OEM BOV Modification

Wednesday, April 11th, 2007
Adjustable BOVís to get from the stock boost level of about 10 psi to 11.3/11.4 range that Kawi advertised are now available. Price: $0.
The only catch? A bit of work is required.
First remove the plastic BOV (the one on the I/C). NOTE: Use a heat gun on the ribbed black outlet hose and it will practically fall off by itself. The alternate way is to pull very hard on it until it breaks as several other people have done Ė then you get to buy a new one.
Now the secret: the BOV looks like a single plastic piece but it is not. It is a 2-piece unit. Heat the round domed top with a heat gun until very hot. I then used a thin silicone kitchen hot pad to grip the top, rock it back and forth with some force and it slipped right off.


To adjust: while holding the 10mm bolt head on the seat end of the valve, remove the 10 mm nylock that was under the cap you removed. Remove the bolt and slide out the brass tube the bolt went through. Then remove the 21mm nut. The hollow shaft the 21mm nut was on is slotted. Turning the shaft clockwise increases the spring pre-load and thus the blow off pressure and vice versa.

The result should be virtually undetectable unless Kawi admits they never sold a ski that hits the advertised boost level. If someone familiar with Kawi sealers can ID the sealer used on the BOV top, it will be undetectable. The sealer (black in color) is not silicone and appeared to me to run out of the joint under high heat.
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The above info was provided by Dave from Texas. Why is this modification so inportantant? Well it seems as though several have tested boost level to find anything from 10 psi to as high as 12 psi max. This BOV is the unit that is responsible for regulating max boost levels. Doing this modification ensures that you are getting the full capabIe boost level out of the Supercharger. My boost level was showing a peak psi of 10.
At first we thought that the unit was put together using a glue that made it impossible to open the unit. Dave found out different. Once he showed us how, we started getting into it and found that it is indeed an adjustable style BOV.
Important part of this mod is using the heat gun to release the BOV cap. Carefull with the heat. You want it hot to the touch but not smoking.