A few days ago I bought a 2001 polaris scrambler 400 2x4 that had set for 5 years off of a lady for $375. She said she parked it after it wouldnt start one day. I brought it home changed out all the gas lines,tried changing the oil but im kinda stumped on that.( Im new to 2 strokes and polaris) what is the oil tank up on top of the radiator for? And what oil is in where the yellow dip stick goes? Where is the oil injector pump and where is its tank? After I put new gas lines in it I gave the carb a shot of starting fluid just to see if it would crank and it started and stayed running for a few seconds. then i filled up the radiator just to see if i could put gas in it and get it to run.(I pre mixed the gas a little just in case the injector pump was out) when I tried to pull start it it started blowing dirty looking water out of a link in the exhaust so I stopped and pulled out the drain plugs I could find because I am afraid it has ablown head gasket and didnt want water to be setting in the engine. Then i took the exhaust off and it was full of water too. Im pretty sure I fouled my spark plug doing that. Now I dont know what to do or where to start next. I need help! thanks!

 

Tank in the front is for 2 stroke injector oil. Yellow dip stick under the carb is for counter balancer oil(75ccs) Best to have a manual before you start spending money on a machine that's been sitting for 5 years. You can use this pdf service manual on the 400 engine as all are the same whether in a Scrambler or the earlier Sportsman 400s.Index of /ORV Manuals/Polaris/1996-1998 - All Models OR if you want a hard cover manual check out ebay.A lot of things to service and check out on this engine. http://www.ebay.com/itm/Polaris-ATV-2001-Scrambler-400-2X4-2-Stroke-Shop-Repair-Service-Manual-9917126-/131207592684?pt=Motors_Manuals_Literature&hash=item1e8c94faec&vxp=mtr

 

Thank you! Ive heard of people disconnecting the oil injection pump, is that a good idea? And i guess the oil and water i drained out of the plug on the engine was the water and oil mixed together from the pump and blown head gasket? Sorry for so many dumb questions just trying to get this thing running. thank you tho

 

On this model a lot of people did as the pump was in the front of the machine. You can pull the oil pump plate and see if the pump lever/spring is corroded or frozen. Before you worry about this I'd do a compression check OR since you had water in the cylinder I'd do a radiator pressure test. If the gasket is blown,when you pull the head you can see what shape the piston and cylinder is in.

 

Thanks I'll do that! And if the head gasket is blown Im guessing it will blow water out of the jug? And also do you know how much psi to pump the radiator up to?

 

10 psi since it has a 13 pound radiator cap rating.
How To Test a Cooling System using the Mityvac MV4529 - YouTube

 

Thanks! I'll try this tonight if I can get a hold of a tester.