Polaris ATV Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
I have a 2005 polaris sportsman 500 ho I know nothing about it guy I bought it from said he drove it one day and the next it wouldn't crank when I got it home starter wouldn't engage found a brown wire melted that is the I'm guessing ground for the starter in the stator harness tied it back together but had no spark I have put new stator, pickup coil, coil, cdi box stator come with new harness of course but even the new wire when turning over has melted I also have only one spark when the key is turned on what could it possibly be somebody PLEASE HELP I'm lost
 

·
Premium Member
2008 800 ho efi, 2019 850 SP premium
Joined
·
5,304 Posts
Your question has now been logged into the queue and the next available forum member will answer you shortly. You will be given more advice than you could hope for.
 

·
Registered
Joined
·
12 Posts
It is possible that the quad could have a short somewhere in the circuit. Aside from arcing the most likely reason for a wire to melt would be that there is too much current rushing through. If you have a multimeter I would check resistance. Also what gauge is the wire? I believe it is 18 gauge, if so there should be no more then 16 Amps running through.
 

·
Premium Member
2008 800 ho efi, 2019 850 SP premium
Joined
·
5,304 Posts
Welcome to the forum

Your question has now been logged into the queue and the next available forum member will answer you shortly
 

·
Registered
Joined
·
11,903 Posts
The ground between the frame and the engine and frame has been lost and the starter motor is grounding through the small gauge control wiring ground wire. The correct ground is about a 6 gauge. #13 in the pic
150072
 

·
Registered
Joined
·
11 Posts
Discussion Starter #6
The ground between the frame and the engine and frame has been lost and the starter motor is grounding through the small gauge control wiring ground wire. The correct ground is about a 6 gauge. #13 in the pic
View attachment 150072
Thank you I haven't been able to find a diagram yet I made my own 10 gauge ground and now it spins I've I figured out the no spark traced it to a bad kill switch but it still won't run have spark and can spray starting fluid in carb but get nothing but a backfire every now and then have checked timing and and cam lobe everything is good key isn't sheared back fires out of exhaust and one time slightly through the carb I'm usually pretty swift with small engines but this has gotten me stumped
 

·
Registered
Joined
·
11,903 Posts
Try a new spark plug - a backfire from the exhaust during starting usually indicates a weak or late spark many times caused by a fouled (carbon coated) spark plug
 

·
Registered
Joined
·
11 Posts
Discussion Starter #8
Try a new spark plug - a backfire from the exhaust during starting usually indicates a weak or late spark many times caused by a fouled (carbon coated) spark plug
Spark Plug is brand new and clean the spark Is a good strong spark new coil cdi and trigger/pulse coil could I not possiblity have the new trigger coil set right it's got round holes so not a lot of adjustment can be made I just put it on and tightened it up I usually set coils with a business card and have never had a problem but since there isnt hardly any adjustment able to be made I didn't bother
 

·
Registered
Joined
·
11,903 Posts
If it has spark, the trigger coil is set fine - all the trigger coil does is tell the CDI box to fire the coil
 

·
Registered
Joined
·
117 Posts
If it has spark, the trigger coil is set fine - all the trigger coil does is tell the CDI box to fire the coil
Could he be having a issue with another wire that got fried when he lost the ground from the battery? Possibly the spark plug wire at this point corroded or damaged at either end? Assuming that he’s fixed the brown wire and isn’t missing a section further up the harness? Just trying to learn, think, and contribute where I can.
 

·
Registered
Joined
·
11,903 Posts
Could he be having a issue with another wire that got fried when he lost the ground from the battery? Possibly the spark plug wire at this point corroded or damaged at either end? Assuming that he’s fixed the brown wire and isn’t missing a section further up the harness? Just trying to learn, think, and contribute where I can.
Highly unlikely, but it's also likely he does not have the tools to accurately check the ignition system and ignition systems can be finicky - I have seen many NEW cheap Chinese POS Amazon stators, coils and CDI boxes bad right out of the box.

Since the ignition is DC powered, a lack of spark has to be determined by a process of elimination - first, is there 12v on the red wire at the CDI unit and no continuity to ground on the black wire.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #12
Highly unlikely, but it's also likely he does not have the tools to accurately check the ignition system and ignition systems can be finicky - I have seen many NEW cheap Chinese POS Amazon stators, coils and CDI boxes bad right out of the box.

Since the ignition is DC powered, a lack of spark has to be determined by a process of elimination - first, is there 12v on the red wire at the CDI unit and no continuity to ground on the black wire.
I do have a nice multi meeter test lights and so forth I did ohn my pickup coil when I first got it and it read 27 ohms is the reason for replacing it the other stuff I replaced is just bc I wanted to so I would have to later on being it has a rad relocate it's aggravating to get to everything else
 

·
Registered
Joined
·
11 Posts
Discussion Starter #13
Highly unlikely, but it's also likely he does not have the tools to accurately check the ignition system and ignition systems can be finicky - I have seen many NEW cheap Chinese POS Amazon stators, coils and CDI boxes bad right out of the box.

