I have a 91 Blaster that I can't seem to get running correctly. It starts 1st kick and idles perfectly but won't rev at all when the throttle is pressed in. It is a stock bore without the airbox lid, pilot jetting is stock 32.5 and main is 290. I have tried main jets from 290-230 with no change. All the TORS system and original parking brake systems have been removed.

 

Have you tried it with the airbox lid back on? It could be too lean on the pilot. If it will rev with the throttle at wide open position then that would be an indication this could be your problem. Also make sure the pilot jet is clean. Other things to check are reeds, compression, timing, and needle clip position.

 

It will idle fine but boggs/cuts out at any throttle position above idle. Jets are all clean, compression is 125psi, reeds are in good shape, I replaced the woodruff key as the one in there was too small allowing a slight amount of play.

 

I would try to block off the airbox top with duct tape or the airbox lid if you still have it. You could be way lean. If it runs with the airbox lid on then you need to up your jetting sizes. Did it ever run with this setup?

 

I inherited this quad as a project and it has never revved in this configuration. That's a good idea about covering the Airbox, I will try that and report back. The wiring is a bit of a mess from the previous owner when they removed the TORS system, I traced the wires to verify the 5 wires to the CDI were correct.

 

Also make sure you have a good strong spark.