Piston Pin Circlips – nailed it

[AlexMember]

For the benefit of others and for when I do this again next time.

Piston Circlips done easy(ish) without the magical installer tool.

I’ve noticed people on the Net complaining about these clips and I’ve wondered what they were on about. Never had a problem in the past. Unfortunately the people of Vertex (and maybe others) thought it a great idea to put a step in the piston pin bore to make putting the clip in a nightmare. Easy to get them to the first step, a real shiiit to get the clip in the actual groove. Well after working out a good way to do it I was pleased enough with myself to share my approach.

Tools: Needle Nose Pliers, Number 2 or 3 flat blade screwdriver, plastic scraper tool.
[attachment=2281]Small_IMG_0004.jpg[/attachment]

1) I have the circlip opening at 6 o’clock. The opposite side insert is as close to the actual groove as possible.
[attachment=2282]Small_IMG_0005.jpg[/attachment]

2) Cover that part with the plastic scraper tool to stop the circlip flying out into your eyeball. Use the pliers to pinch the circlip ends onto the first step. Try not to scratch the hell out of the piston.
[attachment=2284]Small_IMG_0006.jpg[/attachment]

3) Finally with great care use the screwdriver to push each end further into the bore and into it’s groove. Photo shows the idea but without the ends being further in there (not enough hands). The smart cookies would have some rubber hose or heat shrink around the screwdriver to avoid damage on slipping. I was super careful holding the screwdriver with fingers close to the blade and piston.
[attachment=2283]Small_IMG_0007.jpg[/attachment]

Absolutely nailed it.

[Mick DMember]

Good one Axel, I am actually hoping that you aren’t re-using that piston though? :blink: :laugh:

[AlexMember]

No I won’t be. However, it’s not as bad as it looks. Jetting is a bit rich and there’s some cold seize marks from the last 2 owners. She has also sucked in some dust from a not-so-well-seated airfilter over the years too. It’s within spec still but considering the work to pull these 300s down and remove half the cooling system to get the bloody barrel off, I’ll pay for a new piston. Used to be much easier in the old days to do a top end.

[malleeMember]

Thats a go idea and another way to get them in as they can be a bit shi#y at times.
I will be like that tonight “Piston broke”:laugh: as going for a few birthday drinks with the boy’s.:whistle:
Mallee

[Richard WMember]

Nice on axel, My tip is to have the missus standing behind you as you put the clip in.

[AlexMember]

Hows this for dragging up an old thread. Had to search for this again as it’s been that long since rebuilds (1000 views). 5 years nearly to the month! The piston that came out this time was good enough to put back in.
Hopefully I won’t gouge the piston or lose the circlips on the floor….
Weirdly this time round I had to file the ring end gap. Never had to file a 2T ring gap down ever. Ring gap on genuine KTM rings I have are 0.25mm. The minimum gap for 300cc should be 0.3mm. SFA I know but the consequences would be disastrous.
Also, 200hrs without cleaning the power valve is a wee bit too long. Took me hours to get the carbon off the flapper. Didn’t even open up all the way any more.

[DeanMember]

axel wrote:

Took me hours to get the carbon off the flapper. Didn’t even open up all the way any more.

Thats because you only ride it around on the pilot jet!! :woohoo:

just Joking

Ollie

[AlexMember]

Ollie wrote:

axel wrote:

Took me hours to get the carbon off the flapper. Didn’t even open up all the way any more.

Thats because you only ride it around on the pilot jet!! :woohoo:
just Joking
Ollie

Not so Ollie. Although it is a 300 not a 125. I put a 38 pilot up from a 35 so should have even more carbon next time.
My helpful advice didn’t help with the second clip. F’n thing flicked out and hit me in the forehead. Luckily I wear safety glasses. I ended up using a different technique for the second one. Then lots of filing down high spots all over the piston LOL.

[DeanMember]

Hey axle you could try one of these, ive never hsd a problem,but others swear by them,

ollie

https://www.accu-products.com/accu-products-specialties/c-clipper-circlip-installation-tool-2-stroke-model.html?page=all

[AlexMember]

Cool idea. If there was money to be spent we’d be better off buying a heap of clips that have ends on them like Slavens uses in the U.S. Can use needle-nose pliers to insert/remove. Not sure if we can buy them here in AUS, but can’t see why not (unless they are $20 a pair…)

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