bad clutch?

hey guys, i'm new here, and new to the xj scene. my roomate just handed me his 83 xj750 cause he got a gxsr1000.

Question is (sorry if this has been asked somewhere else. I looked but didn't see anything)... I'm trying to determine if the clutch went bad.

he hasn't used it in a little over a year, but he said while he was using it, the bike was fine except for when he really tried to get on it, the engine would rev and tach up.

I do a fair amount of stuff with cars, so to me right away it sounded like a bad clutch, but i know motorcycles are a little different.

I'm wondering if it sounds like the clutch plates are actually bad, if there is something that could be wrong with the driveshaft assembly (seeing as i know nothing about it yet), or if the oil leak it had/has could lead to a lack of pressure to the clutch.

I still have plenty of work to do to it, but tomorrow i was gonna change the oil, gas, and polugs and see if she can crank first.

p.s. can you jump a motorcycle from a car that ISN'T running?

 

*plugs*

 

OK to jump from a car NOT RUNNING.
Clutch, do you know what oil he was using ? these bikes don't like synthetic.
BTW welcome, Wiz.

 

thanks wiz! I've seen your name a lot around these forums


I asked him, he's not entirely sure what type of oil got put in it, but he brought it to a local shop to be done, so i'm ASSUMING they put the correct oil in it. but then after that, his buddy put some type of engine cleaner in the oil. I had read that these bikes are picky with oil types so thats why i figured the first thing i would do is change out the oil. it also fell over in our parking lot one day during a windy storm so i'm gonna change out the oil, gas, and plugs for that reason also.

i'm also positive that by now the battery has to be dead, so is it safe to jump this bike from a car that isn't running?

 

Wiz answered your jump starting question: yes. However if the battery is stone dead, the bike won't bring it back. You're better off to pull it and properly charge it.

The clutches in these bikes are all pretty much the same; basics here: http://xjbikes.com/Forums/viewtopic/t=29541.html Your clutch will be a bit simpler, as your plain plates don't have tabs to worry about and there's no "clutch boss spring" in the bigger bikes.

Depending on age, "sitting" history, etc., the clutch may need to be rebuilt regardless of actual wear. If the friction plates are petrified they won't do their job very well.

But start with an oil change; use motorcycle oil.

 

Alright thanks, makes sense. And sorry wiz, somehow i just skipped right past that first sentence. And thanks for the link to the clutch, that's going to be extremely helpful.

Does anyone know a good place online that you can order motorcycle parts?

Thanks again for all your guys help

 

Banner at the top of the forums will lead you to XJ4Ever aka Chacal, he's got EVERYTHING you could ever need for these bikes, except a bar-mounted kitchen sink.

 

haha alright, thanks.

a sink would be convenient while working on the bike though...

 

Fitz I just changed the pressure plate springs in my clutch, new bolts and washers, and found the hardest part of working on the clutch is getting everything to line up properly. The pullrod and the throwout shaft, the one in the cover, took me about 4 tries to get them to "mesh" properly so that the leaver was in the right position.

 

Which is a pain in the butt; and I don't know why the book has you do it that way.

All you need to do is reinstall the cover, paying NO ATTENTION to the final position of the lever; then simply pop the clip and move the lever to the appropriate position once the cover's secure.

Why the book(s) go through all the other BS is beyond me.

 

I read that Rotella T 15-40w was fine for bikes. True? False?

My bike just started having the same problems and I wonder if that is the same issue.

 

I actually just called my local stumpys yamaha dealer, and the guy in the service department told me that this type of season you want a good grade motorcycle specific 20w50. I'm guessing if you ride in the colder weather, or if its always cold by you you could use a 15w40 since its a little thinner, but persoanally I'm going to just go to the yamaha dealer and buy the 20w50 they told me to get so that way I can rule out that possibility

 

Sounds like good advice. I live in San Diego so I should probably run 20-50 all the time.

Also, I think Rick had a thread around here for properly adjusting the clutch lever perfectly. The guy is smart and it's free to do the adjustment. So why not?

 

Bad friend, BAD, BAD!!

LOL

If he added anything to the cranckcase other than motorcycle oil, he did a bad thing and needs to be punished.

Change the oil and filter before you tear apart the clutch. It's gotta be done anyways and if it ends up being the clutch you can change that without losing the fresh oil.

