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144 08 top end questions

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Never braved a top end before so I need a few questions to put my mind at ease!

I've noticed that on all the ktm engine views, that the bike has a piston with 2 rings. But the wiseco piston I've bought only has one. Is that an issue?

Gapping the piston ring? Is it important or will measurement be correct already?

Been reading a tutorial, and dimension X has been mentioned. I'm really struggling to get my head around it?

Any other tips will be greatly appreciated, thanks!

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Never braved a top end before so I need a few questions to put my mind at ease!

I've noticed that on all the ktm engine views, that the bike has a piston with 2 rings. But the wiseco piston I've bought only has one. Is that an issue?

Gapping the piston ring? Is it important or will measurement be correct already?

Been reading a tutorial, and dimension X has been mentioned. I'm really struggling to get my head around it?

Any other tips will be greatly appreciated, thanks!

I have a topend pictorial floating around, possibly in the FAQ, and I have a PV pictorial in the FAQ that will help you. They are for a 200, but the information is the same.

Often the SX's come with 1 ring, shouldn't be a big deal.

I would check the ring gap to make sure it is within spec. You will need a feeler gauge.

X dimension simply refers to the relation of the piston at TDC in relation to the top of the cylinder, or bore.

Zero X is optimal which is top of piston at TDC = top of bore of the cylinder. You control this with the base gaskets. thicker base gaskets raise the cylinder, thinner ones lower the cylinder. Lowering the cylinder a tad increases compression, lowers the port timing and increases power, to a degree.

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Could I just re-use the gasket to save the complication?

You wouldn't happen to know what the clearence is meant to be?

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Could I just re-use the gasket to save the complication?

You wouldn't happen to know what the clearence is meant to be?

No, don't try to reuse the gasket. New gaskets will come with the gasket kit. The Moose kit is nice as it gives you a couple of gaskets. Put the jug on with both gaskets in the kit and check to see where the piston is in relation to the jug.

Set X at 0 or as close as you can get it. There may be something in the manual as to where to set X.

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Use the thinnest base gasket you got and I bet you are as close as your going to get. Without buying more base gaskets.

Joe...........

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I have 3 base gaskets so I'll use the thinnest. Dimension X is 0.10mm for the 2010 model, it won't be any different for my 08 will it?

Really struggling to find the piston ring clearence for my bike. Anybody know what it is?

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The majority of the 144/150's require at least a .75mm base gasket to get the X dim set to zero. Measure the squish, Ideally on a 125/150, squish should be 0.7-0.9mm. Don't use the thinnest gasket, and call it good. Do it the right way, measure. All sx models come with a 2 ring VERTEX piston starting in 2008, I believe. Put a double ring Vertex in it.

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The majority of the 144/150's require at least a .75mm base gasket to get the X dim set to zero. Measure the squish, Ideally on a 125/150, squish should be 0.7-0.9mm. Don't use the thinnest gasket, and call it good. Do it the right way, measure. All sx models come with a 2 ring VERTEX piston starting in 2008, I believe. Put a double ring Vertex in it.

Pistons already bought so I can't do that. Hoping this single ring will be ok

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Pistons already bought so I can't do that. Hoping this single ring will be ok

Be sure to warm it up every time, Wiseco pistons are good, you'll be fine. Put a Vertex double ring in it next time.

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I did the first top end on my bike recently and i was in a time crunch - i wanted to race that weekend. i layered up gaskets and it worked out fine, i don't remember what the thickness was tho. pretty sure i did 2 .25 and 1 .50 - my boyfriend is a tech at a shop and it worked out fine. it was VERY easy to do.

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