, oil began POURING out of the airbox! I mean like a full on oilfall of about a quart and a half of fresh oil just came pouring out of the airbox! Feeling completely dumbfounded I began digging into the engine bay and airbox to see if I could find the source of the oil spill. Ended up coming across a crank case vent that entered into the airbox at the front most point... I then mopped up all the oil from the inside of the airbox with a couple of rags and pulled the spark plugs to get as much oil out of the engine as I could. Once done I fired up the engine and paid close attention to the crank case vent (pointing away from anything important except a rag preparing to get blasted). When the bike was on its full vertical stand, it didn't have a drop of oil coming out while running... even with a little rev or two up to about 3ks... nothing... curious, I popped the bike down of the full stand and leaned it over on the kick stand again and immediately, drops of oil began flying out due to the high internal crank case pressure exiting the tube at the time... still curious and too stupid to see what this could potentially imply, I revved the motor again... same amount... to about 3ks... and low and behold a fountain of oil came blasting out of the tube at about the pressure of your average water fountain. This time I killed the engine out of fear of it all of a sudden having such a small amount of oil in it.

So the real question... have any of you ever had a problem like this before? Could the bikes horrible former life have finally caught up with it? Is it being possessed by demons and they can only get out through the oil? I will probably have a bit better of an idea after sitting and pondering on it for a while, but right now I am kinda still in that dumbfounded state of "What the hell just happened?"

Now I have done a little research on here and came across a thread that talked about an "oil splitter" that could be either clogged or broken of some sort causing issues with the crank case vent. Granted that guy had trouble with gas coming out of his carbs and filling his airbox... something that I experienced before, but fixed a while ago and haven't had any issues since. The only other issue I have had down there is that it had been starting to jump out of second gear under hard acceleration, or just refusing to go in at all sometimes... I didn't have that problem today, but I never went above 3500 RPMs today either. Could these two be related? Is the transmission receiving to little oil because of this splitter? I have no idea right now.

I apologize about the huge post, but I think that the way this bike was treated before I got it might be a big part of what is going on here... is it something I could have done stupid? Possibly... wouldn't be the first time (obviously) but what it would have been I have no idea. Any help would be appreciated. Also, if any more information is required or pictures or something, I can easily add that as well.

 

you have a 81 seca?
does the vin contain 5v2
1982 XJ650 Seca USA : 5V2
1982 XJ650 Seca Canada: 5V3
or
1980-81 XJ650 Maxim USA: 4H7
1980-81 XJ650 Maxim Canada: 4H8

1981 XJ650 Midnight Maxim USA: 4W5
1981 XJ650 Midnight Maxim Canada: 4W6

TECH TOPIC: Model ID and VIN's
could be your carbs are leaking gas into the crank case
3.5 quarts is wrong

DID YOU CHANGE the filter if not 2.35 liters 5 pints 80 oz


its 2.95 liters 6.2 pints 103 ozs 3.2 quarts by the haynes manual for a 650 WITH FILTER CHANGE

put the bike up on the center stand and look at the sight glass oil level should be between the lines with air bubble
XJ750 manuals
also haynes 650 manual free down load

 

You are correct on both accounts... it is a 1982... my finger must have slipped and caught the "1" key by accident or something... my mistake. Same with the quarts of oil... meant to write 2.5... got 3.5 instead somehow. I would change it above so others could read it correctly but I can't for the life of me find the edit button. Not my day. Also the oil looked pretty clean since the last time I changed it so I did not change the oil filter. Didn't think it looked like it needed it. Granted if that's the case then it looks like I overfilled it a little anyways.

As for the glass window... mine is not opaque... at all. It looks as though someone has burnt gray clay to the insides of the window which now it is impossible to see through. I have no idea how one would go about addressing that problem but it is one that I currently have.

 

Somehow the computer registered me pressing the Post key twice and wont let me delete this double post... just not my day... disregard this message.

 

Picture?

 

Drop the oil... pull the clutch cover off and clean the oil window... then proceed woot!

 

Unless you are a Premium Member you only got a short window to delete or edit your post.

it will be at the bottom of your post

 

Sure, what of? or do you just want a couple pictures of the whole thing.

Yep... I guess that is today's procedure... I'll check back in and tell you all how it goes.

Ahh... that makes sense. That would explain why I din't see one on the first post because it was about an hour or so later when I responded.

 

Sniff the oil. Does it smell of gasoline?

 

Well, pulled the filter and drained the oil... It doesn't have the slightest wif of gasoline... However, dispite overfilling the bike a little... This is all that came out. (See image)

Naturally this is a bit worrying to me, because that means that it spit out nearly all of its oil into the airbox and onto the ground. Also, the reason it is so dark is because it was dark purple when I put it in. The only stuff they had at the store the other day was royal purple so that's what I got.

