crf 450

[hanna]

Does anyone have information about the carb maintenance? My 450 has been getting harder to start, seems a little sloppy as if maybe needing a full overhaul. I race a couple times a year and trail ride often.

[mxaddict]

In most cases the bike becoming harder to start is an indication the valves need adjustment, as one of the first symptoms of them getting too tight is more difficult hot starting. I would bet that is the culprit, and not the carburetor.

[Realfast]

I would agree. And if you are going to adjust them you might as well put new valves in because when I adjusted mine 2 rides later they were the same as they were before I adjusted them. The valves were way shot.

[NOR_CAL_WR]

OK, so mine has become increasingly hard to cold start. After it has warmed it hot starts no problem. Could this also be valves?

[Realfast]

Yes because when the motor gets hot the valves will expand causing them to get tighter.

[NOR_CAL_WR]

So I have heard about Blackdiamond valves being a better choice than stock, is this true? Also, what can I expect to pay to have them replaced? In other words, how many hours will Honda charge me for this job? Should I replace the rings while in there if the piston is still in good shape?Thanks

[Realfast]

I dont know anything about black diamond. Honda will charge you a lot of hours, I would suggest doing it yourself if you can. If your just adjusting valves i wouldnt wory aout rings. It your replacing valves i would put in rings.(its only one more bolt to get the jug off.)

[Ty]

NOR CAL, turn your fuel screw out, it could be that it is harder to cold start because the bike was lean to begin with, and the weather change (cooler) your having is causing it to go leaner. When the valves get to tight, it gets harder to start when hot. Make a habit of checking your valves anyway.