Since the ignition is DC powered, a lack of spark has to be determined by a process of elimination - first, is there 12v on the red wire at the CDI unit and no continuity to ground on the black wire.
I'm having trouble finding the specs and diagrams for everything
 

·
Registered
Joined
·
11 Posts
Discussion Starter #14
Could he be having a issue with another wire that got fried when he lost the ground from the battery? Possibly the spark plug wire at this point corroded or damaged at either end? Assuming that he’s fixed the brown wire and isn’t missing a section further up the harness? Just trying to learn, think, and contribute where I can.
Brown wire is fixed nothing else is burnt coil is brand new so plug wire is new
 

·
Registered
Joined
·
11 Posts
Discussion Starter #15
Highly unlikely, but it's also likely he does not have the tools to accurately check the ignition system and ignition systems can be finicky - I have seen many NEW cheap Chinese POS Amazon stators, coils and CDI boxes bad right out of the box.

Since the ignition is DC powered, a lack of spark has to be determined by a process of elimination - first, is there 12v on the red wire at the CDI unit and no continuity to ground on the black wire.
Do you think it could be valve lash as in exhaust valve not closing all the way guy I got it from said he checked lash idk if he adjusted anything though exhaust cam lobe looks good no compression coming back through carb timing is good
 

·
Registered
Joined
·
117 Posts
Do you think it could be valve lash as in exhaust valve not closing all the way guy I got it from said he checked lash idk if he adjusted anything though exhaust cam lobe looks good no compression coming back through carb timing is good
Just so i am clear and understand you correctly, “I have put new stator, pickup coil, coil, cdi box stator come with new harness of course but even the new wire when turning over has melted” then you installed a new black ground wire from the battery to the frame and the engine?, and repaired the brown ground wire that melted. You also checked the ohms on the new stator? You now have good spark but only get a backfire occasionally. Have you gone through the carb yet to ensure pilot and main jets are open. Are you getting fuel? Is petcock clear and functional? If you have good spark and compression, and you are getting an occasional pop with spray, I’d be investigating fuel at this point. Also I found a similar wiring schematic from one of @latebirds old posts, and the brown wire runs from the stator to the ground on the coil with a side stop grounding out on the engine block. I would replace that wire (with the appropriate color so you know if you ever need it again)

I’d be looking at fuel at this point. Provided you have ruled out compression, spark, and timing.... the last piece here is fuel. How long did the bike sit after he couldn’t get it to run? On top of that, what kind of crazy weird stuff did this guy do to attempt to seal up the carb? I flipped one a month ago where the guy basically said similar things to me, but he had “cleaned the carb” so I immediately looked at it and it was “fixed” with rtv and jb weld to keep it from leaking..... LoL. I changed the plug, starter, battery, and of course the carb. Viola it ran like a champ. People do some crazy homemade “fixes” and you really can’t trust them.

pic is from @latebird
150275
 

·
Registered
Joined
·
117 Posts
Just so i am clear and understand you correctly, “I have put new stator, pickup coil, coil, cdi box stator come with new harness of course but even the new wire when turning over has melted” then you installed a new black ground wire from the battery to the frame and the engine?, and repaired the brown ground wire that melted. You also checked the ohms on the new stator? You now have good spark but only get a backfire occasionally. Have you gone through the carb yet to ensure pilot and main jets are open. Are you getting fuel? Is petcock clear and functional? If you have good spark and compression, and you are getting an occasional pop with spray, I’d be investigating fuel at this point. Also I found a similar wiring schematic from one of @latebirds old posts, and the brown wire runs from the stator to the ground on the coil with a side stop grounding out on the engine block. I would replace that wire (with the appropriate color so you know if you ever need it again)

I’d be looking at fuel at this point. Provided you have ruled out compression, spark, and timing.... the last piece here is fuel. How long did the bike sit after he couldn’t get it to run? On top of that, what kind of crazy weird stuff did this guy do to attempt to seal up the carb? I flipped one a month ago where the guy basically said similar things to me, but he had “cleaned the carb” so I immediately looked at it and it was “fixed” with rtv and jb weld to keep it from leaking..... LoL. I changed the plug, starter, battery, and of course the carb. Viola it ran like a champ. People do some crazy homemade “fixes” and you really can’t trust them.

pic is from @latebird View attachment 150275
Top right has guidelines for testing your stator with an ohmmeter.
 

·
Registered
Joined
·
11,903 Posts
If the spark is good and in time - it has to be mechanical, compression, carburetion or exhaust
 
1 - 18 of 18 Posts
Top