Ktm 144

[elf]

Can someone help me get this motor running good. Its a Eric Gorr 144cc ported for low mid . It has no low end no top and no hit. Just a surge in the uppermid.Ring gap is .20 thou. squish band at .45 thou. Using C-12 race gas. I have spent manny hours trying different jetting combinations. Right now it pulls about as hard as my friends stock 02 yz125. But his bike has more bottom and more on top. I have spent a lot of time and money on this bike any help would be much appreciated.

 

[Jman271]

What yr bike is this? What jetting were you running before? How was it running before? Are you sure that the pv is working properly?

 

[Glitch]

I would see if the power valve connected properly, because that can make a big difference. For jetting, are you sure that it is good? Because if it's lean then that might explain no power.

 

[elf]

Its a 03 ktm. The power valve seems to be working. I took off the pv vent cover started the motor reved it up and could see the valve moving up and down. I jetted the bike stock with race gas and had it running really good. Now its jetted the same except for larger main jet. The needle seems to be the most important jet. Too lean and it will not pull the next gear under load like going up a steep hill. Too rich it sputters before the main jet takes over. I have three needles that came with the bike and none of them make the bike run the way it did stock. Maybe I need a different needle.

 

[Jman271]

Try a 1468H needle in the middle, it is a kawi needle, but it is a big improvement. They are about $15, if you want to go the cheaper route, go to www.sudco.com and get the DDJ, it is the same needle in the 2nd position as the 1468H is in the 3rd,,,,but, it is $5.50. You will have to go fatter on the pilot and up on the main. I have a mod 03 125sx that will holeshot any mod 125, if you need more help, let me know. I am running 195 main, 55 pilot, DDJ 2nd, factory fatty, and v-forvce, mild porting, and 1mm squish. This bike is scary powerful. The 144cc kit will run a bit diff than the 125, but they are the same bike beside the displacment. Let me know, Jman@myeastern.com

 

[Jman271]

Also, the "z" dimmension for the pv flapper should be 43mm measured from the top of the barrel to the bottom of the flapper. This is the baseline setting and can be adj, if you went w/ a diff base gasket,(KTM makes 6), you could have way to much squish. Let me know about the pv flapper, I'll explain how it is adj,,,,,,

 

[GREENBUNCH]

You guys are missing the obvious here. Maybe the Eric Gore job missed the target. I had a 212 kit done by Eric for my 200 MXC with more everywhere porting. I spent months jetting and even sent it back to Eric because I could'nt get any mid range out of it, just bottom end. Bottom line was I bought a new stock cylinder from KTM and it runs great. I did have good results with EG's work on a Yamaha YZ144. Very happy with that combo, just poor results with the KTOOM.

 

[MikeS]

Too much low is real possible. Our TM was that way. I ended up adding a thicker base gasket and different exhaust to round out the power.

The no low end can be jetting. The bike will not have the topend or upper mid range of a stocker.

I plan on another 150 TM kit shortly and I have already told eric that we want better low if possible but mid range and over rev are a priority. He said the original intent of the 144/150 kits have been to make the 125 easior to ride by adding lowend.

 

[bclapham]

i think a low to mid port job is a bad idea on any 125 etc, especially on the 144 since they should have quite some more bottom anyway. Maybe you can get away with what fastwes has talked about and take the epoxy out of the cylinder and maybe a thicker base gasket???

that said, mess with the jetting as much as possible, remember C12 runs really rich. Also, steve-125's tip about getting quite agressive with the timing advance might help also

 

[bclapham]

here is some more reading

http://dirtrider.net/forums3/showthread.php?threadid=79626

http://dirtrider.net/forums3/showthread.php?threadid=78690

http://dirtrider.net/forums3/showthread.php?threadid=77809

 

[SFO]

My EG 212 with more better is a rocket sled.
None of my friends 200's run as well. (all 3 of them)
I think there is another issue here.
Just my experience.
I did have to do the whole powervalve adj via the manual though.
I hope you are able to get to a happy point with your mods, what else has been done?

 

[MikeS]

Elf

try the needles suggested here and drop the main a size or two with the stock needles..

Typically the big bore wants richer pilot and leaner main in many cases.

C12 will be a Tad rich, you said it is the same jetting as stock with the C12 but a larger main. I suspect that is part of the issue. Go with a single taper needle and the stock main jet. The single taper by design will choke off the main jet a bit automatically.

Our TM responded well to a CEK needle 180 main from the stock NOZG 185 combo. Junior said it woke up the bottom to mid transistion and revved OK. We ran c12 also.