Then keep your friend's buddy away from the filler hole! LOL

Oh, BTW, if you live south of the ice-pack then 20-50 will be fine. If you live south of the Mason-Dixon line, 20-50 is probably preferred to help with cooling.

 

Bad friend, BAD, BAD!!

LOL

If he added anything to the cranckcase other than motorcycle oil, he did a bad thing and needs to be punished.



haha yeaaa, hes gonna get a stern talking to when i see him! lol

 

guess i gotta practice my quote button lol

 

On the subject of oil weight, I've run the bike down to about 40 degrees with 20w50, seems fine. I'd say you would only need 15w50 if you plan on putting chains on your tires.

 

ABout the only thing you would NOT want to do is use a straight 50 weight oil when the temp dips below about 38 degrees.

When the temp gets that low, and you add the wind chill on top of that, the straight 50 weight oil is pretty thick.

Thick oil + cold air + cold moving parts = oil foaming. Not the worst thing in the world, but not something I'd want to do to a motor with any regularity.

Same reason the 80w-90 in the hub foams up and overflows out of the breather in colder temps.

 

Umm, tskaz; wind chill doesn't affect things like motorcycles and cars. We humans are evaporatively cooled; the harder the wind blows the more heat we lose. Not so a lump of iron or aluminum.

That being said, you're absolutely right about straight-weight oil. It's a high-revving, plain bearinged, multi-cylinder motor; not a Harley Davidson farm implement engine from the early years of the industrial revolution.

Multi-weight motorcycle oil, in the recommended weights (although running 20W50 in place of 20W40 is fine) is the only thing that should ever go in the crankcase. Anything else is asking for trouble.

 

I said wind chill, maybe wind cooling would have been a better choice of words?

What I was actually referring to was not the standard "wind chill" the weatherman (oops, weatherperson) talks about, but the cooling effect of the airflow over the head at 60MPH with a 38* air temperature.

This would keep the engine cooler and not allow it to fully warm up on a 2 or 3 mile ride to work or school.

I apologize if my choice of words caused any confusion.

 

oooook, so, i changed the oil, fixed the filter miss-hap, went to change the plugs but they were fine, so i left them. (reason i left them was i ran into a problem, but i'll get to that later). Filled gas (premeium 92 octane), hooked the bike up to my car via jumper cables (car was never running) went to go start it, and all it did was crank. it sounded like it tried to fire maaaybe twice.

I had the petcock to PRI setting, and the choke I had pulled towards the handle. seeing as how i wasn't sure which position it was supposed to be in i tried away from the handle as well.

i pulled one of the spark plug wires and then cranked it to see if i was getting a spark and i didn't see anything readily noticable (not sure if i'm supposed to but i figured i should see something)

any ideas?


also when cranking the motor i couldn't really crank it for more than 3-4 seconds at a try because i would get a frinding noise, the engine would stop turning over, but the starer continued to spin. I asked my buddy who gave it to me about that and he said he had the starter changed, but if contined to do the samething. Does that mean bad flywheel teeth?

sorry for the length, i just wanted to give as many details as i could

 

to add, the cranking times were anywhere from 1/2 a second to 3-4 seconds because this problem was not consistant in when it would occur. Sometimes if would only make the grinding sound for a split second and then it would start turning the motor over again

 

spark plug problem was...i think the spark plug terminal got stuck in the plug wire. when i pulled the wires off i looked at the spark plug and it had a post with a thread on it. the new spark plug (samek exact model number) didn't have a post with a thread, it had a cover over the threaded post.

did it get stuck in the plug wire?

 

OK! lesson learned...

If your spark plug terminal ever breaks off in your spark plug wires, do NOT think you're doing a good thing by putting dielectric grease on the threaded post and inside the wires.. you will just never get a spark.

went out and cleaned out all the di electric grease and she purred like a kitten. after a min or so lol

still have the starting problem. bad fly wheel?

 

There is no "fly wheel" like a car. The starter is engaged via a "sprag" clutch that is VERY sensitive to using the wrong type of oil.

Exactly what oil did you put in it?

Also, the plugs SHOULD have just the threads on top. The little "cover" (which is for a different type of terminal) just unscrews.

 

Ahh. Ok, good to know, now I can actually change the plugs. Thanks fitz.