The airbox on the other hand was absolutely loaded with oil... The lower, more frontal area of the air box had about an inch to an inch and a half of oil in the bottom of it... That is mildly scary.

Edit: Disregard that last bit of information... The rest of the oil has made itself known... It just took a little longer then expected.

 

Sounds like a possible head gasket failure, allowing the crank case to become pressurized. Then, when the bike it tilted left, and the oil level higher because of the tilt... the pressure is forcing the oil level one the left side to be blown through the crankcase ventilation up and into to airbox. Whew the bike is on center stand the oil level is lower than the tube ( and the gaskets under that left side cover.... And there are a couple gaskets and covers in the inside of the shifter cover..... Maybe one of THEM is the problem)

 

That's is definitely possible... How much air is supposed to be coming out of that hose? Last night when it was running and I could feel the air, it had a fairly substantial amount of air coming out of the tube... About the same amount of air as would come out of a low ideology car exhaust... So nothing crazy, but more then I would expect.

 

The breather is pumping nearly the same volume of air as the combustion chambers are; it's just at a much lower pressure.

 

he also has a shifting problem
when you fix that that would be the time to replace the seals for the shift lever and other seals

try a led light high intensity lite to check you oil in the window. before you remove the clutch cover you may want to get the gasket.
you can become a premium member I think you can do it on a monthly basis

 

Do a compression test and/or leakdown test.....

 

Ok, well that makes sense then, that feels about that I am getting out of the tube... Also, I have pulled the clutch cover and clean the little window, put on a new gasket, put in the correct amount of oil according to the little window,

I am now about to do a compression test so I'll be back with that shortly.

Edit: Starting from the left most cylinder and moving right.

125psi. 110psi. 112psi. 120psi.

Those doesn't seem to bad to me...

 

650, 750 air-cooled engines:
Minimum: 128 psi
Standard: 156 psi
Maximum: 171 psi
Max. variance between lowest and highest: 14 psi

 

Ahh... So I'm basically on the very limit then... Well doesn't that just figure. On the plus side, it's not leaking oil out of the vent tube any more. On the downside, it looks like I might need a head gasket or some new rings... Or perhaps the valves are out of adjustment... Could be anything I guess.

 

did you do a cold comp test?
also did you put some oil in for the second test?
you need to get a leak down test

read about how in this link lots of theings in there
The Information Overload Hour

yes you should adjust /check valve clearances first
AIRHEAD VALVE ADJUSTMENT with Pics

 

Did you account for your loacl barometric pressure?
Got to do that in addition to all of the above.

 

I like that information overload thread... I bookmarked that one as it looks like the end all be all of anything that can be done to these bikes.

So after reading the entire compression test section what I basically did was a cold test without oil... But I didn't take the air filter out or open the throttle up to wide open so the pressures would be a a fair way lower then normal.

I also did not account for the current barometric pressures (apparently it was 30.26 in/hg or about 14.8 psi) which when I do I get...

139.8psi. 124.8psi. 126.8psi. 134.8psi.

But that's all for not because I did the test wrong anyways...

Ok, so now that I know what the heck I did wrong and the correct procedure, when I get back I will do the proper compression tests and then get back on that... At the moment I'm out of town so it may not be until tomorrow.

As for the valve clearances, I can't imagine the previous owner ever adjusted them. Probably for the better honastly... But luckily the engine makes just the light ticking sound like described in the thread, so they might not be to far off (which is nice)

Also I would like to do a leak down test but I do not believe that I own the equipment to do it... However I think I know someone that does, so I'll see if I can get that and then I will conduct that as well.

 

the answers are all found here, all you have to do is ask the question.
it is good that things are working out for you.
welcome to the site

 

I see that and I definitely appreciate it. Most forums don't seem to be as friendly as this place is.

Anyways, I apologize that it took me a little longer then expected to pull the numbers on my bike... the weather decided to take a turn for the worse for a little while there and made it a real pain for me to get any work done on my bike... still ended up drenched by the time I was done with the compression test. As for the leak down test, I know I need to do one, but apparently the guy that I thought had one only has a compression tester and not a leak down tester like I thought they did... so I am gonna have to pick one of them up. Anyways, here is what I got from the compression test.

Piston layout:
drivers side (US) (1)_(2)_(3)_(4) passenger side (US)

Compression test
Cold
Gauge pressure
125psi. 108psi. 118psi. 120psi.
Absolute pressure
139.5psi. 122.5psi. 132.5psi. 134psi.

