1993 Polaris Indy 500 EFI - Boggy on the low end

[sean.m...@gmail.com]

We have a Polaris Indy 500 EFI, it is very boggy at the low end. If
you juice the throttle hard from 2000 rpm it will bog and stick at
about 3800 RPM and continue to flood / bogg. If you back off the
throttle, to about 2000 again and bring back up to 4000 it will
eventually clear then the clutch will kick in and you'll be on your
way. However, under 40mph if you hit the throttle it will continue to
bogg unless you carefully feather the throttle and bring it back up.
Between 45 and 70 it runs well, but at about 70 it won't go any
faster.

We have a new battery in it that is fully charged, we put brand new
fuel & oil in this weekend; and also pulled out the airfilter
temporarily to ensure that wasn't the issue. Another odd symptom is
that on a 40 mile trail ride (averaging 25 mph) it burned about 5
gallons of fuel. As far as I can see there isn't any fuel leaks. Any
thoughts around what the problem may be?

Thanks in advance!

[David Courtney]

My guess would be a bad sensor... possibly throttle position sensor.
The first thing to do would be to check for any trouble codes in the
computer, click here to find out how:
http://groups.google.com/groups/search?q=codes+polaris+efi+group%3Arec.sport.snowmobiles

<sean.m...@gmail.com> wrote in message
news:7a8325d6-be57-4780...@e10g2000prf.googlegroups.com...

[D Ward]

Could be a clutching problem. When was the last time the clutches were
serviced?

"David Courtney" <adv...@powercom.net> wrote in message
news:VYidnQBo-pA__R_a...@enscoop.com...

[David Courtney]

It's "bogging" before the clutch engages though.

"D Ward" <d_w...@telus.net> wrote in message
news:L7Dgj.42$vp3.31@edtnps90...

[Repairman]

Sounds like bad clutching.
Weak / broken secondary spring will cause sled to seem to start in "second"
gear. Motor loads up trying to pull through the high load. That's just one
example of clutch issues.

Worn belts , wrong offset, incorrect center distance, broken motor mounts as
well as binding or worn driven clutch parts will cause performance issues.
Lets not forget any binding in the track either.
A motor problem will not let the sled get up to 70. Top speed on that
vintage 500 is upper 80's anyway.
Clutch problems will not allow the motor to get up to it's power band
quickly so it bogs down and lugs until the sled has enough ground speed to
allow the motor to get close to it's power band. Most 2 stroke sled motors
aren't making any HP until they are over 4500 - 5000 rpm. Correct clutching
gets the motor up to it's peak 8k rpm as soon as possible and holds it there
when you drop the hammer.

"David Courtney" <adv...@powercom.net> wrote in message

news:M_idnVL9Fd4FDx7a...@enscoop.com...

[David Courtney]

It can't be the clutch... his bog is occurring before the clutch even
engages:

"If you back off the throttle, to about 2000 again and bring back up to 4000
it will eventually clear then the clutch will kick in and you'll be on your
way."

"Repairman" <repai...@embarqmail.com> wrote in message
news:fm6pcl$tvf$1...@aioe.org...

[Repairman]

By the statement bogs and sticks at 3800 when hammered means a low
engagement, bring it up again, probably slowly but he doesn't say, would
allow it to pull through the low engagement.
I'm thinking weak springs in the clutch's or binding up, drive weak would
let the sheaves in too hard too low in power band causing a bog.
Weak in the driven would let sheaves open too soon causing the same.
Under 40 mph bog means no back shifting to get the revs up.
Not enough info as we don't know if it's pulling up to 8k rpm once it's
going.

Let's see if more info follows, I'm off to do a snow dance in the
Adirondacks so I'll be 'puter free for a few days if my moves
work...........

cut 'n paste below.....

If you juice the throttle hard from 2000 rpm it will bog and stick at
about 3800 RPM and continue to flood / bogg. If you back off the
throttle, to about 2000 again and bring back up to 4000 it will
eventually clear then the clutch will kick in and you'll be on your
way. However, under 40mph if you hit the throttle it will continue to
bogg unless you carefully feather the throttle and bring it back up.

"David Courtney" <adv...@powercom.net> wrote in message
news:I7-dnYeoiLXP4xra...@enscoop.com...

[sean.m...@gmail.com]

Hey guys,
Thanks for all the great discussion. The clutch doesn't kick in
unless it clears the 4500 mark (possibly a bit higher, I can't
remember off hand) at 3800 it just bogs and the belt is not engaged
(this is right after starting it). The other symptom is that in 40
miles I burned about 4-5 gallons of fuel; which seems pretty high to
me :)

It does not get up to 8000RPM when opened up.

[David Courtney]

It sounds like you have a bad sensor or bad sensor wire, like I said
before... I would start with trying to retrieve any trouble codes so you
know what sensor to start with.
Once the computer realizes that it's not getting good information from
one of the sensors... it will go into a "limp home" mode where it pours in a
bunch of extra fuel to keep you from seizing the motor while you "limp
home".
With the engine running... look for a flashing LED on the computer, near
the wiring harness plug.
It should be flashing a code... some long flashes followed by short
flashes.

<sean.m...@gmail.com> wrote in message
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