I just installed A full mbrp system stage 1 hot cam and twin kn's with no air box .I changed the mains to 165 170 back the pilot three turns and needle clip is on the third notch.When i try to start it will fire off but will not run my elevation is 800- 1000ft double checked valves and timing and there perfect so i beleive its jetting problem with all of my new mods.Can any one give me some good places to start

 

I pulled the rocker cover back off and double checked the timeing and its on and so is the gas and the carbs are tight.It is acting like its not getting enuff full,it will fire off for a sec then turn over and over pop again etc tried giveing throttle,choking,half choke,no choke,full throttle,every senerio to figure out whats up with it and just cant get it whipped

 

sounds to me like timing is 180 degrees out
if its popin back but hey i may b wrong just my 2 cents

 

This may sound stupid, but did you put your spark plug wire back on? Or did you try to turn it with a wrench to make sure the valves werent hitting the piston? Other than that You may want to check the valve timing like YamahaRaptor660R said. Did you match up the yellow mark on the chain to the top of the cam?

 

I didnt think u would be able to install it 180 degrees off.... check the plug and see what color it is, if it is white then u are lean if it is black then your rich, it will get you a ballpark figure of how the jetting is, with K&N with no airbox alot of air will flow in there. I have a Pro flow foam with stage 2 web cam 11:1 piston big gun exhaust dyno jets are at 185:180 at 1000 elevation

 

tell me about this yellow mark on the timing chain the manual and hot cams instructions didnt say any thing about that.I put the engine on top dead center with the timing mark in the inspection hole and made sure it was on the compression stroke and installed the cam on the timeing gear as per the instuctions and the cam in the right postion with the two holes up,and the marks on the timing gear level with the head.Im almost postive the cam and timing is on the money,Im leaning more towards jetting prob but will double check every thing out again tomorow,what is your guys opinun on the pilit screw three turns out 4 turns out,i beleive im running lean thats why its not firing,any ideas for me to check are greatly appreciated im going to jump on it again bright and early

 

Increase the main jets leave the air screw at 2 1/2 half turns keep the pilots in the stock possition. check the plug man, thats the best way to see if jetting is off.

 

Check the floats. Sounds alot like what happened to me

 

I am going to guess its going to be his floats. before you tear into your head again try to cranck it. If it does, great, and then dies try draining your carbs. Turn the fuel off at the tank. Then open the drain screws on each carb till no more comes out. The drain screws, if you don't know are the ones at the bottom by the hoses. After no more gas comes out gently snug the screws back, DO NOT over thighten them. Turn your gas back on and try and start it again. This SHOULDtell you if its your floats.

Thats just my opinon and I think it might be easier then taking off your head cover.

I agree with airraptor that your jetting is close enough to run.


When it runs, how long before it dies?

 

Yup, like the old "beat on the starter and it will crank" trick. If your floats are stuck this could work.