[Meech86]

Hello everyone,

For a few seasons now, me and a buddy have been trying to get his 97 Polaris ultra (680) running well without success. It's the same issue every year regardless of what we do to it. Sometimes the sled runs great and doesn't run rich, and then when you go to use it later on, it runs really rich and bogs right as you try to take off and it doesn't clear.

Things that have been done:

Carburetors have been gone trough and cleaned
Seat and needle are sealing after performing a leak test
Carburetor boots are new from last year
Plugs are brand new
Exhaust manifold had a pinhole leak which was welded shut and all new gaskets throughout the system
I did a full tear down of the motor and changed the seals and all gaskets, the motor is air tight as I did a leak down test after the rebuild.
All three jugs have a compression of 125 PSI on a cold engine
Gas tank line has been cleared and all new lines have been installed + a new filter

The only thing I noticed was that the choke plungers were indented but I though maybe this was normal since they have been in there for quite a while. I would need to verify them a little closer to see if they have stiffened up and causing them not to completely seat at times.

Is there anyway I can test when the plungers are shut to make sure they're sealing all around?

This has been the most inconsistent motor I have ever worked on.

Thank you for any insight.

 

[tgsmartcows]

Hello everyone,

For a few seasons now, me and a buddy have been trying to get his 97 Polaris ultra (680) running well without success. It's the same issue every year regardless of what we do to it. Sometimes the sled runs great and doesn't run rich, and then when you go to use it later on, it runs really rich and bogs right as you try to take off and it doesn't clear.

Things that have been done:

Carburetors have been gone trough and cleaned
Seat and needle are sealing after performing a leak test
Carburetor boots are new from last year
Plugs are brand new
Exhaust manifold had a pinhole leak which was welded shut and all new gaskets throughout the system
I did a full tear down of the motor and changed the seals and all gaskets, the motor is air tight as I did a leak down test after the rebuild.
All three jugs have a compression of 125 PSI on a cold engine
Gas tank line has been cleared and all new lines have been installed + a new filter

The only thing I noticed was that the choke plungers were indented but I though maybe this was normal since they have been in there for quite a while. I would need to verify them a little closer to see if they have stiffened up and causing them not to completely seat at times.

Is there anyway I can test when the plungers are shut to make sure they're sealing all around?

This has been the most inconsistent motor I have ever worked on.

Thank you for any insight.

You didn't mention checking enrichment cable slack. With no slack the cables will hold the plungers off the seat. Common find for me on old sleds. Choke cables replaced without due diligence on adjustment. Service manual clearly describes the procedure. Please check throttle cables too. Number one source of carb sync issues.

 

[Meech86]

You didn't mention checking enrichment cable slack. With no slack the cables will hold the plungers off the seat. Common find for me on old sleds. Choke cables replaced without due diligence on adjustment. Service manual clearly describes the procedure. Please check throttle cables too. Number one source of carb sync issues.

Thank you for your response, we were able to pin point the cause of the issue last weekend. It turns out that the block that splits the the cable from 1 to 3 was getting caught up when actuating the choke lever. The block would slide out of it's place and catch on the way back in which would keep the plungers up...

After fixing that issue, the motor had zero issues for the remainder of the weekend and my buddy got to ride his machine!