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We are parked on
North Branch
for a breather after a BBQ
up in the
NISBET FOREST
on this ride.
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'16 YAMAHA Triple
SXT
700
PROJECT SLED
-
WE
INSTALL SOME "S"
FOR SPORT ON OUR
"XT"!!
SXT
!
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RECONDITION
A
DESCENT
RUNNING SLED INTO A GOOD BACK COUNTRY TOUR SLED.
-
ADJUST
AND/OR REPLACE THE
COMPONENTS THAT HAVE BEEN POORLY ADJUSTED OR JUST ABUSED.
-
END
UP WITH A SLED THAT HAS EXTREMELY RESPONSIVE HANDLING
AND CAPABLE.
This 700 triple
is equipped with a nice 1.5" track. This sled's reasonably short
track and all temperature responsive 115 HP mill make it a great trail breaker thru the tight NISBET FOREST trails.
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A Parked on a small
Un-named
remote
winter platform in the Nisbet Forest,
good test ride that is revealing an over rev.
A clutch weight change is required to make the engine shift at
8200,
85-8600 is out of the power band with stock cylinders and pipe
18-01V. |
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Down the road with the sled running great I added different skis,
suspension components and skid plate for cosmetic reasons.
Who said we don't have anything Yellow?
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We run her hard
for lots of miles after the carburetor reset
and top end freshen up.
16-09V |
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#1 THE ENGINE RAN.
#2 ON THE ADVICE OF THE PREVIOUS OWNER I TORE THE
TOP END DOWN.
#3 WE PUT HER TO
THE TEST and RUN HER W.O.T. for MILES ON END.
#4 REAR SUSPENSION SHOCK and COUPLER BUSHING SERVICE.
#5 UPGRADE
the TRACK.
#6 OK
TIME FOR THE OEM YAMAHA CLUTCH, and WELL, WE FEEL SHE IS
"Reverse Worthy" SO IN GOES THE REVERSE GEAR BOX......HOLDING MY
BREATH. |
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#1
THE ENGINE RAN Fall 2015/Winter 2016
When I bought this
sled it fired up and ran. The owner said it needed a set of
pistons that something went wrong on its last ride a number of
years ago. I took some time to analyze it. The engine did sound
like it was missing...but it felt good to pull over on the rope.
I got it home and unplugged the TORs system safety plug and
fired her up, I then proceeded to cut a couple uballs on the ice
with her revving right out and she sounded pretty good! Over the
next month or so, there was a few times it started up good,
cold...then it was hard to start some plugs looking wet some
not. Then it wouldn't start....the plugs were dry, dropping in
some gas it would run again? The engine would be backfiring lean
and smelt like it was running really rich...all at the same
time!!! Could the fuel pump be leaking fuel thru the diaphragm
to the #2 cylinder wetting it down then alternately completely
draining the fuel system out into the crankcase under #2
cylinder? The lack of fuel was making the engine
impossible to start unless fuel was injected manually into one
of the cylinders. A long shot...I have no memory of having to
change a fuel pump on one of our Yamaha's ever....the fuel pump
change was drastic. The sled now starts and runs reliably. The
lean pops were gone but it still felt really rich. The sled was
equipped with an temperature and elevation sensitive fuel
system. After a short run up at one of the vintage oval races I
pulled the carbs apart to see what we have. |
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a) AS
PURCHASED
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Examining the snaps from KIJIJI carefully it looks like
the track had been changed...the things you notice after
the fact. LOL!! |
b) A
PRELIMINARY PLUG CHECK!
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It appears the the previous
owner had a hotter BR8 spark plug in the #1 cylinder. It
has a tip extended deeper into the combustion chamber...
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...where it
would run hotter. I am guessing they had fowling
problems with #1. What else will we find.
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c) OVER and
OVER, I START THIS SLED OUT IN THE COLD
I start the engine in
the cold looking for consistency...there isn't any! I was going
into the carbs for sure no matter what, but I change the fuel
pump first trying to solve a very unusual lean/rich starting
problem that changes the longer the sled sits, going from
flooded rich, to starting not bad but backfiring to a sled that
will not start at all unless fuel is manually injected thru the
air box. |
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THE VERDICT
On a whim after experiencing
the bizarre starting characteristics...it turns out
changing the fuel pump was the ticket. It had been
bleeding fuel into the center pulse line lower crankcase
creating all the fickle fun at start up.
