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Lean Condition - Help !

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1989 KDX 200 - Just bought for $250 off some woman that said it was her husbands and needed it gone. No information about the bike other than it was running before?

32:1 Mix with 93 Octane

1173n needle in Richest Setting (bottom slot) ((originally 1172n bent up))

168 Main Jet (originally 148)

68 Slow Jet (originally 48)

50F at sea level in Massachusetts

I just got done putting in the 168 and 68 jets taken off my 1982 KDX175.

With the original settings the idle was hanging so I swapped out my throttle cable from the KDX175 to the KDX200...nothing changed.

Was getting a lot of smoke and chased that down to the head gasket was no good. Changed it with OEM and also Permatex Copper both sides of gasket and smoke went away....but lean condition still exists.

Noticed the white milkshake in tranny, part arrives on Friday. So basically I haven't had a lot of time to diagnose this bike as I can't heat her up because I yanked out the old water seal and coolant is gushing into tranny now.

Back to lean condition. Today, before changing from the original jet set up...I noticed that if I run the bike with choke on, it seems to run better = the runaway idle was fixed = lean condition was the cause.

Decided to try and richen up the flow and put in the KDX175 jets 168/68 and left 1173n on richest setting. Left the choke on for about 1 minute....rich smoke coming out now. Throttle is responsive and doesn't runaway...nice.

After about a minute....I guess the bike warmed up enough as I turned off the choke and she was idleing and throttle response was good, no runaway.

Am I masking a lean condition caused by an air leak or could the prior owner(s) have increased the displacement? When I did the head gasket I guess I should have measured....however all I noticed where a bunch of numbers/letters on the piston but couldn't read well.

Any advice would be appreciated ! How long can you drive this liquid cooled bike without coolant in 50F weather....I'm just yard driving trying to sort out some of this lean stuff.....not going fast or taching high, just short runs, half throttle blips, etc.....bike is not scortching hot or anything.

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With 68/168 jets I don't see how it could possibly be lean. That is some hugely rich jetting, has to be an air leak somewhere.

Do you have a can of starting fluid (ether) setting around? If so, take the bike outside and start it. Spray the ether around all possible intake leak points and see if the motor speeds up all of a sudden when sprayed in a certain spot.

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