My oil light is on and I don't know why!

[skids]

Re: Re: John Stewart's air filter

Originally posted by johnstewart
Yep, nail on the head. 79 and Uni. I threw the damn thing away after I got it back off. Super annoying. I take it this has come up for you? =)

I ordered 2 of the filters from JC Whipme, who clained that they were OEM quality. I installed both of them in different model 78E's (I have 2). Then, one night after struggling to get the air box apart with channel locks and visegrips, I finally came out of the kitchen with a big Jin-su knife, explaining to my wife (hot on my heels) that it was ABSOLUTELY necessary. I pryed the airbox open enough for the knife to "saw" that filter into pieces, just like the tin cans in the commercials. As I sat there on the garage floor, half crazy, bloody knuckles, I had a very sick reconning...the OTHER BIKE HAD ONE INSTALLED ALSO! Luckily the hitch pin was able to tear the foam on that one after a lot of effort.

[TopCatGr58]

Hey John,

I didn't realize that you were going to take the pump apart like you did, or I would have given you the clearance specs for the innards, they show measuring gaps with feeler gauges. I hope you had a manual to refer to?? Cause even if the pump "Looked" okay, it could have been worn beyond the tolerances allowed by Yamaha, and that could still contribute to reduced output!?!?

The clearance for inbetween the outer ring and the housing is:
.0035-.0059 in(0.090-0.150mm)
The clearance between the inner 4pointed star rotor and the outer 5pointed rotor: Max: .0047in(0.12mm). If beyond, they say to replace these parts!!

Since you didn't use Locktite, you should be able to take it apart again rather easily to check these values!?
T.C.

[johnstewart]

Should have known!

Okay... finally got everything put back together, started it up... oil pressure light out! Whoo! Then I took it for a spin.... light on! Light off! Light on! D'oh!

So I got a tee so I can have the idiot light and the pressure gauge at the same time.

Yep, it's not a pressure issue. The pressure is rock steady according to the gauge, but the idiot light seems to come on and off intermittently. I can find no consistency or pattern, other than it seems to be staying on more and more often.

Damn! So, I should have figured from the start, it was an electrical problem after all. These bikes seem to be rock solid mechanically, but as you all know the electrical systems can have, ahem, "issues" after 25 years. =)

Well, it was an interesting experience digging into the pump, anyway.

So, the question is... where are my electrical gremlins? So far as I can tell, all other electrical systems work just fine; it seems to be affecting only the oil light.

Tkat from the triples list wrote:

Been 1/2 acidly following the thread figuring one of our much more
knowledgeable wrenches would know the answer. I had the pblm on one of my
XS's. My trbls were traced to a "black box" that lived under the seat. It
was years ago & I don't rmbr what else it controlled/monitored. But after
I changed it out the oil light behaved. Oh, it was a Spc. if that matters.

I've got a spare bike, so it should be easy to swap out this "black box". However, I've no idea where this might be. Anyone know?

I won't go into details on the *very* *very* strange things this bike was doing after I washed it (I assume the high pressure water got into someplace it shouldn't), because it was so weird I'm still thinking perhaps I was hallucinating.

johnS

[johnstewart]

AHA! I think I've figured it out, and most of you aren't even close (if I am).... more to come when I know for sure. =)

[capocrimini]

Yes, I had that problem a year or two ago (and I think it WAS Tkat that offered the same suggestion) to replace the ignition box under the seat. Pressure wash around electrical stuff is a big no-no on bikes, so I've heard, and I've had the red light problem come back and plague me, RIGHT after a high pressure wash where I ventured under the seat. However, I'm going to check all the sending unit and ground issues first (as you did) before trying to find a replacement to the ignition. However, since you have a spare, it looks to be a couple nuts/screws (maybe 3, just going by memory) and the plugs into it. Hope this solves it for you. I've ridden over 1k with my light on, and the engine isn't dead yet (plan to rebuild and big bore in the future, so I don't mind so much if I wreck the motor a little, except its my only bike). Its also nice to know that the oil pump isn't that hard to change out, I was dreading having to split the case in "case" of a bad pump!

[johnstewart]

Ya, the pump was relatively easy to get out. No big deal at all. I was worried as my competence is suspect in this area, but I managed.

Not sure why you refer to the ignition - that's never been an issue for me.

In regards to the oil pan allen bolts - does anyone know the torque specs for these? I can't seem to find the appropriate listing in Cylmer nor the Yamaha shop manual.

And when I put them in (without a torque wrench), I think I was a little wussy - I didn't want to strip out the aluminum - so now it leaks...

[capocrimini]

The black box under the seat is the ignitor unit.

[fusionking]

You never said what the pressure was driving down the road. Can you read it then? Maybe you have a "GHOST" brake lite wiring problem, you know, one that comes and goes unless you put a load on it. There are numerous connections on the brake lite circuit that could lose connection for a split-second and make that light flicker. That is if your bike is like my SF . It just seems like a very logical place to be looking because they are wired together (which to me seems VERY un-logical) I know I almost wrote-off Battle Cat untill I realized It had old wiring problems back when I first started working on it. That just might be why I own it now! Garry

[johnstewart]

Originally posted by fusionking
You never said what the pressure was driving down the road. Can you read it then?

Ya, it was fine. I think usually around 60psi.

[johnstewart]

The Reason

The problem was low voltage (apparently) in my battery which was caused by low fluid levels. I topped it off with the $0.66 gallon of distilled water I bought, and the oil light behaves normally (so far; not yet been dry enough to get out for a long ride).

Apparently the sensor was flaking out at low voltage levels.

Before I topped off the battery, I noticed that the light on/off was correlated somewhat with what you would expect for low battery - after a long stretch at relatively high RPMs, it goes off. In stop and go traffic, drawing more from the battery without much charging it, it went on.

Pretty freaking weird.

Of course, I'm only 95% sure this is the issue - like I said, still no long ride. Plus I need to fix the oil leak I made (thus my search for torque specs).

Thanks, though, for all the suggestions and help!

[beechfront]

MY 2 CENTS

the behaviour you're seeing sounds exactly like what i was experiencing. It made no difference if it was under load, idle, whatever. and after worrying my ass off and hooking up the oil pressure guage to find out it was not a pressure problem - i had not even noticed that the light would often be off while the bike was not running. (duh! obvioulsy electrical).

i am not going to mess with it. i've read a lot of posts on here and have yet to read one where somebody lost an engine due to lack of oil pressure.


Anyways, have you gotten your bike warmed up good? i was getting 60 psi very consistently until it got warm. seemed like it took a good 1/2 hour to get up to operating temperature then the pressure would go down quite a bit, and at idle would barely register (1-2 psi?).

[Jdwags]

Oil lite is also Brake light out circut

I had the same problem with the Mongrel..

That light circut is also the brake lite out warning..

Mine was a bad connection at the brake light

after I had done everythign i could think of about oil...

changed the bulb and greased it up.. problem solved..

[mitch]

oil pan torque

7.2 FT LBS on the oil pan bolts yer welcome !