Snowmobile Fanatics banner

1 - 6 of 6 Posts

·
Registered
Joined
·
841 Posts
Discussion Starter · #1 ·
I have a 1995/6 polaris scrambler 400 2 stroke. i just bought it a couple weeks ago blown up. I need to find out how to measure a cylinder precise enough to tell me if it has been bored or not. The stock bore size should be 83mm. the piston is in like pieces so finding any numbers on it is out of the question. Is there like a special tool or something that measures the cylinders bore? any help would be greatly appreciated. Thanks guys
 

·
Registered
Joined
·
2,731 Posts
^one of those, or digital/analog vernier caliper
 

·
Registered
Joined
·
1,716 Posts
As a machinist I can tell you there are only two acceptable accurate method's for measuring a cylinder bore.
The reason I say only two, is that after 30 yr's of machining, I find Inside Mic's to be too big a pain in the ass to use, to be worth the effort expended.

The best and most accurate is to use a Dial Bore Gage, and take measurenent's at several different point's around the circumfirance (Sp), and at several different depth's in the bore.

The second method is to use a Telescoping Bore Gage, and a Micrometer, in the same style of pattern as you would use the Dial Gage.

A Vernier Caliper is not truly accurate enough, or versatile enough for measuring cylinder bore's.

If you don't know what these tool's are, or have never used them before, it would be best to have someone who is familiar with these procedure's take the measurement's for you.

Rick
 

·
Registered
Joined
·
9,987 Posts
Agreed... Take the jugs (or complete engine) to a shop, and watch them as they measure it. It should take them all of about 2 minutes, and you learn the process so you can DIY the next time.
 

·
Registered
Joined
·
841 Posts
Discussion Starter · #6 ·
well i work in a small engine shop now. but they dont do atvs or anything. just lawn equipment motors. but since i work there they are making an acception. I will ask if they have any of these tools. im sure my boss has the tools since he puts pistons in tractors all the time. thanks for the info guys! just as an update. i did order all the parts to my wheeler that i needed. Im just waiting for the crank and waterpump bearings to arrive. I should have her going in a couple of weeks.
 
1 - 6 of 6 Posts
Top