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'86 Polaris Indy Trail 488

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'86 Polaris Indy Trail 488

Postby '86_indy_trail » December 14th, 2005, 2:49 pm

Hi,
I picked up a '86 indy trial 488 for $500 the other night, with 1,001 mi on the odometer, and in nearly mint condition, if it werent for a couple small cracks in the hood. The it started first pull before I bought it, started first pull last night, started first pull this morning, then the cord broke. I put another on tonight. I take it out of the shed and try to start it. I pull, and pull, and pull, and it is not starting. Not normal for this sled, in my opinion. I smelled gas, and pulled the plugs, and it was badly flooded. I have pulled the plugs at least 5 times now, and it keeps fouling them. I can get it to fire once or twice, and then I have to pull them and dry them out. I did top off the tank last night, but I don't think it is the cause of this flooding. It has very good spark, great compression, it is just not normal for it to flood like this. I know a bit about carbs, especially on my four wheeler, many small engines, and a friend's '77 Honda XL175, and I don't want to sound like an idiot, but can someone point out the air screw and pilot jet to me? I think I know what the air screw is, I have adjusted it many times, but don't exactly know what it is, and I think I know where the pilot jet it. The sled says 1 turn I think for the air screw, but I counted turns on it on one carb and it was 4 1/2. I messed up the other carb. I am thinking maybe it was jetted, since it does have a lightly studded track (48 studs). After a few hours of working on the thing tonight, I gave up and took the '79 Jag 3000 f/c out for a ride. ;)

If someone could help me, that would be great.

Also, note the Jag in the background in one of the pics. :)

[img]http://tinypic.com/ilyix1.jpg[/img]

[img]http://tinypic.com/ilyh6s.jpg[/img]
'86_indy_trail
 
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Joined: December 14th, 2005, 2:35 pm
Location: U.S.

'86 Polaris Indy Trail 488

Postby 02 PRO-X » December 15th, 2005, 1:57 pm

Sounds like after sitting the needles and seats let extra fuel in the crank case. Look for a small plug (bolt w/a gasket) at the bottom of the crank case, front of the engine. There should be one for each cylinder. Remove them and let any excess fuel drain out. Replace and dry your plugs, and giver er a wirl.

Really when you are done with the sled for the day you should shut the fuel off. This will help prevent what you experienced. Unltimately the needles and seats will need replacing, but they will work fine for now.

As for the air screw, should be towards the rear of the carb on the right side (as if sitting on the sled). They are in the carb at an angle. Start with 1-1 1/4 turn and go from there.

Hope this helps.....-Eric-
I'd rather laugh with the sinners, than cry with the saints.


[img]http://img205.exs.cx/img205/6434/prox7cjsm5vm.jpg [/img]
02 PRO-X
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'86 Polaris Indy Trail 488

Postby '86_indy_trail » December 15th, 2005, 3:00 pm

That's what I thought. I shut the fuel off last night so it didn't siphon itself out, if it even could for some odd reason (didn't want to find 7 gallons of gas on the floor). I pulled the fuel lines, and ran the carbs dry. I was planning on filling each carb with "sea foam" carb cleaner. Figured it might loosen some gum. But, it was running fine on the little bit of fuel left in the float bowl, then it started running faster like all engines (at least ones I own) do when the fuel/air mix is changed by fuel amount. I shut it off and stuck the lines back on, and drove it right out the shed. I set up the air screws to 4 turns, and it now idles nicely. I put 5 miles on it tonight; I ran around the lake twice and hit some slushy spots. I think the ice is at least a foot thick there; we just got aobut 8" of snow, and I think it was pushing water up. The studs gave nice traction there. For some reason, at about 7000 rpm, it only does about 40. Maybe because it was powdery snow, but it seems like the '79 Jag 340 can do 40 at a lower rpm (no tach on the Jag, no speedometer either. Mabye it just feels faster on the Jag, since that is such a light sled. I don't know. When the snow is packed a little, and I know where all the slushy spots are, I'll see what it can do. It seems like for a 488, it could do more than 40 at about 7000. Maybe my belt? It is a new Polaris belt, that the previous owner bought, but the right one? The jag seems a bit "zippy'er" than this thing, tonight.
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