Dear fellow GTS owners, I would appreciate any input on the
following:
Being a satisfied GTS owner myself, I recently helped my fellow
riding buddy Tom acquire his own 1993 GTS since he liked my bike
so much. His bike had low mileage and we performed all the "prep"
work such as changing the oil/ air filters, coolant, plugs, etc.
We proceeded to do a compression test on the bike which showed
160 psi on all four cylinders which seemed normal. The bike ran
fine this entire previous riding season. Later in the season,
Tommy and I were preparing for one last trip of the season. While
packing for the trip on the previous night, Tommy had
re-installed his battery which he had recharged as a precaution
and checked the oil which was fine the whole season and showed no
excessive consumption or burning. He then stated that he started
his bike as usual and quickly turned it off after a few seconds.
Well all seemd fine until the next morning when Tom's bike simply
would not start. It turned over and over but would not start. So
we had to cancel the trip.
The next day, we removed all the coweling to get to the plugs. We
did everything! "Replaced" the plugs, checked the spark, the oil
even replaced his CPU with mine. Nothing. So we re-checked the
compression on all 4 cylinders. Now the results here where very
confusing. Before the reading were 160 psi on all 4, now each
cyclinder was totally off and inconsistant!!. Cylinder #1 =
120psi, #2=110psi, #3=75psi!! and #4= 135psi. What the hell
happened?? I then checked the valve clearances and all were
within specs (both intake and exhaust) and the top of the engine
seemed to be getting oil. It didn't seem that the engine skipped
a tooth on the cam chain or anything like that. The throttle syns
were also in sync. I checked and rechecked the compression and
even did a leak down test. The results were the same...Confusing
with low psi!
During the previous whole season after about 4 thousand miles,
the bike ran great. It did not burn any oil, did not leak or
consume any coolant, did not over heat etc. So we reassembled the
bike and the bike did start. Where the plugs bad? Now the bike
starts fine, idles fine and seems to run fine and strong with no
valve tapping or anything. Does anyone have any explanations or
suggestions on why this was happening after only 4 thousand miles
on the bike ?? This next season, we will run the bike normally
and re-check the compression after several hundred miles or so.
However, I don't expect any changes.
