Hi all I have a 98 xpress 300 and over the last 2 months it has been acting up. I have went riding a total of 6 times in these months. The first 2 lasted about 45 min when we shut off are wheelers to let them cool mine would not start back it cranks all day but will not start. So I would take it home start checking things out find nothing and the next day it would start right up. I tried changing plugs on the trail and still nothing. The thrid time I went out I road for about 2 hours shutting it off twice to cool and had no problems starting it back up. The next time was a repeat of the first. So I went home and checked the compression which was fine and also checked the carb adjustments which were fine also. So I need help with what might be causeing this. My first thought was the carb but then why would it run really good and then nothing . Then wait and all of a sudden it runs good again. Could it maybe be the coil ? any help would be great my wheeler is starting to get a reputation. The joke my freinds made up was ---- polaris ---- Fix Or Repair Daily ---- like the old ford joke so please help.

 

I was making the mistake originally of slightly depressing the thumb control as I cranked it over, like I would normally do with most cars

once I stopped that it starts without problems, so seems it can get easily flooded espec when doing hot starts

also even in tropics I use the choke for first start of the day and immediately snap it off once it starts [no idea if it would start in cold climates]

 

did you see if there was fire when you took out the plugs to change them? if they were firing then its not the coil. sounds almost like the bike was vapor locking when you shut it off. if it was flooding you could tell by the plugs being wet when you took them out replaced them.

 

well I did not check for fire yet because I thought that the plug had fouled. And the first time the plug was wet but I think that is because I tried several different ways to start it with choke and or throttle. So I probaly fllooded it then. But the next few times there was no fuel on the plug. I tried to get it to mess up today so I could check the fire but it ran really good for an hour and a half and nothing happened. Could this problem be from compression being to low its at like 95 to 100 hot and 110 cold. I would not think so but maybe. And could someone explain what vapor lock is. I have heard it used several times but never really new for sure. thanks.

 

no that 90 psi compression is fine and would have to be pretty low for it not to start. vapor lock is when the fuel will not flow from air bubbles in the line or from the gas or carb being extemly hot and vaporising the gas. if it does it again and have a hard time to start try taking the gas cap off and see if its under pressure. make sure the vent tubes are clear as well. just some idears, maybe not help but who knows.

 

well it happened again today so I checked the spark and it does have what I think is good spark. It is a nice blue color and is sparking on severl different places on the plug at the same time. As for vapor lock I now when I am riding and I stop and see how much gas I have left it does have pressure in the tank when I remove the cap. So is it supposed to have pressure or not. I have noticed that every once and a while my vent tube will drip a little gas. I thought it was from being full and going up steep inclines?

 

did you take the cap off and did it start right up? make that the lines arent pinched.

 

No even after releiveing the pressure it still does not start up. I checked the vent line and did not see any kinks right now. Do you think it is time for the carb to be overhauled maybe. I am just looking for a solution anywhere. I really want a relaible machine again.

 

anyone have any ideas. I am stumped

 

Try wrapping the fuel lines with heat tape, you can get a roll at home depo, Ive had both of my machines vapor lock when hot but they have started after 10 or 15 minutesof cooling. Since I wrapped the lines I havent had any problems.