I have an 05 trx400ex. Traded for it a few months ago. Motor is all stock. Has stock air filter with cover removed and a white-bros e-series muffler. Im from NH so I searched and decided to help with the common starting issue I would rejet. I replaced the pilot with a 42 and the main with the 160. This thing still will not start without some serious fighting. All fluids were just changed and no signs of tainted oil. Does not smoke at all. However, it does have a tic. Sounds like a ac compressor on a car. Every 5 sec or so it tics, at idle or in travel. Nuetral or any/every gear. Not steady so I dont believe its the valves. Almost like it cuts out for a brief sec each time. Dont believe its fuel related. Questions...what else can I do to help this thing start? It's kept in a heated basement and still wont start. The choke is a joke. Once its running, it will run good with the exception of the random tic which will cut power regardless of where I am in the band. Bad cdi? voltage regulator? Has brand new battery. The battery ground is good. I rather not pay a dealer to fix, but Im not familar with Honda's and dont want to just start buying stuff. I also never removed the choke with the pilot change (should I?) Is the 160 main to lean/rich? Quad runs great except the tic. If you have read this far, please chime in.

 

removing the choke only gives better throttle response.i would leave it on.my 07 has hmf slip on 155 main 42 pilot just to compare.my owners manual says at least 91 octane.mine does tick once in a great while but at cold start up when it idles too low.not sure about the ticking.check air mixture screw i believe it should be two and half to three and half turns out.jetting sounds close.hope this helps a little.also does it have an adjustable needle in the carb slide mine is in the middle slot

 

Not sure which position the clip is in. However, the bike runs great throughout band with the exception of starting and the click. Would think a fuel or carb issue would effect the band somehow?