The phantom air screw

[Stusmoke]

As the title suggests, my air screw on my 2001 honda CR125 decided to disappear. I only just noticed it was gone now, god knows how long its been missing for. I haven't been exactly gentle to it the poor little engine 

According to my local dealer whom I just paid $32 for a new one (What the F**K) There was meant to be a small spring on it. I always found the screw the be very loose and mine didn't have a spring on it. Thats why it fell out I'm guessing.

Anyways my worry is what the damage to the engine is. All the way out is leaning out the mixture after all  If someone could post up a video of a 125 pinging so I've got something to compare to that would be great. I'm also concerned that the heaps of dirt around the carb area would have gotten in through the place where the screw should be. I'll be pulling the cylinder today to have a closer look for debris. I checked the progress of the top end about 2 hours of riding time ago and it was in good order. Good results on the compression test. 145 PSI over 7 full kicks.

Cheers for your time and any advice you can provide.

I'll post up some pictures later of my top end.

[Stusmoke]

UPDATE:


This was an excellent start. I mean I already knew my jetting was rich, but when I saw this I was relieved that it wasn't white as snow.








Sorry for the awful shot.



If people could run their eyes over these crap photos and just tell me if I've missed anything, That would be great. Oh and by the way, I did rotate the circlip on the left side (when sitting on the bike) to a more secure position.

By my eyes, everything here is fine and dandy. But those with more experience will likely see something that I've missed.

If theres one thing we've all learned from this experience, its that Stuart will never be a photographer

Cheers guys.

[evo550]

You've got the top end off, put a piston kit in it. Simple.

[Stusmoke]

You've got the top end off, put a piston kit in it. Simple.

For real? Theres a rule that I live by... One of many. That rule is: If it ain't broke, don't fix it. Theres nothing wrong with this piston as far as I can see and its still showing good compression. Why would I replace it?

[arnego2]

Because the pistons live their life in a pretty harsh environment and can fall apart when pushing their lifespan.

[eprovenzano]

Since you've got her open, at least replace the ring(s)

[Stusmoke]

Since you've got her open, at least replace the ring(s)

Shes done ten hours now according to my calculations, when mxparts reopens I was going to buy a new ring for it.

Because the pistons live their life in a pretty harsh environment and can fall apart when pushing their lifespan.

Its done 10 hours.

[vetman]

gotta agree with everyone here as well ,ring minimum or piston,check the inside of your barrel for any scouring .In future if your ever worried about dirt getting through a great way is take your carb of and look in the barrel end if you see anything in there youve got troublealso have a look at your power valve they can get clogged up youll see if it moves freely or not.If your going to go new piston look into a forged piston ie.wossner,weisco or something sililar theyll last so much longer than standard cast pistons so long as you warm them up properly of course

[Stusmoke]

gotta agree with everyone here as well ,ring minimum or piston,check the inside of your barrel for any scouring .In future if your ever worried about dirt getting through a great way is take your carb of and look in the barrel end if you see anything in there youve got troublealso have a look at your power valve they can get clogged up youll see if it moves freely or not.If your going to go new piston look into a forged piston ie.wossner,weisco or something sililar theyll last so much longer than standard cast pistons so long as you warm them up properly of course

The current piston IS as wossner... Hence why I'm not replacing it. Cos it is ridiculous to replace a 10 hour old piston that has absolutely no signs of damage. If it had gouges and scoring I would've replaced it. I've put another 5 hours on the same piston and its still going very strong.