Polaris TX Mod Project

This has been a fun project.

I took a 1980 TX 340 chassis and did just a few "Mods"

The goal is to have a fun vintage ride, that I can just pull the cord and go and to have handwarmers, and not need to premix the fuel.

I also wanted to keep the "vintage" look.

I hope this accomplishes my goals.

The specifications

1980 TX340 Chassis

1996 488 Fanner engine/clutches/wiring

1983 Polaris Indy Skid

1 inch Camoplast 121 inch track.

Custom exhaust pipe, combination 500 Indy liquid/TX pipe

1996 Indy Handlebars and wiring harness

1979 TX Hood

This is what it looked like when it was dropped off.  Extremely impressive, I know!

OK, only a face a truly sick person could love!

A picture at Live On Ski's in International Falls.

We put about 200 miles on it there!

Now for the build.

Another picture as I received it.


I first gutted the engine, clutches, wiring, etc.

Some cleaning done.

Part of the plan was to add hand warmers!

The only change needed was to move the steering arm on the handlebars.

Notice the difference.

The original weld ground down to allow it to be repositioned to work with the TX chassis.

Welded and painted

In place in the chassis.

From a riders point of view

The engine being fitted.

Clutches being lined up.  Due to using the newer clutches I had to move the engine to the right (mag side) about 1 inch.

The 488 required using a 440 engine mount plate.  The 340 (small block) uses a different plate than the 440 (fuji large block)

I ended up not using the electric start because the ring gear was giving me clearance issues.

More of the engine being installed

I ran into clearance issues with the air box.  I tried combining the 488 box, and the 340 box, but it did not work out.  I am currently running filters.

Still with the stock exhaust in place

Exhaust Pipe build

The stock 488 pipe limits the RPM's to 7000. 

I wanted to pick the RPM's up a little and it was recommended to use a 500 Liquid pipe which will allow around 8000 RPM's.

The trouble is that the 500 pipe didn't fit the chassis, so the remanufacturing began!

The stock 500 pipe.

The pipes compared.  The TX pipe is on top, the bottom is the 500 pipe.

The 500 pipe being cut up. 

The TX pipe

The pipe being combined

The pipe continued

I also ended up slicing the pipe at the elbow near the Y pipe and tightening up the angle slightly to facilitate a better fit.

I do not have any pictures of this.

The pipe in place.

The total length of the stock 500 pipe was maintained.

The Seat recovered

Installing the 1983 Indy Skid

The skid with new shocks, wheels, Hyfax, bearings, and torsion springs.

Ready to install

The skid had to be relocated forward to install this skid along with the rubber track.

The total distance between the bolts needs to be 25 inches. I verified this with a factory installation.

 I reinforced the new holes with aluminum plates that I riveted onto the chassis because it is no longer bolted through the steel brackets..

The front hole was moved forward about 3 inches.

The rear hole was moved forward about 2 inches.

The track drivers were also used from the 83 Indy to change from a cleated track to a rubber track.

With the skid installed, prior to the aluminum reinforcements.

The 488 uses twin 34 mm Mikuni's.  Currently I have changed the stock 230 jets, to 260. 

Both clutches also have been revamped.  The stock red spring was first changed to a stock gold spring to raise clutch engagement.

This helped, but I then installed a white Erlandson spring.  This has a 125/280 raiting compared to the red spring at 120/245.

I now have engagement at about 3700 RPM's versus 3000 when I started.

The secondary helix was changed from a 36 to a 34.  This helped to increase the RPM's to about 7700.

Some more fine tuning will be done, and possibly some 38 mm carburetors.

Another picture

So far, no painting has been done, I may leave it as is, or it may get a facelift over the summer. 

HotRod black keeps coming to mind!