need carb tuning help on 85 kdx 200

[sfc crash]

we got the bike up and running. it's got the stock factory spec main jet and pilot, but it's a hard starter. if ya spray starting fluid in, it starts, and it idles ok. what circuit control the starting, air screw adj, fuel screw, air jet/ thanks for any help you 2 stroker you. ;)

 

[craig]

Have you verified that the pilot jet is completely clear? The hole in the pj is so small, it can be hard to get clean. It's not necessarily a good idea (you could theoretically enlarge the hole) but a small single strand of wire can be inserted through the hole, the you can hold the ends of the wire and 'roll' the jet (I roll it on my leg) to 'scrub' the jet.

What about compression? A bike w/low compression can be very hard to start.

good luck,
Craig

 

[MX175]

I just got an '85 running this fall. I put in a new 40 pilot jet. A 35 will probably be OK too. There is no airscrew to adjust on these mid-80's KDX's. Also check for cracks (leaks) in the manifold between the carb and cylinder. Because this bike did not come with a piston, I started with a new top end and it started on the third kick. Cleaning the carb and replacing old or discolored jets is always a good place to start.

Good Luck and let us know what happens.

Mark
'80 KDX175
'85 KDX200
'88 KDX200
'81 XS850 Special

 

[dirt bike dave]

With stock jetting, I could start my '84 by hand.

Until the stator started going bad. Then it kept getting harder and harder to start until it wouldn't start at all. Still showed a spark, but by eye it is hard to tell that the spark is weak.

The stator going bad is a common problem on the vintage KDX's. If you can't find any fault with the carb, I would look into having the stator rewound.

 

[sfc crash]

hey, you 2 strokers are ok. yeh i just replaced the stator, the coil, the reeds.my buddy just orderd the exauhst gasket and spacer, it was blown out. i'm wondering if that might be adding to it. i cleaned all the jets before we put it all back together. thing was, after putting it all back together, i sprayed starter fluid in it, started first full kick. thanks for the help.