weird problem with my 450f


4 replies to this topic
  • ChasNMe

Posted January 09, 2009 - 05:59 AM

#1

Last time I went to the track my bike wouldnt run very well. I could start it up and idle but most of the time it would cut off when I tried to give it gas or put it in gear. I had recently had my valves adjusted because they were way off. If I remember correctly they were .16 .16 .21 int, .29 .50 exh. Anyway this was the first time riding after that, although the mechanic said he rode it around for awhile after the valve job.

I am not a mechanic by any means, I can change my fluids and do minor stuff but engine/carb issues are over my head. I had a friend show up and he knows a bit more than I do. First, he found the needle valve all the way in so we turned it out 2 turns and thought that would be it. Nope, same issue. Then we took the bottom off the carb thinking maybe it wasnt getting enough gas or something. Nope, the main jet was sitting there in the bottom. Wow, that must be it. We fixed that and thought I would be good to go. Nope, same issue.

I started to notice though that while leaning to the left, whether on the side stand or me starting it, it would run, but as soon as I pushed the bike over to the right side it would kick off. Immediately it would shut down, and I am talking about just past straight up. I told my friend what I thought and we tried it about 10 or 15 times. Started it and left it to the left 5 seconds sometimes, 20 seconds sometimes, 30 or more seconds a couple times, shift it over and dead, shut right off.

So we are thinking electrical issue. At first we thought it was a carb issue but if it was, I wouldnt think it would be immediately shutting off. What do you guys think? I appreciate the help. Jake

  • grayracer513

Posted January 09, 2009 - 07:08 AM

#2

Judging by the fact that the valves were loose (they normally tighten as they wear), and the fact that the main jet was laying in the bowl, my guess is that someone who, to be charitable, is unfamiliar with the bike has had it apart. I suspect that the float in the carb is improperly assembled/adjusted, by with so much wrong with it, it's anyone's guess.

Check back with your shop to see if the numbers you gave here are the actual original clearances. You might want to take the bike to a second shop, have the valve clearance checked, and get the problem diagnosed. Don't tell them about the first shop, and ask them to diagnose the problem before doing any repairs.

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  • ChasNMe

Posted January 14, 2009 - 06:36 PM

#3

that someone (charitably speaking as unfamiliar) was me. i had originally thought that the bike not running correctly was a carb issue and a friend said to get a new float and needle valve. he said it was pretty easy to change. i thought it was, but i must not have tightened everything up enough.

not sure why the valves would be loose. the numbers are correct, they were loose. honestly, i dont understand what causes valves to get loose or tight. i thought more wear was loose but apparently not.

in my first post, it was the pilot screw that was turned all the way in. i mistakenly called it the needle valve.

the guy who has my bike now says that my issue is the stator coil. could that cause the issue of it not running, assuming my carb and valves are ok now? it is wierd that just shifting the bike over to the right side even 3-4 inches shuts it down. thanks, jake

  • grayracer513

Posted January 14, 2009 - 07:45 PM

#4

not sure why the valves would be loose. the numbers are correct, they were loose. honestly, i dont understand what causes valves to get loose or tight. i thought more wear was loose but apparently not.

the guy who has my bike now says that my issue is the stator coil. could that cause the issue of it not running, assuming my carb and valves are ok now? it is wierd that just shifting the bike over to the right side even 3-4 inches shuts it down. thanks, jake

It depends on where the wear occurs. If the lifter or the tip of the valve stem should wear, then the gap would grow larger. But this virtually never happens. Generally, what wear takes place does so at the valve face and seat. This lets the valve move up into the head, reducing the clearance.

The stator could be at fault. They can fail in such a way as to be sensitive heat, vibration, or a number of things, but lean angle is a little strange. Is the engine unusually noisy at idle?

  • ChasNMe

Posted January 18, 2009 - 07:01 AM

#5

not that i would say, but are you talking about just how overall loud the engine is or do you mean something specific like a rattling sound or something. i suppose either way i dont think its noisy. my other bike is a 97 kx250 and it has a little exhaust rattle that makes it quite loud.





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