400ex with Yosh pipe dyno'd

Ok all you Yosh Pipe fans here are the gains of installing a Yosh to a 400ex. This 400 is my nephews who wanted me to do some work on it for him, along with myself learning and doing some posts of what good some of the bolt on hop ups will gain. It has a ported head with a stage 2 hot cam for other hop ups and was a stock pipe till now. Here are the results of the hp and tourqe. The gains are not what i expected. Click on the link for a better pic of the dyno sheet. The pipe actually caused a loss of TQ. The blue was stock pipe and red line is the yosh. http://www.hondaatvforums.net/forums/attachment.php?attachmentid=396&stc=1&d=1266547961