From: Roar.Larsen@termo.unit.no (Roar Larsen)
Subject: HELP!  FJ starting problems
Organization: SINTEF, Norway
Date: Mon, 14 Sep 92 13:16:27 GMT

This post turned out to be a bit long, but please read it if you
think you might help me correct starting problems on my FJ.
(Yes, I know - the FJ never has any mechanical problems, so it is
probably just me :-)

Whenever my mechanical ineptitude has had me stranded over a
problem with the FJ in the past, I have leaned heavily on Chuck
Rogers as an FJ guru. However, to keep from swamping Chuck with
all my nagging, I thought Id try out the rest of you as well. Idont 
think that what I describe in the following necessarily is
an FJ-specific problem, so input will be appreciated from all
quarters.

In short: I have an 85 Yamaha FJ 1100 with 50000 km on the clock
(31000 miles), and the bike has become _damned_ hard to start!!
It wasnt like this in the spring - the problem appeared just
before we left for our honeymoon on the bike, and has persisted
ever since. (In fact, it wouldnt start on the day we left on our
4000-mile trip - we _just_ managed to push-start it...)

Symptoms description: The battery and starter cranks the engine
round just fine, but it refuses to ignite. Usually I am able to
get it going after about 3-4 tries on full choke (it has always
wanted choke to start) - unless it has been raining (humid air)
or the temperature is low - then it is almost impossible to
start. Jump-starting from my (non-running!) cages battery
usually does the trick, but it needs several tries then also.
(The battery in the bike is not at fault, but it will go dead
before the bike will start in many cases...) Rolling down-hill
also helps (if the hill is long enough - one day I had to push it
back _up_ again to try anew <groan!>.) The key point seems to be
that the engine needs to be cranked over for a much longer period
(about 30-40 seconds ?) than the battery or a short hill is able
to do, in order to start. During the cranking-over it often
backfires as well. 

Ive tried varying the choke settings, but it does not seem to be
part of the problem. While holding in the starter button, it also
seems to need a good twist of the throttle to finally get going
with a scream - if at all! When it is hot, it sometimes idles
very well - but often has this hesitant feel, i.e. varying RPM
and even stalls when idling after long runs (really warm engine).
One day in heavy rain, it even stalled after a 200 km trip when I
pulled in the clutch to coast to a stop. It worked very well
(just a few hesitant starts) on our trip through Europe, but then
the weather was nice and warm all the time. The problems are by
far most pronounced in the rain. Sometimes (also happens in the
dry) it is very hard to start it again 30 seconds after
stopping it - even when its thoroughly warm.

Id had the carbs synchronized at a shop just before the problems
started, so that ought not to be the problem (though you never
know.. :-(  I went down on the left side just before our long
trip (about the time when the troubles started) (Details coming
up in the trip report...), and I first thought that the timing
mechanism which is on this side might be damaged, but there
doesnt even seem to be a scratch on the timing cover (the hard-
bags took most of the impact...) Earlier this year, I had to re-
thread two of the spark plug holes, and I thought that maybe I
had created a blow-by route where water could enter, etc.
Inspection of the plugs reveals that all four look roughly the
same, so this does not seem to be the problem either. The plugs
were all fairly new (about 500 km?) and I changed the two I
suspected, without alleviating the problem. The air-filter is not
_that_ dirty, and anyway, it was almost new when the troubles
started showing up.

I am presently at a loss as to what the cause may be, but I
really want to get the problem fixed. It is depriving me of a
_lot_ of riding time - as the autumn is invariably very wet
here... :-(  Id appreciate any input you might be able to give
me - might it be the carbs? Something knocked loose or out of
position when I went down? (Remeber, it has run more than 4000
miles since...) I know next to nothing about the carbs, so Im
hesitant to dig into them before I really have to... I am
equally hesitant about taking it to the shop, as it seems to me
that this is a problem that a mechanic might easily fiddle about
with for (expensive) hours without necessarily finding a clear
cause. The shop is my _last_ resort.

Please post or e-mail as you see fit, but please help if you can -
Im getting a bit desperate...

Roar Larsen           DoD# 463
Trondheim, Norway    85 FJ 1100
Newsgroups: rec.motorcycles