Changing the fuel pump
cured this bizarre condition, I assume fuel was running past the
"pumping" diagram thru the "pulse" hose into the center engine
case section below the #2 piston. That is why one cylinder would
be flooded wet and the others dry in a series of different
degrees and stages evident over "various" amounts of
time. The common thread was pulse line location and accompanying
unexplainably a wet cylinder. This must have been driving the
previous owner nuts. |
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I Look the carbs over and check the choke
adjustment on all 3 carbs. |
d) A QUICK
TEST RIDE
16-05
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I
FINALLY DIVE INTO THE CARBS
The main jets
right across are richer than I would ever run.
Very surprising I find that the
fuel mixture idle screws that provide
 maybe
up to 15% of the total fuel to the engine are
adjusted unlike anything I have ever seen. The fuel
screws were out richer than any spec mentioned. Also all
three carbs had been set with different screw settings
on each carb. The floats were OK.
The fuel screw for #1 was out like
3.5 turns instead of say 2 turns, #2 was out 2.5 turns
rich and #3 cylinder carbs fuel screw was out 2.0 turns
right on spec.
Later when I pulled the head this is what I found for
piston wash.
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Massive piston wash, richest fuel screw setting and
richest main jet. |
Still a little rich on the
fuel screw, and a little rich on the mains for my
liking, wash not real distinctive, remember this is the
cylinder affected by the fuel draining from the fuel
pump into the crankcase. |
The leanest cylinder in
purchased form, fuel screw on spec (for my main jet
preference) and yes wash indicates she is overall plenty
rich. My set up will minimize wash a small amount. |
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#2 ON THE ADVICE OF THE PREVIOUS OWNER I TORE THE
TOP END DOWN Winter 2016
Time to pull her
apart, the Odometer shows 7675KMs and it was disclosed that the
Odometer had stopped some time ago. The owner had bought the
sled told me he added the 1.5" track, new clutch and
several other performance parts including an atmospheric fuel
adjustment system, performance reed valves and reed stuffers. |
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The engine sounds good but the mileage
really is unknown. |
So off with her head!! |
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Aside from the crazy
piston wash...a result of real out of spec fuel screw
adjustments
THE ENGINE is
VERY NICE.
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I am looking at
the piston wash once the head is off.
Man what kind of wash is that?
The cylinders exhibit virtually no physically detectable
wear. NICE! |
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They honed up like new. |
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The bottom end cleaned up ready for the top end. |
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The gaskets are all hightacked.
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New pistons hanging on the rods. |
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And yes just like the
kids on the bus...they go up and down! |
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#3
WE PUT HER TO THE TEST and
RUN HER W.O.T. for MILES ON END
A On a very warm
spring day we go for our last ride of the year. It is time to
run this sled hard all day. Like Smokey Yunick would say "Shake
her up in a bag" and lets see what we've got!! Some times
you end up with a Bag of "- - - t", you don't know until you put
her to work.....I know just the way to put her to work
alright...Fox N Hounds with the boys across
Saskatchewan! |
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I INSTALL A NEW
SET OF PLUGS FOR THE A REAL RUN IN THE NISBET
RUNNING NICE IT
IS TIME TO PUT HER TO THE REAL TEST
16-09
V
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After our 125Km run I do
a plug check.
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#4 REAR SUSPENSION SHOCK and COUPLER BUSHING
SERVICE Summer 2017 |
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a) CHAINCASE
BEARING
SERVICE
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The chain case drive bearings get seals pulled and
greased as well. |
Reinstalling the seal. |
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Then the snap ring, |
Once A tug on the snap ring
tells us it is seated. |
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The amount of side slop in the
chain used to help determine how worn it is. I will
examine this more closely in the near future. |
The chain case had a 23 tooth
sprocket over a 40 Tooth for a 1.739 ratio.
