Oil in intake? What is likely cause?

Hi,

I am working on this '81 XJ650 i picked up last weekend trying to make sense of the "mods" that were done and how the bike should be overall.

I got the starter to at least turn the machine over... With some starting fluid, it will fire for a sec...

From outside, the concerning thing i see is oil all over the place. Also, the carbs look terribly neglected.

I took the carbs off today and just as i suspected.. I will be pricing out rebuild kits only if I can nail down this what might have cause this oil to get ALL over the engine.

It looks like oil is in the intake. I took some pics of the intake and the carbs.

Disregard the "homemade" intake boots. I will look for some stock replacements depending on how this oil thing pans out.

Any ideas for what would make oil appear to be in the intake? Should i piece back together and sell for parts at this point or could i fix at a reasonable price?

Heres some pics

Intake:


dirty DIRTY Carbs 1:


Dirty carbs 2:


Thanks in advance!!!

 

I would say that if the crankcase has been overfilled with oil, it could have gotten out through the crankcase vent which is connected to the airbox, themselves connected to the intake boots.

 

Better be checking the airbox and filter as well while you're doing a checklist.

 

As said above the oil is most likely from over filling the crank case. I would clean the carbs and see if it will fire up then make a decision on if it is worth fixing. If you just looking to fix up and sell, it may be worth more as parts. Personally I have a hard time parting out a bike... i see them all as re-buildable.

 

Or a STUCK FLOAT filling up the crankcase with gas, creating said "overfill"...

 

Thanks for the responses...
There was pretty much no oil in the machine when I got it.

Ultimately my concern was engine issues. I have no intentions in reselling it. I went through the trials with my 550 and with the help of this site and everyone here, i got it running.... Then was dumb and sold it.
I plan to keep this bike.

Regarding the airbox, not an option.. As with my old 550, the frame has been modified so the box will not fit.

So, I thank you all for your input. I was just hoping this oil wasnt a known issue that would indicate catastrophic engine failure or something.

Onward and upward.. Will clean up/rebuild carbs, correct valves.. brakes, etc.. I have a lot of parts i need to hunt for and replace like handlebars, pickup a tach and speedo and cables, start/kill switch, clutch bracket/handle. and more i cant think about now..
Thanks again.
James

 

Get the valves in spec and then do a compression test.

That way you'll know if you're working with a viable mill. No sense sinking a bunch of effort into a motor with a holed piston or burnt valves.

 

Good call, BigFitz. Ill focus on valves to make the determination with a compression test.

Any ill effects by testing compression with carbs not mounted on? Bout as WOT as you can get in my mind.

Remind me.. Remove all plugs, disconnect TCI, charge battery completely and test each cylinder 2-3 cranks record readings and fingers crossed all will be consistently well with less than 10% difference?

Thanks!

 

Even better results with carbs off.

Yep, except you crank until the pressure stops rising.

 

How do you disconnect the TCI? I've always left the plugs attached to the wires and grounded them so the plugs fire. Is there any problem with that method?

 

OK... tonight I had an hour to spare to take a look at my bike.

I discovered a couple items that have me worried.

Being that I had compression testing on the mind, i decided to take some preliminary tests. I had not adjusted the valves, or even checked clearances, but i just wanted to get an idea where it may stand.

here are my readings and they have me concerned........
cyl 1 - 100
cyl 2 - 90
cyl 3 - 50
cyl 4 - 110

Aside from erratic compression numbers, while i was testing cyl 1, i heard this distinct, loud gurguling sound... i could not place where it was coming from. I tested cyl 1 again to reproduce the gurguling... i still couldnt pinpoint where it was coming from... I cranked once more and stopped.. right as i stopped, Oil come shooting out of the breather tube pictured here:



So, this same breather tube was connected to the make-shift intake connected to the carbs. SOOOO, that would likely be the cause for all the oil in the intake...

So, inevitably, i have some questions:

1. Are these compression numbers a viable representation of the condition of the engine despite valves not being checked/brought to spec?
2. WHY would oil be gurguling/coming from this hose which i could only think would be a "Breather Tube" of sorts.

Thanks in advance

 

If your #3 carb valves are really too tight, it could cause the readings to be very low on this cylinder.

I'd do the test again as is, and then again but with a teaspoon of oïl added to each cylinder through the spark plug hole. Then it would be interesting to compare your readings with and without oïl.

 

I Will have to check clearances then. I can try the oil in the cylinder. Is this whats termed "fogging"?

As for the oil spurting out of that hose, any idea why would that happen or what it would indicate?
Thanks for your response!

 

If the numbers don't go up much in that low cylinder after adding the oil vs without oil, it will indicate that its probably tight valve spec and the valves are not seating tight enough to get good compression. And if you determine that this is the case for your low cylinder, then the valves for other cylinders are most likely not that far behind. Keep your fingers crossed that that is the cause. But the fact that you are getting oil coming out of the breather hose would make me suspect that you are getting blow by through the rings and pressure is building in the crankcase.

 

SImply too much liquid down there?

 

With those Compression Values and the "Gurgling" you need to have a "Plan-B"

I wouldn't recommend you do anything but take that Bike off life support.
For you to think about rehabbing that Plant, ... you'd need -- NOT one ... but two Money Trees, in full bloom inn your back yard.

The gurgling is that poor Mill's death rattle.
Valve Job
Ring Job.
Honing
Gasket sets.
____________
= Bow-koo Greenie-backsters and the need for two cosigners.

Light a candle.
If your bike was a horse they'd shoot it.

I very sincerely suggest acquiring a used Motor and doing a Heart Transplant

http://www.ebay.com/itm/1982-Yamaha-XJ- ... 56&vxp=mtr.

 

*Sigh*....

I have some awesome news! (sarcasm)

So, maybe to confirm what RickCoMatic stated, here are some findings.

I changed the oil this morning... and.... we had well OVER 2.5qts.. id say a gallon... Also, the oil that came out STANK of fuel something terrible.

SO, that explains the gurguling and spewing of oil out of the breather....

Once i got the oil taken care of, i did another compression check... I will just compile them ALL here for reference:

Cyl1,Cyl2,Cyl3,Cyl4
Initial/Baseline Compression Test:
100,90,50,110

After correcting oil quantities:
110,95,55,115

After adding small amount of oil per cylinder (Approx tsp):
155,155,150,180

Soooooooo... I am suspecting this is no bueno and i better start looking for some seeds to plant those money trees....

Can anyone confirm this is indeed bad and what Rick says is really the case after these findings today?

THANKS!!

 

Rick is 99.44% correct 99.44% of the time...

Good luck to you in your engine search...

 

Thank you everyone for your help!

 

Well maybe you had a stuck ring on number 3 and the wet test helped it get free? Now that you've got the excess gas/oil overfill mix outta there why not go ahead with checking the valve clearances before you give up?