polaris sportsman 335 bad throttle bog
#31
01-31-2018, 08:11 AM
#32
10-13-2018, 01:06 PM
Did you win on you polaris 335?
Checked all vac lines for leaks
checked tank vent
new fuel pump and all lines, pumps great
new carb
adjusted air screw and float
good compression
good leakdown, 5% or less
new battery
new coil
new plug
new cdi and voltage reg
all new fluids for fun
Valve lift is good
only revs plugging intake, or no muffler. Both increase vacuum.
I have plenty of manuals, and know basic troubleshooting.
Im stuck at timing chain/sprocket wear, split woodruff key, or cylinder wear on bottom half of cylinder. Any one else have thoughts before I do surgery?
checked tank vent
new fuel pump and all lines, pumps great
new carb
adjusted air screw and float
good compression
good leakdown, 5% or less
new battery
new coil
new plug
new cdi and voltage reg
all new fluids for fun
Valve lift is good
only revs plugging intake, or no muffler. Both increase vacuum.
I have plenty of manuals, and know basic troubleshooting.
Im stuck at timing chain/sprocket wear, split woodruff key, or cylinder wear on bottom half of cylinder. Any one else have thoughts before I do surgery?
#33
10-13-2018, 03:04 PM
I actually just got it running.
valves were very tight, after adjustment, ran very well... for 5 minutes
pulled carb for 15th time, was already full of varnish. Intake boot caked with honey-like varnish
replaced all fuel lines, added filter, added b12 chemtool to gas, no change.
ran some seafoam spray through carb, immediately started running very well. Best guest is varnish caused intake valve to stick but only when running.
also closed the idle air screw 1/2 turn, now idles properly without choke.
it took me a YEAR to figure this out, I was ready to rebuild motor, hope this helps. My first time using seafoam, more of a bandaid, will pull head and rebuild if it happens again. Hope this helps, let me know if it does!
valves were very tight, after adjustment, ran very well... for 5 minutes
pulled carb for 15th time, was already full of varnish. Intake boot caked with honey-like varnish
replaced all fuel lines, added filter, added b12 chemtool to gas, no change.
ran some seafoam spray through carb, immediately started running very well. Best guest is varnish caused intake valve to stick but only when running.
also closed the idle air screw 1/2 turn, now idles properly without choke.
it took me a YEAR to figure this out, I was ready to rebuild motor, hope this helps. My first time using seafoam, more of a bandaid, will pull head and rebuild if it happens again. Hope this helps, let me know if it does!
#34
10-02-2020, 11:50 PM
I see you have given a lot of polaris help.. I have a 2000 polaris sportsman 335. just did top end( bored .10 over and valve job), new fuel pump, new cdi, new after market carb and air cleaner. engine starts, idles perfectly but when I even attempt to throttle up I get a bogging. Its in the throttle low range. when it gets hot it still bogs but its less and at times i can get it to throttle up into secondary. I checked for air leaks and used carb cleaner and got no change in engine speed when spraying carb area , vacuum pulse line to fuel pump, and air box connections. Only when I put my hand partially over airbox intake it will throttle right up. When I did top end it went out to a guy named ANDY in texas who machined the cylinder and redid the valves. I get no blow bye. He did see slight wear on exhaust cam lobe but told me that after cleaning up it was satisfactory.I am disabled and purchased this for hunting and way overpaid and now have spent a lot already trying to solve this problem. my buddy thinks this is a vacuum problem. I think since we changed the size of piston and cylinder maybe a jetting problem with not enough fuel...any thoughts?
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