I got a 1997 Polaris Explorer 400l that i rebuilt the motor in last year from the bottom end up. I bored it .020. I had it over heat on me the other day n while i was checking things out i discovered antifreeze in the exhast pipe. Could it be a head gasket or something else? Any help with this would be appreciated. Thanks.

 

Possible head gasket blown if got hot,plus if you tear it down,I would check for any head/cylinder warping(any machine shop can check this out) Plus you already probably know to bleed head after coolant is in to remove any air bubbles or could do the same thing again and over heat,had a couple guys that did their own rebuilds after I bored the cylinders and forgot! Over heated and blew the gasket. Also was fan operating ok? OPT

 

K. Thanks. I will try that n check it out. Does the cylinder need to be removed n checked or just the head?

 

When you take the head off, just hold cylinder and push piston down,if any damage the cylinder will usually show it! Scored cylinder wall,etc. If any doubt about piston just remove cylinder,base gaskets cost is not that much for peace of mind! OPT

 

Got the motor put back together and running great! No leaks. Thanks everyone for your help. FYI i was talking to a mechanic the other day and he told me that on the polaris atv's it really important to retorque the head and cylinder base bolts. Its supposed to help stop leaks from the head gaskets and also prevents the cylinder from working loose and breaking ears off. Thanks again for all the help!

 

Got another issue now tho. When i drive my atv i can speed up at wide open throttle but it soon dogs down like the ignition or something is stoping it but when i release the throttle n run only half it runs fine. then if i open the throttle up again it dogs down again. Is there a throttle position sensor as on a car or something that could be causing this or a rev limiter? Thanks for the input

 

ant got as deep in to my xplorer as you yet,...but with cheap 87 gas mine boggs bout half throttle,...an if i get a lil to much oil in gas it ant as crisp,...new plug helps this i will say,...i was scared id blow head gasket on mine so i removed sending unit from back of head an installed a heat gauge,same as old chevy,..worth ever penny an the 45 minute to install in pice of mind!! ride all day an itll stay between 180 an 185,...every once in a while if both kids are on it with me in lotta hills itll almost reach 190,..then fan comes on,an i wired up the heat light to shine when fan runs....like knowing it ok!!!good luck,..love my xplorer!!!

 

how does the plug look, meaning is it running a little lean/rich? wondering if maybe it's not got enough fuel at WOT to feed it? just a tought.

 

put a bigger fuel filter on and it seams to be working now. Thanks for the help