Crankshaft rotaion question?

Which way does the crank shaft rotate if i am looking at the lil gold timing plate on 1983 xj750 seca?

 

in the same direction as your tires when cruising down the road.

<facing forward not backwards or going in reverse! >

it'd be counter-clockwise if you look at the crankshaft from the left side of the bike

 

All right then so thats right, i got fuel, air, spark But no boom, Or sometimes only a lil boom barely audible. So what is the problem then, timining?

 

battery too weak? see what kinda volts it has while your tryin to start her. it may crank fine but not produce a hot enough spark.

 

no its sparking really hard volts are good, everything is spining and doing what it should but not at the time taht it should, if you know what i mean.

 

Have you checked compression? Fuel delivery?

 

im getting fuel to the pistons but and i have compression yes.

 

Ok, If it were mine i'd start with checking valve clearances, and the cam timing while the valve cover is off; then move on to checking the ignition pickup and all associated wiring. Eliminate everything in a systematic fashion until you find the trouble. Assume nothing! One thing at a time so you're not running yourself in circles.

EDIT I R dumb....if you suspect that the spark timing is off....put a timing light on it.

 

Will it run on ether?

Also, Is this just a problem that popped up? or is this a bike you are working on getting going? I was recently working on a bike that an owner recovered from a collapsed garage, i tried to start it once and it blew up on me, yeah I was getting fuel, LOTS... you don't even want to know what those carbs looked like inside, i should have taken pics.

 

How much compression?

Also, are your spark plugs new? Sometimes plugs can spark fine outside but put them under compression & they fail then. It can be very misleading, to the point that I always fit brand new plugs first with any non-start just to rule them out...

 

yes i've tried the noob stuff all ready. And i am planning on throwing a timing light on this afternoon, So this is new problem i rebuilt the engine and on reinstall it got all squirelly wont start. So i will get it eventually.

 

What compressions do you have though? just interested to know.

 

So it wont run on ether? I dont mean to tell you to try this as a noob fix to get it running, its just an old school diagnostic. if you can't get it to run on the sauce I would suspect ignition problems.

 

The timing is fixed from the ignitor, if you had the cam chain off (you said you rebuilt), maybe you got it lined up wrong (CHECK THIS) if it's off you could be bending valves.

 

+1

 

I did a bad thing. I made an assumption. I assumed that the PO had already confirmed that the valve timing is correct. My thinking about the timing light was that he'd be able to diagnose any potential, intermittent, electrical fault that might cause a weak spark...though that's not great advice either now that I've thought more about it.

 

so confused idk what your telling me here guys it wont fire on the sauce because the timing is off. In order to get a boom you need 3 things fuel,air,and spark and you need them all at the same time if just one element is out a wack just a we bit you are just gunna end up with cylinders filled with gas. So i go the timing mark on the satator all line dup and i have the valve cover removed, so now im gunna attempt to rote the cams into alignment while the motor is in the bike but idk how well this will work

 

STOP! Do you have a shop manual? Go no further without proper instructions.

 

You need to remove the tensioner first.

Shop manual may save you making some basic errors.

You have determined the valve timing is actually out? And you are aware that that setting the crank at the marks does not always make the cams line up.

The cam alignment marks will only line up every second turn of the crank.

 

Still not checked compression for me?
I only mentioned this since if the valve timing IS out (and it may be) you will see low readings.

Also, I know it's not exactly sound engineering practice to diagnose valve timing with a comp test, but as the OP has already been trying to start the motor, if any valves could've got bent, they already will be and a compression TEST and posting the figures will gve us a clue as to whether we have issues in this area or not without the need to pull the valve cover.

 

wanna find out real quick hook up a air hose to the spark plug hole you got bent valves that will tell you real quick

 

Umm, let's quit recommending any more spinning of the motor until the cam timing has been confirmed. These are "interference" motors.

SETTING THE CAM TIMING IS NOT AN "INTUITIVE" PROCESS; it's not something you're going to just "figure out."

YOU NEED A SERVICE MANUAL, or at least the full procedure from the service manual to get this right. Hopefully, you haven't bent any valves yet; but don't keep trying to fire the motor (or test compression) until you're 100% sure you have the cam timing correct.

