Piston circlips

[cheapo]

In the process of finishing a top end rebuild on my 2000 kdx 200. When I put one of the new circlips (snap rings) into the side of the piston, I did not line it up so the ring opening didn't coincide with the notch in the edge of the piston pin hole (i.e. the opening and the notch incorrectly line up). No matter how hard I tried, I could not slide it to make it correct. The circlip was put in with minimal compression so it is very tight in the groove. I want to limit the gouging I put in the side already so does anyone see this as a big problem before I button up the top end? Hope I explained my problem clearly. Thanks all.

 

[Coolector]

No problem man

 

[Bizerk]

Hhmmm...I don't entirely agree with the "no problem" feedback. Circlips do not necessarily have to be at 12 or 6 o'clock but their openings should not be at the grooved opening on the piston. I just finished rebuilding my 2000 KDX 200 with a Wiseco piston. I put one end of the circlip in the groove but opposite of the opening, used a pointy thing err.. scribe-awl thingama and worked it into the groove. Then used a small flat bladed screw driver to make sure it is completed seated. This is very important above all else...make sure it is seated all the way around in the groove

 

[Robcolo]

Hhmmm...I don't entirely agree with the "no problem" feedback. Circlips do not necessarily have to be at 12 or 6 o'clock This is very important above all else...make sure it is seated all the way around in the groove

BUT, the clip opening should never be past the 5 or 7 [11 or 1] o'clock position - unless you just happen to have a spare $1000 laying around for a new engine. Piston acceleration WILL pinch a circlip closed and it WILL come out. And, as twistid said, there's been a large number of posts on here where an improperly seated circlip has cost the owner many hundreds of $$$$$

 

[cheapo]

Completely understand the concerns. My problem is I can't spin it in the groove. After an hour and a half with a flat head screwdriver, awl and small needle nose, I succesfully scratched the area around the wrist pin hole, but the circlip did not budge. I even heated the area slightly hoping that would help, but to no avail. Like I said it was put in with minimal compression, it is completely seated in the groove and appears to be tight. If anyone has any suggestions on how to slide it, I'm all ears. Otherwise I'm at a loss on how to adjust it. I hate to say it, but may take the chance and run with it. Thanks again.

 

[outrgus]

Would it not be cheap insurance to take the clip out and replace with a new one that's installed correctly? A one dollar clip compared to a cylinder and piston is cheap insurance for not having a failure.

 

[Peer Lovell]

You shoudl be able to move the clip with a pair of fine needle nosed pliers. I have been throwing my circlips in where ever they land, then ajusting them to 6 or 12 o'clock for 40 years, with never a problem. You need to pull the clip down just a hair to clear the groove, if this makes sense. I wouldn't start the bike unless I got them in correctly.

 

[skipro3]

I've never seen a condition where it was shown that piston acceleration could pinch a new circlip closed enough for it to come out of it's groove. That would have to be one weak circlip, most likely a used one, or one not provided by the piston manufacturer. Never reuse a circlip for any reason. If you can't get yours to slide in it's groove to the 6 or 12 o'clock position, there's something wrong and you need to pull that clip out; and if you pull it out you need to replace it and not reuse it. Do you still have the old piston assembly? Take a look at it and see why that one isn't hanging up. Mic the groove and clip. Maybe something mismatched there?

 

[cheapo]

Thanks for the responses. I am more than willing to replace the $1 clip with my many spares, problem being I can't grab it. The notch allows an area to get pliers in there to pull the clip, but if the opening in the clip lines up with the notch, no place to pull the clip out; that inlies the problem. Any suggestions on how to pull out a fully seated clip with no place to grab on? Man, how frustrating can a $1 piece get!

 

[skipro3]

If you can pull the other side circlip and remove the wrist pin, then take the piston to someone who has a machine shop, maybe they could get it out?

 

[cheapo]

At the risk of asking a stupid question, why is there a better chance of the circlip coming out with the notch and opening lined up vs not lined up (assuming the clip is seated correctly)? Is it strictly related to the 6/12 o'clock positioning of the clip?

 

[Bizerk]

There have been several conversations on this circlip thing. I certainly am not arguing with anyone here but from several other people have said that there is no proof or backing to the 12 or 6 o'clock rule only to make sure that it is not located at the opening of the piston groove.

I have also never heard of a circlip compressing enough or at all to cause it to pop out as mentioned above. Just my 1/2 of a shinny penny from a MMI graduate...but what do I know. :think:

 

[canyncarvr]

What's a shinny when used in regard to pinny?

Interesting that the first responses completely miss the point of the post....anyway...

What's the window..probably around 4 o'clock? That's a bit too far around for peace of mind. Probably not worth destroying a piston over, though (with digging and gouging, cussing and griping).

Seems the clip end space fits rather perfectly with the window. Neat design!

If you consider it enough of a worry to have get it out the piston is soft enough to get a sharp scribe (an awl may not be sharp enough) under the clip to raise it enough to pry it out. Probably cause less damage than has been done already. Watch the pressure applied sidewise.

Of course, keep the crankcase covered...and do use a new clip.

...the little buggers. I had to call my daughters in for the clip-hunt saturday when in spite of my best efforts at prevention the thing STILL went s-p-r-o-i-n-g and landed a long ways from where I was sittin'! Heck, that was on the easy clip...the one put in with the piston sitting in your hand!!

I couldn't find it. A seven-year-old did, though! Bless her heart!!

 

[KX02]

Here's my .02 Dollars. As has been stated, I've always been able to move the circlip fairly easily in the groove until the last top end job I just did. I used a Vertex piston and they use some VERY strong circlips. I had a hard time putting them and I could not rotate them either. I figure since they are so hard to move they should be OK. I haven't ridden yet but the engine has a good 20 minutes or so of time idling and it's OK so far.

 

[cheapo]

I tried getting under the clip with the awl but no luck (may have not been sharp enough though); but was also worried about the damage I was doing to the piston. By the way, the piston is a new Pro-X. At this point I will give it another try to pull the clips and then make the call whether to run it if I'm unsuccessful. Thanks for all the input.

 

[canyncarvr]

With a scribe (mechanic's scribe) you should be able to snik under the clip without causing huge damage. A scribe is very pointy, though.

You have the piston off the rod? You could get a better angle on the thing if you had the piston on the bench.

 

[cheapo]

I have to take it back off the rod. Problem I was having is getting a good angle on it. The clip is recessed in a ways and it was difficult to 'pick' under it. Do you see a problem with too much gouging of the piston? even picking under the clip to pull it out? just thinking of too much 'mass' off one side of the piston than the other; or stress fracturing of the piston if I pick at it too much.

 

[89kdx200rdr]

you heated the piston pin snap ring? go to sears get a machinist's scribe and pull the thing out. if you messed up one side the other side should be good take it out go buy two snap rings and pay attention next time or dont drink and maint

 

[canyncarvr]

You don't want to be putting much (none is good) side-wise pressure on the rod.

re: mass and fractures.

I wouldn't worry about it. But then, I'm assuming no sledges will be used, no pounding will be done and no angle grinders will be used to improve access angles to the clip.

:think:

 

[kdxfreeeek]

k now im scared i just finished mykdx top end and i didnt check that what should i do

 

[canyncarvr]

An ounce of prevention is worth a pound of cure.

The ounce is taking the cylinder back off to check.

You might be up for a pound by starting it up, going for a ride and seeing what happens.

Sorry, 'bout that. :(