Graves Motorsports

AB007

98-03 YAMAHA YZF-R1: Graves Smog Block Off Plugs

Spark Plugs

Graves Motorsports Smog Block Off Plugs are designed to seal off the ports on the cylinder head used by the air injection system (a.k.a smog pumps or AIS).
Once these are capped off, the air injection system can be safely removed.
Made from machined aluminum.
Sold set of four.
There are two reasons why you want to remove the air injection system from your bike: If you are using your motorcycle on a closed course (racing, track days, etc.) you will want to remove all unnecessary equipment from your bike for reduced weight and ease of maintenance.

To get an accurate Air:Fuel (A/F) ratio when dynoing the bike, the air injection system pumps fresh air directly into the exhaust stream in order to burn off any unused fuel. Unfortunately by doing this the A/F ratio is thrown off by the extra "fresh air" in the exhaust stream. By removing the air injection system you can achieve an accurate A/F ratio.

Sealed Power 12162P1.50MM Piston
Dorman 939 116 Steel 16x6 5 5x112mm 939-116
Mix me 3648