Polaris Trail Boss 330 2003MY Hard To Start
 

I am having a problem staring my polaris trail boss 330.
Replaced the fuel pump, all fuel lines and installed a brand new carburetor. Still hard to start. I use starting fluid and it spits and backfires. If I open the throttle sometimes it starts. Once it is warm I turn it off and it is very hard to start again. Crazy thing is that once it is running it is fine. Very difficult to start! I am thinking this May be an electrical issue now. Has anyone experienced these hard to start symptoms on a polaris trail boss 330? Thank you.

Rather than throwing anymore parts at it get this cheap 5 buck manual that has good trouble shooting checks and tests.2003 Polaris Trail Boss 330 Service Manual PDF Download This is one of the tests in the manual..

IGNITION SYSTEM TESTING
Whenever troubleshooting an electrical problem you should first check all terminal connections to be sure they
are clean and tight. Also be sure that colorsmatch when wires are connected. Use the following pages as a guide
for troubleshooting. The resistance values are also given on the specification pages.
Condition: No Spark or intermittent spark
Disconnect the black wire at the CDI module to
isolate the ignition from the kill system, but
verify the CDI has a good ground (brown) for
operation.
Does it have spark?
-Test the ignition switch, engine stop
switch, and speed limiter circuit for
shorts to ground.
-Check connectors for moisture,
wire color matching or corrosion.
Disconnect the pulse (trigger) coil connector from
the CDI module. Measure the resistance of the
trigger coil (520 ohms). Refer to the exploded view on
Page 10.9 or the wiring schematic for meter connections
and specifications. Compare results to
the specifications on the exploded views.
Is it within specification?
Inspect connectors, wiring and
grounds to the component in question.
Replace the component if a
wiring problem cannot be found.
Check coil ground connection between engine and coil
mount using an ohmmeter. The coil mount should
have good continuity to ground on the engine (0-.2 ohms.
Verify 12 Volt DC power is present on the red wire to CDI. Replace Spark Plug.
Disconnect and check the secondary coil. Resistance
values should be:
Primary Side - Primary Wire Tab to Ground
(on coil mount or engine): .3 to .5 Ohms
Secondary Side High Tension Wire to engine
ground- Cap installed - 11,300 ohms
Cap removed - 6300 ohms
Are these values within specs?
No Replace the ignition coil.
If all of the above tests are within specifications, and all grounds, connections, and wire color coding
have been inspected, perform voltage output tests on following page or replace the CDI module.

This model also has the troublesome ecm module that can cause problems. Best to eliminate all other items before replacing this module. Item #18.

Polaris won't start update
 

Thank you for the tip on the service manual. I purchased yesterday. Also started trouble shooting the electrical starting with the ignition coil. Noticed when I pulled the plug wire it was broken. That is the contact broke off on the plug. So I pulled the coil and had the local cycle shop test it. Coil tested fine so I paid $6 for a NGK aftermarket plug that screws right into the coil wire. I will install when I get home. Update pending the coil retrofit. I believe the hard start and intermittent start performance may be consistent with poor intermittent contact at the coil wire to spark plug interface.

Polaris trail boss won't start
 

We'll I installed the coil with new cap and no spark. Dealer tested coil ok and I measured primary side at 0.6 ohms and secondary side with cap is 11K ohm. Ran through the ignition system test and everything checks ok. Pulse trigger coil is at 485 ohm. Coil to engine resistance is 0.2 ohm.
Trouble shooting in manual says if all the above items are in spec then perform voltage output tests or replace the CDI. I frankly don't know how to do the voltage out put tests. Should I replace the CDI now or figure out how to do the voltage output tests?

2003 Polaris Trail Boss Wont Start
 

Old Polaris Tech. Please let me know any further feedback. I appreciate the help and support. My diagnosis minus the voltage output tests points to the CDI per the service manual.

Believe you need a peak voltage adapter or a peak meter to be able to perform this last test.My suspicion is still the cdi module as that's the purpose of all the other tests you've done,to eliminate them as the problem area which would leave the cdi as the culprit.

Okay thank you. I found a source for the CDI module. Cost is about $190.00. I will order one and see if it works. Thanks for the help. I will let you know the outcome in the next couple of days. Thank you.

Polaris 2003 Trail Boss Wont Start
 

RegulatorRectifier has a CDI for this model Polaris for 189.99. Comes with 1 year warranty but no returns allowed.

Most places won't allow returns on any electrical part whether you open the package or not. It's been that way for years.That's why you need to be fairly sure when you order parts.

Trail Boss 330 Wont Start No Spark
 

Well I installed the new CDI and still no spark. I even disconnected the throttle ETC connector thinking that might be the cause. No luck. I followed the trouble shooting flow chart and everything measures okay - ignition coil resistance on primary and secondary good. Pulse trigger coil resistance is 480 ohm - good. Checked coil ground to engine good. Replaced CDI. I even measured the stator coils at the voltage regulator and they all measure 0.7ohms each. I know the stop switch is okay because I disconnected the black wire at the CDI and still no spark.
Only 2 Things I have not Checked:
1-I have not checked the ignition switch. Is it possible the ignition switch can crank the motor and not allow spark?
2- Service manual claims a sheared flywheel key or loose flywheel could be the root cause. Seems like a long shot.


Any ideas on what I might have missed?