Tri-Moto running issue

[Tri-Moto]

My 1985 Yamaha Tri-Moto 125 runs great without the airbox, however when you put the airbox on it runs like crap and has no powereven with the lid and filter off. Does anybody know what causes this? Its the same as a Blaster engine just smaller. I had 2 Honda ATC 110's that had the same issue. Thanks

 

[Herpderplol]

Jetting could be off.

Is the filter clean?
Intake on lid got crap in it?

 

[blasterdemon7]

It's not a f**king tractor !lol.

 

[Tri-Moto]

Haha I've heard that. Except it isnt a very good tractor, Yamaha advertised them as a work/utility machine but they have no low end power of torque. I did a compression test and it shows 105 psi (spec is 100 psi) the carb jets are factory size so im not sure what its problem. I was thinking of using a clamp on filter directly on the carb. Any thoughts about that?