I have stock a 450r, i want to run it with out the spark arrestor and without the airbox lid. What would be the correct jetting for this setup. alt.900ft.

 

I'd try 165, 168 and 175 jets. Get all three and play with 'em.

 

thanx fo the info.

 

I bought one of those 2 inch exhaust tips on ebay, cut open the airbox lid, bumped up to a 180 main, switched to a size 50 pilot jet (from a 48) and lowered the clip on the needle to the bottom position, position 5.
By doing all this I didn't need to change the mixture screw adjustment.
It makes a big improvement. I would suggest getting the 2 inch tip as opposed to just removing the spark arrestor.

I also just added a stage II Hotcam. Haven't had any seat time since the hotcam but I'm going out this Saturday

 

buy a good jet kit as you will end up tweaking the carb later too. I have heard mixed reviews on dynojet kits, some out of dumb luck get good results and others are left feeling frustrated and mad and just sell them on ebay. I would suggest going on ebay and looking for a kit that sells jets. That is all you really need.