I just bought my very first motorcycle, a 2006 KLX 250. Zero experience with motorcycles - both riding and mechanically.

I bought it from a very reputable dealership but I still may have been an idiot due to inexperience.

I do not have an owner's manual or service manual for it, so I'm relying on a Cyclepedia subscription and online searches - which is pretty good but still missing some things.
OM is in post, but may end up having to buy an OEM SM at a ripoff price since 2006 manual isn’t on eBay and I can’t find a PDF of it anywhere.

One of the two previous owners appears to have already done some things to the bike:

• 13t front sprocket (yay!).
• KDX Snorkel replacement
• Kouba 2" lowering links (reserved yay - a little afraid of warnings that 2" compromises bike and 1.25" is safer, but I'll be taking it easy for a while since I'm a beginner)
• Removed radiator fans to fit on aftermarket tank (which I have as an add-on that I do not plan on using)…
  Unfortunately fan did not come with bike so I'm having to put one on from eBay. Still need to find correct screws for it, OEM ones are ripoffs.
  
• Possibly desmogged the bike? I am not sure. There's a tube that just dangles from the airbox all the way down past the rear shock, close to the kouba links. Can't find it on part schematics. What does this do? Maybe oil seepage type tube that doesn't have any catcher type thing in it?
• Has aftermarket Supertrapp exhaust pipe with lame packaging tape around connecting end. Doubt I’ll use this, either, since I’ve only found one post even mentioning Supertrapp for KLX250. Also like my pipe being quiet since I plan on using this bike primarily for dirt trails right up against neighborhood, and I’ve read reviews that say stock pipe is actually better than a Supertrapp. Anyone actually have a Supertrapp for KLX250 and recommend it? Saw an old post from Mustang(?) but no impressions after the fact.

So here’s my concerns that I’m hoping some of you fine fellows and gals can help with:

1. Title transfer from 2011 (from 1st owner to PO) showed 2,721 miles on odometer back in 2011.
   I bought the bike with 2,600 miles on odometer here in 2014! WTF?
   
   When I did an online VIN check nothing fishy came back (no salvages or insurance claims or anything weird).
   Maybe PO replaced speedometer cluster?
   
   Actual PO was dealership owner’s father and used it as an RV bike and didn’t use the aftermarket gas tank or exhaust pipe, either - and supposedly took good care of it maintenance-wise, and sold it due to getting too elderly to enjoy offroading anymore.
   I’m trying to get some answers from dealership on this one but they seemed to be unaware of mileage discrepancy.
   
   I don’t think they were trying to pull one over on me - they just hadn’t compared title to odometer (and they were selling it on consignment originally).
   FWIW, bike seems to be in pretty good condition and runs pretty well for me (I think).
   
2. Gasket air suction valve cap appears rusted. What the hell does the gasket air suction do, and is the cap important? Google has yielded me zero useful results. If it rusted completely out and dropped rust flakes downwards, what would that do? I’m referring to part 11065-1190 on this page: 2006 Kawasaki KLX250 (KLX250H6F) Cylinder Head | MRCycles
   Attaching pic as well in case I’m wrong on what part it is.
3. If PO ran the bike for a while without radiator fan at all on RV trails, should I be concerned about damage from overheating? What's the easiest way to tell if overheat sensor is working (to get temperature warning light to come on?).
   
4. Idle seems a little rough. Not as bad as some videos I’ve seen - it seems to “hunt” for a stable RPM and varies between ~1300 to 1500 every now and then. Even after warming the bike up on a 20 minute ride in 90 degree heat in Texas it still stalls somewhat easily in 1st gear and doesn’t have a smooth/stable idle. Maybe this is me just being a newbie and not working friction zone right with clutch, too? When it does stall out, I quite often have to pull back the throttle when I hit the start button to get the engine going again - just the start button by itself may not start it back up, even though I don’t have to do this from neutral when I first start up the bike. At speed and any RPM higher than say 1800, engine seems very stable, but I've only ran it up to maybe 35 mph at this point. What should I do here? Can old gas cause this, and seafoam by itself fix it? Should I clean carb/rejet/install Kouba extended fuel screw and adjust fuel/air ratio, etc? It's not producing black smoke so I don't think it's too rich, and it's not popping on decel, so maybe it's not too lean?
   
5. How doable is a carb dynojet install for someone with ZERO mechanical and motorcycle experience? I've found some good resources (like the HMF install guide), but still not quite enough for me to dive in with confidence.

Sorry for the wall of text and appreciate any help I can get. I plan on being around for a long time (this will be my only bike for several years most likely).

 

First off, welcome and congrats on the bike!
There is a manual here in the Sticky section, along with all sorts of mod info and links to threads about them. Lots of good how-to's to help you decide if you can do something, and when you do and it goes wrong, there will be help from forum members.
The pic of the rusty part is the bolt the PO stuck in where the air injection system went, it was EPA smog crap that you don't need. As long as it doesn't leak you are good.
As to running without the fan, you should be alright, as the fan only comes on when running slow and hard (off-road) if things are good. Couldn't hurt to change the coolant, though.

 

Welcome Zeno.. Your carb may have a DJ kit in it already - or other such re-jetting - as it runs way too lean for any "uncorking" to be successful. Your symptoms would seem to indicate that the primary circuit on the carb is not functioning correctly. This could be improper idle mixture screw setting or clogged up internal pathways.

 

There's no manual for the 2006, just the newer ones...
Thanks for the info on fan!

 

Excellent! So maybe I should just get the T-screw and do my first carb clean? Thanks!

 

So I actually got to talk to the PO on the phone...

-He didn't just change the engine sprocket to 13T, he also changed rear sprocket (but not sure what he changed it to).
-The odometer reading is no worry - when he bought it from a widow, they were at title office doing paperwork and the widow misremembered the mileage on the bike
-He didn't put in a dynojet kit, but he did change which notch the pilot or main jets were on or something? May have swapped out one needle. May not have understood what I was referring to when I mentioned dynojet.

 

If you must keep the bike very quiet then there is not much power improvement to be had. You are not a candidate for the MCM according to the information on the MCM thread - meaning you already have superior cam timing. I only have experience with the FMF Power Core 4 and the DG-R slip-ons - both are loud but both will let you tune the bike for 20 hp - perhaps a little more.

 

Hi,
You can probably fix the struggling idle by adjusting the air screw.
Leave your stock exhaust on, I did, it is nice and quiet. You want an extra 1/2HP & have to put up with all that noise?
If you need lower end torque, put a pumper carb on.

 

There are notches in some needles, like the dynojet and Kawi N1TC models, that let you adjust now the throttle behaves from about 1/4 to 3/4 throttle opening. The stock klx250 needle does not have notches so no adjustment possible (except that some riders shim it up with a small washer or two). There are a number of riders who get the N1TC needle instead of going dynojet. There are also other outfits who re-sell the dynojet kit under their name (Moose is one IIRC).

The pilot and main jets themselves don't have adjustable notches.

 

Your implying that our uncorked Stage 2 KLX's only gained 1/2 hp ? Dems-is-fightin-words...LOL Hey, how about getting your stock exhausted KLX dyno'd and set the record straight...?