jetting a kdx200sr

[burmahiker]

I have a kdx200sr (1989 G1) and I am wanting to improve the jetting. The guy who had the bike before me had put a wire in the main jet (???) which I have now taken out. Since then it seems to have much of the snap taken out of it, but still has good bottom end. I run a 122 main jet with a 38 pilot jet and live at about 1000 feet from sea level. Its also very hot and humid here (Thailand) if that affects things as well.

Any help would be much appreciated! I am thinking of maybe going down to a 118 or 120 main jet, but am not sure if I should instead adjust the jet needle. (btw my carb is a 28mm which is standard for the sr's)

 

[19Brendan81]

Hey mate, I ride an SR too. I am in the middle of putting a 35mm carb on it as we speak. With my 28mm carb I ended up settling on a 115 main jet at altitude (3000 feet), and a 120 at sea level. At first I thought 115 would be way too lean, but it worked a treat. The heat requires leaner jetting, but if you start with something like you have suggested in you should notice a big difference in power. The temps here were 25 to 30 when I rode it with the 115. What temp is it up your way at the moment?

For info My bike has a stock pipe (gutted) and muffler, and has the airbox lid drilled out.

 

[burmahiker]

Thanks Brendan. I am a little lower than you, but much more humid and hot with temps at around 35 - 40. That means I could theoretically go even leaner except from the altitude right? Also, I haven't gutted my pipe yet, (have read its much more difficult to gut than a US kdx, comments on that?) but my airbox has a K&N filter and I ahve taken the "snorkel" part right out so I don't ride in the rain with it this way. :-) I think generally I could get away with about the same set up as you but want to be careful I don't cook my engine.