I'm working on my 1995 scrambler to get it all ready for spring and I am pulling the plastic off so I can give everything a good cleaning and make some of the stuff I'm going to work on, easier to get at. I pulled the plug and did a compression test and got around 127 psi on the gauge. Guy that had it before me hastily put it together so I have to tighten up the motor mounts and the top one is completely loose because the nut was never put on the one side. I was poking around looking things over and I noticed this weird plastic doo hickey attached to the carb to engine boot. What the heck is that for? I have worked on a bunch of these 400's and never seen this before. It looks factory so polaris put it there apparently. Is this a type of silencer like what is found on many of the air cleaner setups on cars today?

Thanks,
Mike

 

Called a boost bottle.It helps catch unused back wash fuel/oil mixture from the engine before it gets fully into the carb and sprays out the back of the carb when the slide snaps down. Stores this mixture to be used in the next fuel charge into the engine.Some people liked them,others just removed them and blocked them off. Supposed to help cut down on bogging also,better fuel economy but again a lot of people didn't like them. Actually a hold over technology from the 70's and early 80's.

 

Thanks OPT,

Sounds like it's a scrambler and sport thing so since polaris put it there I will leave it well enough alone.

I'm checking the engine over and I did a compression test and that was good so I went ahead and did a cooling check. Pumped up the system to 10 pounds and let it sit over night. No drop at all so I should be good, right? Not sure if I need it to hold more pressure or if 10 pounds is fine.

Thanks,
Mike

 

10 psi is good,especially with no drop in pressure over night.

 

I got the old girl up and running today. Runs strong and starts right up. Just have to get some new exhaust donuts for the head pipe. They fit ok but it does have a lot of noise coming out of that area and you can feel the exhaust blowing out around the joints. I tightened up all the motor mounts the guy had left loose and replaced a lot of nut and bolts that never were put in because the guy just threw it together. Hard to imagine this guy was a mechanical engineer that worked for a bridge company. The only thing I question now is this runner isolater at the back of the motor. Is there supposed to be a gap between it and the transmission? I see it is adjustable but haven't found anything about it in the manual.

Thanks,
Mike

 

Isolator should be touching the frame.Loosen the outer nut if you have to until you can grab the inner nut and loosen it. Turn the rubber isolator until it's snug with the frame.Tighten the inner lock nut against the inside of the bracket,then tighten the outer nut. If you need a new one there sill out there.POLARIS OEM NOS ATV MT,TORQUE STOP,RUBBER FITS 1999-2002 XPLORER 400 3110048 | eBay Note: some just have the outer nut and not an inner lock nut,but your model appears to have it on the parts break down. Item#34.http://www.cyclepartswarehouse.com/o...ting-scrambler