Jetting

[vtraudt]

My 1987 KLR250 has always been difficult to start (hot and cold), bad over the last 2 years and virtually impossible during last summer and this year.
I bought a motor from another 87 KLR250 and installed it.

Took BOTH carbs to a local repair place and asked to overhaul them. they were soaked 24 hours, taken apart and checked.
Even so I told him, he did NOT put new jets in (didn't have in stock).
My book says:
Main Jet: 120
Pilot Jet: 35

He told me in both bikes installed is:
Main Jet: 118
Pilot Jet: 35

Said he increased the Pilot Jet a bit with small drill.

After installing the carb back on the engine, she started after a few kicks (still on the stand).
I installed a few more parts, bench, etc. and tried again. Nothing.

Then noticed I did not plug the connector in that plugs into the electric module with cooling fins right under the side of the bench (right side). Looks like a rectifier or something.

Plugged in, but still not starting (even with push start).

Since I had been messing around so much with choke, throttle, etc. (pretty much no standard setting worked for me in the past): what is the most 'common'  starting proceedure (cold and worm).

My spark plug was totally worn (and white, indicating lean).

He sold me a
NGK DPR8EA-9

Book says:
NGK: DP9EA-9

Not sure what the difference is between the 2. Do I need to get the exact 'book' plug?

What is the GAP?

[vtraudt]

Also found in factory supplemental book:
Plug alternative for Canada:
NGK DPR9EA-9 (normal: DP9EA-9)
Not sure what the difference is?

Gap: 0.8-0.9mm
0.8mm: 0.0315 inch
0.9mm: 0.035 inch

[vtraudt]

Had the carburetor checked by shop (soaked, cleaned, disassembled, adjusted, etc.).
Put back on the bike (had bought and installed a used motor; ran fine, good compression, no valve noise).
Brand new NKG plug, gapped to 0.8mm.
Kicked it while on the stand. Started, sounded really good, ran for a minute or so.
Let her cool down and completed the bike.
Tried again. Nothing.
Push start. Nothing.
Tried again today. Nothing.
Checked spark. Yes.
Tried kicking and push starting with and without choke. No throttle, bit throttle, medium throttle, wide open. Nothing.

What could be wrong?
Possible I connected the fuel lines wrong?
I connected fuel to the lower of the 2 elbows on the left side of the bike/carb, the one facing forward.
The top to an overflow tube.
Bottom drain to overflow tube.

Wrong?

If NOT wrong: could it be that the choke slide is not seated properly?
Other suggestions what to check?

[Becker]

What's your valve lash? I didn't see you mention it.

The valve lash on the 250 is .008"-.009" it's very easy to check and set.

Out of spec valves usually cause hard starting. Typically they get tight with use. I accidently had mine set loose once and had one hell of a time starting my bike. It would barely roll start.

Here is a link to a 250 valve adjustment. http://home.earthlink.net/~klr250informationexchange/toolkit.htm

Secondly, have you tried using a shot of WD-40 or starting fluid? If I ever have a hard time getting something running I'll use WD-40 in a pinch.

Try that stuff and report back.

[MrBob]

 You didn't mention a wet or sooty plug after your starting efforts. Do you know that gas is reaching the plug? The carb settings you list should not keep the bike from starting and neither should the heat range plug you list. Drilling jets without using a dyno or O2 meter is not such a good idea.
 Back to the basics: kill switch off, fuel petcock open with a good flow of gas, blue spark to the plug when you kick it, fuel to the plug when you kick it. Valve lash within specs. Are you sure the float level is correct?
 The choke should slide freely. It's easy to pop it out and check the action but even if it wasn't working at all you should still get some signs of life from the engine.

[vtraudt]

Had her back to the shop and got her back, starting GREAT (he drilled open the idle jet a bit) and idled well.
That is: for about a week.
Now she still starts and runs great, but idle is all over the place.
Either wayyy to high (3k) or she dies. Sometimes stays for a while at 3k, then drops and dies.
When, bringing down the idle with the manual set screw on the carb lowers it, but then dies.
When to low and holding her, adjusting the screw to bring into the 1500 rpm range works a a minute, next time WAY to high again.

I really don't want to take the carb off again (so happy to finally got the carb to cylinder boot on good and tight (used steel wire to clamp, since hose clamps did NOT work).

I already ran a can of seafoam with the last tank. No change.

Any suggestions?

[MrBob]

 Have you checked your cables for binding? Does moving the handlebars from side to side effect the idle? Is there a little play at the cable ends where they fasten to the carb?
 If the cables are good I'd be looking for an air leak. You'll need to re-examine the boots. Also, remove the boot on the air filter side and feel the movement of the piston for free movement, and a diaphragm with a hole in it will prevent stable piston movement. Check your idle mixture screw again. Of course, it's much easier to do this with the carb off. 
 Won't the shop consider this warranty work considering their recent work on it?
 Forget getting anywhere with the idle screw.
 This is an annoying development but probably not hard to fix.