new tools

[Paul_E_D]

I bought a deck height tool and a dial guage to help me set up my new KTM. I found I had the piston .25MM too high last time, and I'm sure that's what cause my over heating. It increased compression and decrease squish causing it to run a little hot.

I put another gasket under the cylinder to raise the deck. I didn't have the optimal combo of gaskets, so I erred on the side of caution. Might lose a little snap, but it shouldn't run hot. I can probably even run pump gas. I did put a smaller insert in the head to gain back a little compression.

I can't wait to hit Crow hill with it again...

[rebelpacket]

Paul, can't you simply use wax to check for the squish?

I've never seen a "deck height tool", what are they?

[Paul_E_D]

Yeah, but squish is not the only thing to consider. Deck height should be set FIRST, then squish can be adjusted through headwork.

[KB]

Squish? Deckheight? Whatchoo guys talkin bout? I am going to do a top end on the KTM this winter and what is this talk about this stuff? Please fil me in!

KB

[SSearchVT]

Take a look at the plug, make sure it is the right heat range. Then make sure it is coming out a nice toasty brown color. A lean condition for the jetting will make the bike run hot. If you haven't done it already - make sure the waterpump is working. It doesn't take much to break those little plastic impellers, or air bubbles in the line that need to be burped out. Another one I've seen is to make sure the gaskets are on right. A lot of times they can go on backwards or upside down and block off water passages. Did it start to overheat after a rebuild? Hope this helps.

[Paul_E_D]

Yah, I've covered the basics. I had put a new piston in without the deck height tool and this is all non stock stuff. I measured it after that over heat and the piston was a little high. Since I reset it, I've had no probs. I'm still rich and gonna lean it down one more step this week.

KB, When you put a new piston in it's wise to set the deck height to zero. That means the piston doesn't protrude at all over the cylinder, and it's also not recessed at top dead center. There are many thicknesses of base gaskets available to help you acheive this. (we're talkin 2 strokes here right?)

Also, you could check the squish by putting some clay on the outside edes of the piston, putting the head on, and turning the motor once. Take out the clay and measure the thickness. it should be 1mm for stock stuff.

If deck height = 0 and squish is greater than 1mm, you can mill the head by however much you're over 1mm.

This will give you the most power out of bone stock parts. It will also run really well once jetted.

[KB]

Yah, I've covered the basics. I had put a new piston in without the deck height tool and this is all non stock stuff. I measured it after that over heat and the piston was a little high. Since I reset it, I've had no probs. I'm still rich and gonna lean it down one more step this week.

KB, When you put a new piston in it's wise to set the deck height to zero. That means the piston doesn't protrude at all over the cylinder, and it's also not recessed at top dead center. There are many thicknesses of base gaskets available to help you acheive this. (we're talkin 2 strokes here right?)

Also, you could check the squish by putting some clay on the outside edes of the piston, putting the head on, and turning the motor once. Take out the clay and measure the thickness. it should be 1mm for stock stuff.

If deck height = 0 and squish is greater than 1mm, you can mill the head by however much you're over 1mm.

This will give you the most power out of bone stock parts. It will also run really well once jetted.

I completely underdstand now. Yes we are talkin bout 2 strokes. Thanks for the info Paul. I had no idea about this stuff. I thought you just slap it together and go.

Good info and if anyone knows about 2 smokes it's definitely you 125 guys.

KB

[Paul_E_D]

I completely underdstand now. Yes we are talkin bout 2 strokes. Thanks for the info Paul. I had no idea about this stuff. I thought you just slap it together and go.

Good info and if anyone knows about 2 smokes it's definitely you 125 guys.

KB

You CAN slap it together and go, but depending on the base gasket you choose, you could end up with an overheating bike prone to detonation (or seizure), or a serious dog. with 2 strokes, a little care on assembly yeilds some sweet results...