 

Well I have already stated that i am waiting for a frickin shop manual. And if this site isn't specifically for getting information that would be on a shop manual, then whats it for a bunch of posers sitting arround talking about their freaking XJ's,, LAME. Why don't you guys scroll thru the posts and look at how many tell me to buy a manual. SO IF YOU KNOW WHAT YOUR DOING THEN GREAT I APPRECIATE THE HELP, BUT IF NOT THEN DON'T OFFER ANY OPPINIONS ABOUT WHAT YOU THINK IS WRONG THEN GO TELL ME TO BUY A MANUAL. CUZ YOU KNOW WHERE IM GUNNA TELL YOU TO STICK THAT MANUAL.

Now that that is cleared up i tried the timing again following those strict instructions that RICKOMATIC posted n another thread that i can't seem to find. So this timing adventure this time is closer i think. But i only have tiny little ttming mark on the end of tyhe intake crankshaft but nothing on the exhust so right now at tdc my #1intake lobe is pushing down the valve and my #4 exhaust valve is pushing down the exhaust valve, is that right???????

 

Well honestly then I'd recommend waiting. At least quit screwing with it unless you're trying to bend a valve or four.

But since you insist:

There are little arrows cast onto the edges of the tops of the inner cam caps. Not the larger arrows on the tops of the caps, tiny arrows on the edge that rides against the cam.

There are little "dots" drilled into the flat flange on the camshaft that runs next to the caps.

When the "T" mark on the timing plate is aligned with the pointer, the little dots on BOTH camshafts need to be aligned with the little arrows on the cam caps. Period.

There is a "procedure" to get this right. If you'd like to PM me with your email address, I'll scan the pages from the Haynes for you.

Be sure you have a torque wrench that is accurate at 15 ft/lb or so; the camshaft sprocket bolts need to go to 14.5 and it needs to be accurate.

And quit turning the motor over until the timing is correct or you will bend valves.

 

32, we know you're frustrated but maybe you should lighten up a bit? The information/procedure that you're asking help on is not easy to explain in words, which is why you're getting the response (get a service manual) that you are.

Blasting away at professionals is just not real good form.

BigFitz is being more than generous with you.

 

Hey, I'm trying but it seems to be an uphill battle.

--I read back through this thread and at least one of your others and see no mention of a shop manual on order. So forgive me for suggesting you need one.

--the instructions that Rick posted were in YOUR other thread, just a couple of days ago: http://xjbikes.com/Forums/viewtopic/t=42090.html

--the timing marks are not on the ENDS of the camshafts. They're on the flanges that ride against the caps that have tiny arrows on them.

Again, PM me with an email address and I'll send you some scans. They have pictures that might help.

 

After reading your other threads stevo, I'm curious how you went about splitting the cases and reassembling WITHOUT a manual. I'm willing to bet there aren't many people here if any that would or could do it without one. Setting the timing might be the least of your worries if you didn't reassemble the cases properly. And this site is not meant to supplement a service manual.

 

Well reading another post I think the timing is believed to be sorted again... I'm not sure what the bottom end's going to be like though after reading about the tight crank/backwards bearing...

I've got to agree with moose I wouldn't strip the bottom end of most engines without having at least glanced through the manual first... With luck it'll be alright though...

 

Sure it is; or at least we try. Supplement; certainly not REPLACE.

 

Thanks fitz. That's what I meant.

 

Its real simple, your not going to do any more damage than is already done motor has already spun over if your valve timing was off and the motor spun over you probably have bent valves. The fastest way to find out is to put compressed air to it you do not need a manual for that. It does not have to be 150 lbs 15 will do just fine

 

Same reasoning behind me suggesting a compression test (any damage would already have been done).

Waiting to hear back now if it is sorted, a post in another thread seemed to suggest the timing was out far enough that no valves ended up bent(!!!) and that he's sorted it now... (a compression test would have shown up the issue after it was originally cranked with no-start, it can not have had good compression as suggested (no figures given) with timing that far out)