Melatv

This is a chart of HP

Make/size Horsepower Lowest ratio (final:1)
The numbers after the HP is the gear ratio

Recon 250 15.5 HP 36.8
300 Fourtrax (after 1988) 16.5 HP 55.0
300 Fourtrax (1988) 18 HP 55.0
350 Rancher 21 HP 54.1
350 Foreman 24.5 HP 57.2
400 Foreman 21 HP 56.9
420 Rancher FM/TM 26.5 HP 46.5
420 Rancher AT (IRS) 27 HP 38.8
450 Foreman 24 HP 56.9
500 Rubicon 33.5 HP 58.6
500 Foreman 27 HP 51.0
500 Foreman (FI) 28 HP 53.4
650 Rincon 35.5 HP 17.7
680 Rincon 38.5 HP 17.7
 

420 Vs 450 HP

Hi @Kyle9076 I would say it's the capacitor for the pull start -- just unplug it -- tape it up good and plug it back together

Hi @Mach 1: Just blow any dirt out of the connectors and put some dielectric grease around the edges of the connectors (NOT ON THE PINS) 

@Mach 1  just info -- The CKP (crankshaft position sensor) send a 0.7 VAC (using PVA to test) to the PCM (ECM)  -- then the PCM send a pulse to G/Y wire on the Ign. Coil to only pulse it to ground to fire the spark plug. Now with the PCM (ECM) being bad – which was holding the ground on the Ign. Coil (G/Y) wire for ever causing it heat up and damage it. That G/Y wire should away read infinity when not running the atv.

14 hours ago, jeepwm69 said:

It was the ECU.  Got a used one from PSN today and it fired right up. 
 

Gotta get everything put back together and get it out of the yard. 

@jeepwm69 -- I like your way you doing things -- stick with it -- try and try -- ending up solving the problem. 

Hi -- The green/yellow should read infinity -- that wire is pulled to ground by the PCM  --  unplug the Gray 33P connector from the PCM -- unplug the Green/yellow wire on the coil and check that wire for continuity of that wire to ground -- it should read infinity -- if it does the PCM is at fault. 

HI @Green Bay Mike -- are touching the gas lever when starting -- if so don't

What is cause of the gouges on the fly wheel ? must be loose metal some where

HI @retro & @jeepwm69 I would un tape everything around that solder connector -- make everything right and try it. If still a problem then ECM or other things are the problem. The harness is a good deal if the person is willing to buy it first without cost to you.

Hi -- the wires with just the insulation covering just chew off -- use Permatex Liquid Electrical Tape --

 I don't like using those heat shrink tubes with solder in them -- because the wires have to be perfectly clean -- solder the connections tape them good -or use crimped connectors and liquid tape the ends.

I see chewed wires there and other things that would cause the problem -- @retro good to find time to help out.

11 hours ago, jeepwm69 said:

 Everything else plugged in or ?

Yes

On 3/11/2024 at 7:38 PM, jeepwm69 said:

No voltage at all at the coil with the gray plug disconnected on the ECU.

Do this again and let me know

Okay

Unplug the green connector (14pin)  going to the display meter --see if voltage goes up

With black meter lead on neg of battery -- check the voltage on each little gray dot on top of ign. fuse

Can stick a pin or something sharp into the Bl/R wire at the fuse block to take a reading

Okay will look for another spot

Could you check the voltage on the BL/R wire on the fuel injector

Okay you are dropping the voltage someplace else -- I will check some other points for you

Check this -- unplug the ign. switch -- you said there were 2 red wires -- do this use the black wire on the harness side of the ign. switch and jumper it to one of the red wires on harness -- then check for 12 volts on the ign. coil  -- if no 12 volts jumper the black to other red and check coil again.

Yes

@jeepwm69 remove the jumper and measure the voltage on the ign. coil -- if it's low you may have a problem with the ign. fuse holder 

Take a wire and place it in along side the Bl/R of the ign coil to the positive of battery -- check for 12 volts on the unplugged gray connector Bl/R wire 

Check the Ign fuse