1999 Polaris 400l sport
#1
#2
Sounds like the engine may have been re-bored to a larger piston size in the past. Some companies identify oversize pistons by a letter. "A" is normal, "B" is maybe a few thousands oversize, then "C". a few thousandths larger and then "D", usually the largest oversize. I never saw an "F".
However, due to problems in the castings, or machining issues, sometimes the factory bores out the cylinder to an oversize piston in a new engine and you find it in your brand new ATV, Motorcycle, truck, car or boat. I rebuilt a Ford 302 back in the 80's that had 3 oversize pistons and it was bought brand new by my mother 9 years before.
However, due to problems in the castings, or machining issues, sometimes the factory bores out the cylinder to an oversize piston in a new engine and you find it in your brand new ATV, Motorcycle, truck, car or boat. I rebuilt a Ford 302 back in the 80's that had 3 oversize pistons and it was bought brand new by my mother 9 years before.
#3
It seems that Polaris has three piston sizes for that engine and year. Standard, .25mm and .50mm oversize. Interestingly, it seems the oversize pistons are quite a bit cheaper. Naturally, they also sell oversize rings.
looking around the net, I see markings of 5W25 for .25mm oversize and 38B50 for .50mm oversize on the top of pistons. The standards just have a triangle and a 3 digit number.
looking around the net, I see markings of 5W25 for .25mm oversize and 38B50 for .50mm oversize on the top of pistons. The standards just have a triangle and a 3 digit number.
#4
It seems that Polaris has three piston sizes for that engine and year. Standard, .25mm and .50mm oversize. Interestingly, it seems the oversize pistons are quite a bit cheaper. Naturally, they also sell oversize rings.
looking around the net, I see markings of 5W25 for .25mm oversize and 38B50 for .50mm oversize on the top of pistons. The standards just have a triangle and a 3 digit number.
looking around the net, I see markings of 5W25 for .25mm oversize and 38B50 for .50mm oversize on the top of pistons. The standards just have a triangle and a 3 digit number.
Mine has a triangle then 38B opposite of triangle
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