YZ450F Starting problem
Posted 11 November 2002 - 02:22 PM
For starters I live in Tampa,FL but I drove to Tennessee to get the bike. So I am not sure if the stock settings on the pilot screw is different.
When I first got the bike I already did my share of asking how should I start this four-stroke (I have always had 2-strokes) and everyone told my not to use the throttle at all. Even keep my hand on the handlebars not the throttle when I kick it. Which I tried.
Here is the deal. If I stall it or drop it, I have a terrible time getting it started. Here is how I do get it to start though when I can. I Hold the throttle wide open. You guys are going to think I am crazy, but I swear that when I try the regular way of starting and when it does not work (Which it usually does not) I slowly turn the throttle to almost wide open and usually within a few kicks it will start (but it does burble at the beginning, then it comes around and starts). However there are times when it will not start at all. When the bike is cold or not real hot it will start. I think this is telling me that I am running to rich in the bottom. What do you think? I think I might need to mess with the pilot screw (which on a two stroke we call them air screws) which according to my manual it works backwards than normal. I race harescrambles and it is just killing me in my times and energy out on the track.
Please give me some advise. And what gas is everyone running? Would that make a difference? I am using 93 Octane from the pump.
Posted 11 November 2002 - 02:28 PM
Posted 11 November 2002 - 03:01 PM
And by the way, opening the throttle all the way while starting is essentially leaning out the start/pilot circuit. So you are right on the money with your technique!
Posted 11 November 2002 - 03:21 PM
What gas should I run?
Posted 11 November 2002 - 03:57 PM
The fuel screw and the pilot screw are the same thing. OUT is richer and IN is leaner.
I do that all the time! I edited my post above to reflect the correct behavior.
BTW - I run premium pump gas and have never had a problem here in Houston. I buy from a high volume station so I assume it's always fresh. But if I ever start having jetting or fuel problems I'll switch to a race fuel.
Posted 11 November 2002 - 04:07 PM
Posted 11 November 2002 - 04:22 PM
As for starting with the throttle wide open, my 426 will not even try to start like that. Best thing to do when it's flooded and the hot start button wont work is to turn the gas off and pull the compression release in and kick the bike over several times to help get the excess gas out. On my old XR, the only way to get it started after dumping it was to hold the throttle wide open but it didn't have the throttle position sensor or the accelerator pump.
Posted 11 November 2002 - 04:30 PM
As for starting with the throttle wide open, my 426 will not even try to start like that.
Man - I should just start over.
I didn't really mean to encourage that. Just that by letting in more air , he was on the right track.
Maybe I just need to log off for tonight - LOL!
Posted 11 November 2002 - 04:38 PM
Posted 12 November 2002 - 02:53 AM
It's got to be jetting. My 450 in Orlando starts every time on the first kick. No matter what the conditions it starts on the first kick. That is one thing I really do love about this bike.
Posted 12 November 2002 - 05:31 AM
Posted 12 November 2002 - 05:53 AM
Posted 12 November 2002 - 06:27 PM