Polaris ATV Forum banner

1 - 8 of 8 Posts

·
Premium Member
Joined
·
996 Posts
Discussion Starter #1
Hello everybody, been at this for over a year now playing catchup on maintenance from previous owner. i have a 99 sportsman 500

the carb has a rebuild kit, so do both clutches
Currently:
The problem started intermittently, that was when I thought it was carb and cleaned it many times, then got a rebuild kit for it. That didn't work, and by then the problem was constant-lack of power. So compression was low, and I could move the crank side to side easily, so I rebuilt the whole engine, it just got back together and now I still have the same original problem, but with a better engine. Great, alot to show for all that time and money.
(The engine does make a loud ticking from the oil pump, it's a new one way valve, and when I squeeze the oil tank return hose and pressure builds, all ticking goes away.) That's one problem. The other is mid to full throttle range.

Right now the bike Will start and run. It sounds great at idle. It will pull pretty good to 20 mph and then all power drops off, dead throttle space when it hits 20, blip or hold at full no results.


I tested the resistances on the stator.
Green and black ( book 446) 453
Green and red (book 1.6) 4
White and red (book 97) 107
for the readings that should be infinity, no change in display of the meter (digital)

Went to check the stator output and got nothing, the multimeter flashes some numbers as i pull the recoil starter, but then displays nothing once it is running. the wires were hot. in the picture i posted the one coil is black, new ones are white and the other is a tan color, is this an issue?

After I started the bike, I pulled the black ground wire from the cdi box. And it continued to run. It would not turn off from the switch or the key like it always has, only the gauges would shut off, until I reconnected the black ground wire.Reading other stuff it seems this might be the issue?

i know theres a few questions, but i aprecialte any help.
Thanks a bunch!
 

·
Registered
Joined
·
668 Posts
Did you replace the cam? The pre HO 500s would burn the exhaust lobe down. There are a bunch of threads on that.
 

·
Premium Member
Joined
·
996 Posts
Discussion Starter #3
yes i did the cam and the rockers. they have about 20 hours on them now as i did this before the engine rebuild. when i had it apart the lobes measured up to specs.
 

·
Premium Member
Joined
·
996 Posts
Discussion Starter #5
the air and fuel filter only have a few hours on them
 

·
Registered
Joined
·
5,753 Posts
Did your rebuild kit come with the same size jets that were in it to start with? Did you still out the bad plug and get the mixture screw out, cleaned, and properly adjusted?
 

·
Premium Member
Joined
·
996 Posts
Discussion Starter #8
Just to complete the thread, It ended up being the carb diaphragm/block was worn and to loose so it was binding and not sliding open to allow air flow.
 
1 - 8 of 8 Posts
Top