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Lower bearing reinstalled. |
I built a dam of grease in the
speedo angel drive housing to contain some light oil. |
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b) SHOCK and
COUPLER BUSHINGS
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The main skid frame shock bushings were dry and worn
badly. |
The transfer rods were equally dry and worn. A
replacement bushing is in the pic for comparison. |
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The upper track idlers are cannot be
changed or serviced with out dropping out the back
section of suspension...so this is the time. Both
bearings were rough. |
I found a couple bearings on the shelf,
one had visibly a good amount of grease, I was
accustomed to finding grease in "this BLUE BRAND". |
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There is barely visible amount of grease in this "black
bearing". |
Yup "BLUE" has a generous amount of
grease. It is rare to see this. I packed them both
anyways.
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The skid is ready to go in. |
Where the rubber meets the road, so to
speak! |
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#5 UPGRADE
the TRACK
Summer 2017
Part of the
puzzle is upgrading the track for our Nisbet cross country
riding. A lot of opinions is out there but we want a maximum
traction in loose snow and yet something that can be driven on a
groomed trail from time to time....maybe never...but if it
happens! . Also the more snow moving and being carried by the
track the slower the sled will be. This is just plain physics,
we have found that a 121 x 15 x 1.5 is great on our 115HP 700's
and that a 121 x 15 x 1.25 is great on our 100HP 600's.
A few years
earlier I had bought a
1999 V-MAX 700 that was being parted
because aside "the engine", the "track" and 3 of the 4 "shocks", there
was not a single other straight or not cross threaded part on
her!
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a) TRACK AND
DRIVE AXEL CHANGE
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The track as purchased was a great 1.5" track but had
been subjected to some unreal abuse just prior to the
sled changing hands.
The 121 x 1.5 that the sled came with is
hard to look at. There were a lot of broken and missing
treads. |
I say this because a lot of paddles or treads
appeared to have been "just freshly" broken off....in fact
running the sled on a test stand at speed the very first
time...resulted in 3 or 4 treads flinging off one was 6 to 8"
wide, ouch don't stand behind this one
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b) NECESSARY TRACK
CHANGE
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This is the replacement track, a nice 121 x 15 x 1.5"
Polaris/Camoplast
#5411740 |
Having purchased
and salvaged a '99
XT
700 a
few years earlier,
I pulled this track off the
shelf,
-perfect track
-perfect place to use it and
-perfect timing. |
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OUT WITH THE
OLD
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The main rear skid frame shock is dry and free of
corrosion. The
speedometer did not work on this sled. The original
front drive shaft had a speedo cable broken off in it. I
broke a few tools attempting to extract the debris. |
The track
needed changing and the bearings needed to be packed
with grease so hell lets just do it all! My spare drive
shaft had center drivers only so I pressed the original
outside drive sprockets onto the replacement. |
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FRONT DRIVE
INSTALL
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I have changed and installed the front drive. |
It The LT side lower drive bearing
goes back on full of grease. |
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The axel is in thru the tunnel into the chaincase. |
The LT side lower
drive bearing needs the allen screw locked to the shaft. |
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#6
OK TIME FOR THE OEM YAMAHA CLUTCH, and WELL, WE FEEL SHE IS
"Reverse Worthy" SO IN GOES THE REVERSE GEAR BOX......HOLDING MY BREATH
Fall 2017
A On a very warm
spring day we go for our last ride of the year. It is time to
run this sled one more time!
 Like Smokey Yunick would say "Shake
her up in a bag" and lets see what we've got!! Sure don't
want to be this guy! |
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A) I EXCHANGE THE
COMET FOR AN OEM CLUTCH
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 This
was interesting...laying the Yamaha clutch, clutch
alignment tool on the SX 700 I found this large offset
to the secondary exists with the Comet clutch
installation. What happens when I install the OEM Yamaha
clutch will be interesting. |
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I
knew this before I rode the sled in the SPRING of 2016.
For that reason I had a used "disposable" belt on the
sled. I do not have a "Comet" clutch alignment tool so
who's to say if this was right or wrong. There was a
hell of a pile of blown belt fragments under the
engine....so no way am I putting a brand new belt on a
"potential" belt eating monster! |
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Well I did not photo graph it but after installing the
OEM clutch the alignment was still a way off just like
the Comet alignment! I can only guess that "who ever"
installed the Comet believed that the correct alignment
was a pretty serious offset. I have no idea why this
would be right. Is this why there was a pile of blown
belts in the chassis? Once this was discovered we move
the engine back as the photo shows see inset. |
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b) OUR BABY GETS THE
REVERSE TREATMENT!
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