1982 XR250R piston slap

J

juniordragster123

Member

Feb 13, 2009

29

0

• Mar 9, 2009

• #1

Hey guys its me again. I am rebuilding this motor and I noticed when I put the piston in the bore without the rings on it has quite a bit of piston slap but at the bottom of the bore where the stroke doesnt reach it feels brand new (Normall). But the piston skirt looks brand new and the bore still has execellent cross hatching (Not worn out). Is this just normall factory specs?

 

Rich Rohrich

Moderator / BioHazard

LIFETIME SPONSOR

Jul 27, 1999

22,839

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Chicago

• Mar 9, 2009

• #2

Did you measure the bore, and check the taper?

 

J

juniordragster123

Member

Feb 13, 2009

29

0

• Mar 9, 2009

• Thread starter
• #3

I've measured the bore but forget the number, How do I check for taper? Thanks for your help. EDIT, When I measure the bore can I just measure the very top or how deep do I have to go into the bore?

Tyler.

 

Rich Rohrich

Moderator / BioHazard

LIFETIME SPONSOR

Jul 27, 1999

22,839

16,904

Chicago

• Mar 9, 2009

• #4

You'll need to get your hands on a bore gauge and a micrometer big enough to measure the piston. Every drag racer I've ever know has those tools, so you should have no problem finding someone who has them and who can show you how to measure the bore.

 

J

juniordragster123

Member

Feb 13, 2009

29

0

• Mar 9, 2009

• Thread starter
• #5

Yeah I can get those tools. Get back to you ASAP.

 

J

juniordragster123

Member

Feb 13, 2009

29

0

• Mar 12, 2009

• Thread starter
• #6

Ok I got it checked out at the shop at school and they said it has way too much slop. Now that I look at it the previous owner honed it out ALOT and thats why the bore is too large for a STD piston. I'm going to get it bored .25 or .50 over and buy a new piston and ring set. Thanks guys.

Tyler.