Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!watmath!clyde!cbatt!ihnp4!ihlpa!animal
From: animal@ihlpa.UUCP (D. Starr)
Newsgroups: net.cycle
Subject: Re: Flashing Oil Light
Message-ID: <1848@ihlpa.UUCP>
Date: Thu, 11-Sep-86 17:43:59 EDT
Article-I.D.: ihlpa.1848
Posted: Thu Sep 11 17:43:59 1986
Date-Received: Sat, 13-Sep-86 04:28:53 EDT
References: <1271@drutx.UUCP>
Organization: AT&T Bell Laboratories
Lines: 56

> My recently purchased (used) 1982 Yamaha XJ1100J Maxim 
> does a disturbing thing:  When I accelerate VERY hard
> (warp factor 8) for more than a few seconds (RPM = 4500 to
> 8000 through 1st and 2nd gears, 0-50 mph) the WARNING light 
> begins flashing and the LCD display says "OIL", implying, 
> I suppose, that the engine is experiencing oil starvation 
> (the engine oil level is correct with the engine turned off). If 
> I maintain constant velocity (i.e., stop accelerating, but hold 
> constant throttle position) the light seems to stay on 
> indefinitely, and it goes off only if I drop RPMs back down to idle. 
> 
> (1) Does anyone out there know if this is a normal response for
>     this engine (1100cc DOHC in-line four)?  

Can't answer for sure about the Yammie, but it was SOP for the
Kowie Z-1 and its descendants.  
> 
> (2) Does Yamaha position the sump intake in a location where 
>     hard acceleration will move all the oil away from it?

Probably.  The Z-1 had the oil pump in the front of the pan, and hard
acceleration shoved all the oil to the rear.  There were two solutions;
one of them might work for you.  (1)  Oil pump snorkels, which extended
from the existing pickup to the back of the pan, were sold by aftermarket
performance houses.  (2) The Z-1 had a narrow spot in the pan about 1/3 of
the way back.  Some people put a little swinging trapdoor there so that
oil couldn't slosh back under acceleration.  Both approaches worked pretty
well.  You might also be able to reduce the effect somewhat by stiffening
up the rear suspension.  Rear-end squat under acceleration does make a
significant contribution to this problem.
> 
> (3) Is the oil warning system based on oil pressure or does it
>     just indicate crankcase oil level?

Almost certainly pressure.  Nearly all four-cylinder Japanese engines
use plain crank bearings (like a car) and therefore require rather high
oil pressures.  The only Japanese four-stroke engine I know of with an
oil-level light is the Yamaha V-twin, which is all roller bearings and
can't maintain more than two or three pounds of pressure.
> 
> I tried two different Yamaha shops and got pretty unconvincing
> responses. (e.g., "Yup, maybe it'll do that, sometimes!, or "Wow, I don't
> know!")  I have previously talked to the "technical" support people at
> Yamaha's USA headquarters.  While they were friendly and tried to be 
> helpful, they had difficulty answering (or maybe comprehending) technical
> questions. (I am still waiting for a response to, "What is the 
> published engine horsepower for my bike?").  I get the feeling that
> they do have a few gurus around, but they save them for the 
> racers and consulting with magazine writers.
> 
> If anyone out there knows of a really competent Yamaha mechanic or
> shop, I really would appreciate a name or phone number.  
> 
> Thanks in advance!
> 
> Chuck Rogers @ ATT-ISL, Denver