Hi, and SMOKY

[paab]

Hi there, I just signed on to this site. A little about me: I'm an MSF instructor, expert roadracer (GP125), and a teacher.

I just borrowed a KDX200 for the fall riding season here in MA. It's a stock 91 in OK shape and has been sitting for a few seasons. I took it for a shakedown ride today, and I love it, but...

It smokes like a forestfire when I get on it hard. I'm using Maxima synth blend pre-mix. I never see this kind of smoke from my 125 racebike even with castor oil. I assume this indicates the need for a top end?

Also, a fair bit of fuel/oil drips out of the airbox and the tip of the exhaust. I'm pretty sure it's stock, so why would it be so rich?

Anyway, I'm going to start buy opening the cab to see what's in there, but any advice would be appreciated.

If this is in the wrong section, let me know, there's kind of a lot here...

Paab

 

[paab]

Hi and SMOKY

Whoa, sorry about the double post. This forum is a little bigger than what I'm used to. I wasn't sure if the KDX are was really connected or not...

 

[oldguy]

The Bike is jetted rich hence the heavy smoke, and dripping. Also could be burning up some varnish if it has been sitting for awhile without the fuel being drained.
Have fun on it

 

[Chili]

I merged your two threads and Moved them to the KDX forum, please don't cross post the same questions in multiple forums.

 

[paab]

Yeah, I figured it was rich, but I'm pretty sure it's stock. I'm going to go through the basics, but I don't have a manual. What's a reasonable main to use in MA?

Paab

 

[Ryan12833]

you cant tell unless we know current temps, altitude, mods and so on.

 

[strider80]

Pull the jets and see what you have in there now. I would guess a good starting point is a 155MJ and 45PJ, but the details are important as Ryan said. Do a compression test to check the top end.

 

[Jaybird]

Study up on the proper fuel metering of a 2T engine and all your questions will be answered.

You will learn that there are many variables to consider when metering the fuel for the optimum burn, such as altitude, ambient temps, relative humidity, level of riding, etc..
This being the case, there is no way that stock jetting can be valid for all. It is simply a baseline that the factory places in them. More often than not, factory jetting is set very rich.

 

[paab]

Ugh, I'm well studied in the area 2 stroke tuning. I'm about to win my first expert championship on the 125 roadracer. I'm doubting that this bike is anywhere near as sensitive to climate changes as my full race motor that runs at 14:1 compression.

I assume that one or two jets would likley suit the climate around here for most play riding, but are you guys saying you jet for each day? That seems excessive for such a mild motor.

I ride in areas from 1-3k feet. I found I have a 150 main and a 48 slow jet. I'm doing a top end and cleaning the KIPS this weekend. I'll just leave it and see how it looks after that work is done.

 

[kelseybrent]

Yes, 2 sets of jets cover my riding season pretty well.

Here's a good starting point for jetting, click
Factor in all your studying of 2T metering and you should be set ;)

Jaybird comes off as condescending, but thats only because he is.

Enjoy.