As for the type of oil, I do not know what type of oil was used before I got it, but I'm going to assume the worst and say some type of regular car motor oil. I do know that there was some type of "cleansing agent" poured into the engine oil. I drained the oil, put a new filter, and used yamahaline brand oil (made for motorcycles) 20w50

 

YAMAHA is NOT, ... nor ever was in the OIL Business.
YAMAHA is in the Bottled Oil with Yamaha printed on them business.
You get hosed every time you buy Yamaha Oil.
'Cause the ONLY thing Yamaha about that Oil is the Bottle.

Do yourself a HUGE Favor and get a Yamaha Workshop Manual.
The Manual comprises the Owners Manual and Service Manual.

The dough you spend for the book gets saved the first time you look-up what to do and get it done all by yourself.

 

Bah, alright. Well what brand/name oil is sufficient? I'm assuming I should still be using 20w50.

I have a haynes manual on the way, would that suffice?

 

Rick's right, and he's only trying to save you some coin. Yamaha doesn't make oil any more than Honda or Harley Davidson do; it's somebody else's oil in their name-branded bottle.

There are a lot of good, conventional (or even semi-synthetic) motorcycle oils out there. Castrol 4T is commonly available; the AutoZone in my neck of the woods carries either Valvoline or Havoline, I forget, but it's JASO-service (real motorcycle oil.)

The point being, it doesn't have to be manufacturer-branded as long as it's motorcycle specific. I use Castrol and Spectro myself.

As for manuals, the Haynes is OK unless you're going to go deep into the motor. Then you'll need a factory book to fill in some of the glaring omissions in the Haynes; I find the best thing is a combination of the aftermarket and factory books.

 

O, don't mistake my frustration, it wasn't towards rick, or anyone else. I appreciate your guys help immensly. I'll do another oil change with a different brand motorcycle oil (maybe castrol or exl) over the weekend and see how that goes.

Now being that I may be having a problem with that "sprag" clutch, should I use a semi-synthetic motorcycle oil, or just a regular motorcycle oil?

 

Stick to Dinosaur juice. (Conventional oil.)

If your bike sat for a long time, it may benefit from a couple of shorter-than-normal oil change intervals.

 

Alright, you got it fitz. It appears that my oil drained out on its own in the past 2 days, so it kinda changed itself. Lol. It appears that it leaked out of the drain plug, so I will be getting a new drain plug, o-rings, washers, and a small torque wrench so I can torque the filter bolt and drain plug to the proper torque spec before I do another oil change

 

This might be the stupidest question anyone has ever asked.... but when I stand my bike up straight, the oil level window is covered with oil, and when I lean the bike on the kickstand its about 3/4s of the way full. Does that mean I have enough oil? Or is it low?

 

and when its running, its inbetween 1/3 to 1/2 of the way full

 

WAY TOO MUCH!!!

On the kick stand the window should be clear of oil.

Running and on center stand the window should be clear of oil.

Check level on center stand, engine at least 10 minutes cold.

Oil level when cold on center should be just to the top of the window, with a small bubble showing.

Run it the way it is and you'll be replacing a head gasket and possibly some rings VERY soon.

I don't know what the capacity of the 750 is, but it is stamped on the top of the clutch case right next to the filler hole.

The capacity is in cubic centimeters. For example, the 650 is 2500CM3, or 2500 cubic centimeters, or 2.5 liters.

Then run the motor for a few minutes to circulate the oil.

Then shut it down and go have a cup of coffee or a pop (soda to those of you that don't live in Michigan LOL)

Then recheck level and you'll add about another 300cc's slowly until a slight bubble is showing at the top of the window.

That's for a 650. A 750 might be slightly higher, but still works the same way.

 

Our glorious 750s take the same amount, 2,500cc (not counting filter change, that adds 300cc). But procedure is still the same.

 

tskaz is right, you're overfilled. Once you get it straight, better check your air filter. Too much oil and it will pump out the breather into... you guessed it, the airbox.

 

Alrighty, so just so I understand 100%.... when the bike cold and is on the center stand, the oil level should be juuuust about full...then when running (still on the center stand) the oil window should be clear. Then wait 20 min, come back out to it, and it should return to juuuust about full?


Assuming that's correct, if when I come back out to it in 20 min and the level has gone down, should I add more till its juuuust about full?

 

Yes, that is correct.

In regard to adding more; sure, just a little. You want to see a "bubble" at the top. It's your insurance against a stuck float overfilling your crankcase. (If one day the bubble has suddenly disappeared you know need to immmediately investigate.)