09 WR450F - Dirty Piston Gunk?


6 replies to this topic
  • kylemaisel

Posted November 15, 2011 - 03:45 PM

#1

I have a 2009 WR450F with approx 600 trail miles on it. Original owner still like new. It tends to foul plugs every ride and i looked down the spark plug hole and the top of the piston has some gunk on it. The gunk seems to be somewhat like damp black soot but it has a brown color when smearing it (I'm guessing brown is from old fuel?). I took a picture of looking down the spark plug hole. Any suggestions on if this is normal? Anyway to clean it without taking bike apart? Any help would be appreciated.

photos: http://www.flickr.co...s/29534928@N05/

Thanks,
Kyle

  • Krannie McKranface

Posted November 15, 2011 - 06:46 PM

#2

I have a 2009 WR450F with approx 600 trail miles on it. Original owner still like new. It tends to foul plugs every ride and i looked down the spark plug hole and the top of the piston has some gunk on it. The gunk seems to be somewhat like damp black soot but it has a brown color when smearing it (I'm guessing brown is from old fuel?). I took a picture of looking down the spark plug hole. Any suggestions on if this is normal? Anyway to clean it without taking bike apart? Any help would be appreciated.

photos: http://www.flickr.co...s/29534928@N05/

Thanks,
Kyle


Can't see enough to tell. Pistons get carbon build up on them. If you use cheap gas, have stock jetting, don't clean your air filter correctly or often enough, have dirty oil, etc, you will get carbon build up. Also, if you don't "wring-out" the motor at least every time you ride (only when it's hot) you will get build up.

Now, if the motor was not broken in correctly, you could have serious ring blow-by, and you will get 'plug fouling' type issues.
Always use fresh gas. Always use fresh oil and a fresh clean oil filter.

  • kylemaisel

Posted November 16, 2011 - 10:28 AM

#3

I followed break in although the break in did not seem typical to me (1.5 hour manual said). I service the bike excessively. Always use fresh 93 octane. I'll try to get another picture. It's almost like wet sand looking but it's black and damp. I wring the motor quite often. Could it potentially be rich jetting? It was jetted by dealer when I bought it. How should I start on trying to diagnose it? Thanks!

Specs:
Ais removed
Fmf power core 4
Snorkels removed
Jet kit ( not sure which, dealer installed )
Grey wire mod
Throttle stop removed

All dealer modded before I bought it.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Krannie McKranface

Posted November 16, 2011 - 03:37 PM

#4

I followed break in although the break in did not seem typical to me (1.5 hour manual said). I service the bike excessively. Always use fresh 93 octane. I'll try to get another picture. It's almost like wet sand looking but it's black and damp. I wring the motor quite often. Could it potentially be rich jetting? It was jetted by dealer when I bought it. How should I start on trying to diagnose it? Thanks!

Specs:
Ais removed
Fmf power core 4
Snorkels removed
Jet kit ( not sure which, dealer installed )
Grey wire mod
Throttle stop removed

All dealer modded before I bought it.


That's your problem. Probably not jetted right.
You don't mention the fuel screw, or the leak jet, which need to be changed also.

  • GCannon

Posted November 16, 2011 - 09:12 PM

#5

I can't help but think you have something terribly wrong with your bike!

This is not a 2 stroke and you should not be fouling spark plugs. if you are you have a big problem:

Does your bike run like crap?

You must have one or more problems:
1 your ignition stater is malfunctioning and having trouble igniting the fuel. Get the manual and do all the ignition tests.
2 your jetting is really far off the mark reset to stock and start over.
3 you have a major compression or cylinder oil leak problem, Are you loosing oil?
4 someone did the wrong grey wire mod and disconnected the wrong wire from your CDI computer. first research then investigate.
5 your valve timing is off, you bike would run terrible

6 ignition timing is off because of poor stater alignment, or TPS adjustment off,

7 Poor compression????

Asking for a miracle on the internet is rather optimistic you need to investigate and provide more detailed information if you want to get more specific help.

Good luck and let us know how it goes!

  • kylemaisel

Posted November 17, 2011 - 06:09 AM

#6

Thanks for the replies. I'll continue to investigate further with the information you provided and keep you updated.

My bike seems to start and run fine. The only exception would be it gets a little boggy after about 15-30 mins of riding. (I'm guessing after plug fouls out). It's always starts first try everytime hot or cold. I'll double check oil level and cleanliness of oil (time for oil change now), but the oil level has always stayed the same.

In regards to:
Asking for a miracle on the internet is rather optimistic you need to investigate and provide more detailed information if you want to get more specific help.

I was just looking for advice on where to start. Thanks again for your reply, it's the kind of information I was looking for. now i know what kind of detailed information to provide. Maybe i should have stated that i'm new to most the engine performance type stuff.

  • beezer

Posted November 17, 2011 - 06:46 AM

#7

Your fuel screw is prolly out to far.




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.