Cold with tea spoon of oil in each piston
Gauge pressure
158psi. 136psi. 150psi. 160psi.
Absolute pressure
172.5psi. 150.5psi. 164.5psi. 174.5psi.

Hot
Gauge pressure
130psi. 118psi. 115psi. 130psi.
Absolute pressure
144.5psi. 132.5psi. 129.5psi. 144.5psi.

Current atmospheric pressure
29.6 inHg = 14.53psi.

From previous page.
650, 750 air-cooled engines:
Minimum: 128 psi
Standard: 156 psi
Maximum: 171 psi
Max. variance between lowest and highest: 14 psi

So it seems like I do have a rather large amount of variance in there... suppose it could be a dead head gasket?

 

Could be that, or it could be valve clearances that are out of spec on one (or more) cylinders......I'll bet that the clearances on those two center cylinders is way too small (especially on the exhaust side)..................time to check!

 

Well then I shall put that in the next step of my fix!

 

It could also be stuck rings, or a combination of both.

 

Ok, I am putting that last bit on hold for a little while as I have encountered a much more pressing issue at the moment. The transmission in my car let go recently so I had been ridding my bike to work every day as it was now my only mode of transportation. Well, after about a week in a half, I was coming home from work one day and after downshifting into first gear to make a corner (the road home is more windy then the mountain roads in Japan) when I pulled out of the corner to accelerate again, when I went to shift up into second, it didn't go. It was completely stuck.

The ride home was all completely normal otherwise. The clutch still worked fine and the engine did miss a beat. I was just stuck at about 15 mph the whole way.

After doing some reading, this problem sounded to me like the infamous chain guard breaking and getting stuck in the shifter drum. Now I am all game for tearing into things, but is it true that I really need to take the engine out to fix this? It sounds like it is a fairly big job and was just curious how big of a job this was gonna be?

 

Read:
http://www.xjcd.org/emergency_guidectomy

 

Thanks for that real quick reply and link... But I think there is another problem at hand here as well...

I did everything that it said to the letter, took out all the plastic and what not, but I still can't get the shifter cam to rotate. It seems to be stuck fast. I can still articulate the shifter just fine, but in terms of actually getting it to change gear, I've got nothing. Also, as you can see in this picture that I uploaded, the shifter gearwheel seems to be missing a pin to allow the shift lever to grab it and rotate the shifter wheel... Is there supposed to be a pin there? I would imagine there would be seeing as every single other gear has a pin ...




Right now my bike is stuck in first gear. I can't get it to shift out of that gear into any other gear despite using the clutch (which does still work) and rocking the bike and doing all sorts of other things to try and get it to pop out and into gear... But I can't seem to get it to do anything. Any other suggestions?

 

Sometimes the plastic gets jammed into places that you can't see. Do you have access to air? Try shooting air around as you turn the back wheel to maybe shake the plastic loose.

Also make sure that you turn the back wheel so the gears can line up, otherwise it won't shift. There are no synchronizers in motorcycle transmissions; the gears have to be moving so they can align.

The shift drum pins are correct. If you had another pin you'd be able to shift directly from fifth into first (early japanese bikes could do just that, with obvious consequnces). The extra hole is so the part can be used in other applications.

 

Yup, gotta keep turning the back wheel as you try to shift

 

Huh... Well, that's good to know because I just figured it was something else that was broken... There have been more bad parts on this bike then good so it really wouldn't have surprised me in the slightest.

And yup, was rocking it but apparently not far enough. Hurriedly reassembled it because I could see a rain storm coming (bearly got it in before the downpour) and when I stood it up I really rocked it a good distance with the clutch pulled in and it went into all the other gears... Thank heavens for that... I am going to have to eventually replace that guard though and I feel like that's just going to be nagging me in the back of my mind every time I look at the thing :/

 

Pic #2... The shifter mechanism is not fully seated. The paws should be in alignment.

Gary H.

 

The chain guide nagging at you? Yes. The guideectomy is a temporary solution. Without the chain guide the alternator chain will slap around and wear through a fairly expensive oil nozzle, spreading little bits of steel thorough the engine. This is a bad thing.

Get her running and then tear teh ening down this winter to replace the guide, and rebuild the starter clutch.

 

I will definitely do that. As disused earlier in this thread as well, that would probably be a good time to adjust the valves while I have the thing torn apart and out of commission anyways.

Well, the shaft that the shifter rides on could slide in and out a little with the cover plate off of the bike. When the plate was on it couldn't do that at all. Should I be concerned if it could do that at all with the plate off?

 

No. Just make sure it's seated when you're shifting gears.

Gary H.

 

Ok, thanks, I will make sure I check that before I do anything with it.