My Squish Problem

Jared Langenfeld · Posted: Sat Mar 10, 2012 12:41 pm Post subject: My Squish Problem

Alright, when I bought my kart at the end of last year, it was a spec-Honda built by Jim at CKT. I decided to go with a mod head and domed piston for this season to make some more power, and there was a guy here on ekarting that was selling a mod head that was machined by Swedetech. So I picked it up and bought a 2005 piston.

I finally got around to putting my top end back together today and knew my squish needed to be between 0.030" - 0.035". I also ordered several thicknesses of base gaskets (0.0015"-0.020"). So I put my top end together with no base gasket to get a baseline reading of squish. When I went to turn the motor, it seized against the head. Crap. So I put the 0.020" thick base gasket and I measured a squish of 0.024". I noticed the thickest base gasket that FasTech sells is 0.020", can I use two base gaskets or is that a bad idea to get the required amount of squish?
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2008 Mike Wilson with Honda CR125 shifter

Chris M Johnson · Joined: 14 Oct 2005 Posts: 568

Jared,
You can stack base gaskets, but if the cylinder ports have been raised (the head is machined so that it intrudes into the cylinder space, you will be best served by a custom aluminum base gasket, which builders can sell you. The process of setting squish involves inserting (adding) gaskets of various thickness to reach your target. I don't know if there is an accepted maximum, just that in my experience, cylinders that have stock or lower exhaust ports dont need the aluminum spacer. You can buy various thickness gaskets, all the way down to .0025 from Empire Karts. Good luck.

Chris

Christian Hubbell · Posted: Sat Mar 10, 2012 2:50 pm Post subject:

I have an aluminum spacer and at least 5 gaskets on mine right now. Very Happy

I spray them with a little copper gasket spray before assembly and torque to proper specs. Don't forget a retorque after the first warm up too.

Jared Langenfeld · Posted: Sat Mar 10, 2012 3:18 pm Post subject:

Thanks for the input. The previous owner of the kart gave me the invoices of the work done by CKT and one of the line items says "labor to build 125cc STOCK CLASS". The previous owner said he bought the motor brand new from a Honda motorcycle dealer and then had CKT install it on the kart. It looks like all CKT did to the motor itself was plug the power valves. It looks to me like a 1999 cylinder with no port work.

I just got back from the garage and I have a 0.020" and 0.015" base gasket installed and now I'm getting a 0.032" squish after a couple of measurements.
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2008 Mike Wilson with Honda CR125 shifter