KLR650 Hard starting when hot

Recently bought a 2003 KLR. Love the bike but it almost will not start when hot or warm. Takes 30 seconds to one minute of on and off cranking with choke on and off before it finally fires. Worrying, embarrassing, and potentially dangerous.

So far I've tried: cleaning the carb and soaking the jets in cleaner overnight. All orifices were clear and carb did not look gummed up. Replaced the diaphragm as I tore the old one. Replaced the plug and changed the oil. Checked the valve clearances and all were in-spec. Replaced the vacuum hose from intake to petcock and replaced the fuel line and removed the in-line filter. The vent hose is clear and free of blockages, but only about 5" long.

There is an issue with the clutch lever switch as it will not allow starting in-gear with lever engaged, but this is not it as the bike will fire eventually. When in N and you engage the lever the bike will not start. Maybe polarity is reversed. Need to fix this to be able to start in-gear.

Any ideas from you KLR guys out there regarding the starting or clutch lever? Thanks.

Have you drilled the plug covering the pilot screw to open it abit, richening up the mixture?

Yes, the pilot screw cap/plug had been removed and the screw is backed out 4 half turns. I am running out of options and think I've done everything there is to be done, short of replacing the carb. Will check ignition timing and have a look at the spark.

Sorry, I don't know then. I'd ask on advrider or klrforum. There's not a whole lot of klr owners on this forum. If you find out, it'd be nice to update this in the future.

It might seem odd but check your gas tank vent. When your bike doesn't start, pop the cap open on the gas tank and try to determine if its sucking air then try starting it again.

It shouldn't ever suck air. If it is, your vent line is clogged or pinched.

Is your bike a California model?

Float level too high? I suspect it may be, then as you shut it off, the carb absorbs engine heat, fuel expands and may end up inside the carb/engine. But an overflow stand off tube in the bowl should dump this extra fuel. Make sure that bowl drain line is in tact. The overflow drain wil be at the bottom of the bowl.

It might seem odd but check your gas tank vent. When your bike doesn't start, pop the cap open on the gas tank and try to determine if its sucking air then try starting it again.

It shouldn't ever suck air. If it is, your vent line is clogged or pinched.

Is your bike a California model?

I second this. My 09 (Ca model) would overflow into the charcoal canister and REALLY be a bear to start. There is a small "pump" to the canister which seems to be prone to failure. Ditched the canister with tips from another forum. More better!!:smirk:

Yes, the pilot screw cap/plug had been removed and the screw is backed out 4 half turns. I am running out of options and think I've done everything there is to be done, short of replacing the carb. Will check ignition timing and have a look at the spark.

4 turns out is to much, turn in to lightly seated and turn back out 1 3/4 or 2 max.

Is the needle shimmed? ( if so use only one washer) is the slide drilled?

Bowl drain appears to be ok and clear. 4 turns was actually 4 half turns, so only 2 full turns. There were two washers on the needle, so removed one. Needle clip was about halfway on the notches. Don't see any difference between having a washer/spacer under the clip or simply lowering/raising the clip itself. Also checked the choke and fuel supply. Lowered the float just slightly, but waiting to reassemble re: valves...

Just tried to remove the cam collars in an effort to adjust the valve clearances (change shims) and could not budge them. May have to go dealer on this, god forbid. Can't imagine that is specs are 004-008 intake and 006-010 exhaust, that being at 005/008 in and 008/008 exhaust would really make much difference. These clearances are in-spec, but the KLR guys say to set at max clearances of 008/010. Go figure. Could a Japanese big single capable of crossing continents really be that sensitive?

...Needle clip was about halfway on the notches. Don't see any difference between having a washer/spacer under the clip or simply lowering/raising the clip itself.....

The whole deal regarding the washer under the clip is fine tuning. It allows you to go "1/2 of a clip" or inbetween clip positions.

Just pushed the bike home about 1/2 mile uphill. Note to self: next time test ride in an uphill direction and stop at the top, just in case.

Same problem exists, even worse after mods I did this time. I should also mention I live at 1,000' elevation and this bike has an internal-baffle Supertrapp exhaust. Elevation should richen it, exhaust should lean it out.

So, adjusted the valves and rechecked. Are now 007/008 intake, 010/010 exhaust. Perfect nearly I think. Got shims from BMW dealer ($4) after two Kawi dealers did not have in stock. BMW guy was a wiseass, but hey, he had 'em.

Checked the plug gap and is between 032-035, using a DPR8EA-9. Mine has no resistor on top, just the small pin and plug cap to match. Thinking I might try a hotter plug, so a DPR7EA-9. Does the R stand for resistor? If so, I have a DP8EA-9. Did not try the 7 yet.

Lowered the float as little as possible (slightest bend) to lower level of fuel in bowl. Pilot screw is out 1.75 turns. Tried raising the needle using one washer (1/2 notch). Vacuum tube to petcock is dry and seems tight and free of kinks. I removed the fuel filter and installed new 1/4" fuel hose. Makes no difference if I try to start with tank cap open or closed, so assume vent is fine. Choke plunger appears to be not hanging up and fully in when off.

The bike was harder to start cold this time. I assumed because bowl was dry and took some cranks to fill it. Backfired a few times before starting no-choke and then idling fine with choke. (tried choke on and off, open throttle no throttle, every combination I could think of. Even tried full throttle, gas off, an old Guzzi trick to clear flooding. Once running it had plenty of power. Was running it without air filter or air box cover as the K&N was drying after being cleaned with the official cleaner solution. Got to top of the big hill and it stalled. Bumped on the back side of hill in 1st and started, ran for a bit then stalled again when I dropped the revs. Tried to bump again and ran out of hill, would not start on starter. This brings me back to beginning of post, pushing bike uphill to get home. Bike did start when rolling fast down the home side, full bump in 1st, but had to rev it high to keep it running back to the garage.

I'm thinking to set the float back where it was and removing washer from under needle clip. Try a new plug (with NGK #7 heat range) and get a new coil, just in case. Running out of options so hope coil could be the culprit. Have not tried the following but will once the rain stops. Pull plug and test to see if the spark is bright. Try squirting starting fluid around the intake boot to see if there is a leak. Get a complete new carb. Go to a dealer. Wait an hour for the "rapture" to begin and quit worrying about motorcycles.

What do you think?

I set my valves closer to the tight side & re-check every 5,000 miles... you should be good there.

the pilot screw might be better at 3 turns out. (but it should still start)

does the engine spin normal during start or is it slow?

what does the compression release look like?

Find out what makes it start.... choke/no choke, throttle closed/cracked/open... what combination works.

EDIT: so you posted the above while I was writing....

If you are not positive about what is in the carb something I might try is going back to the stock needle & jet... the KLX needle is richer than stock & needs a smaller main jet. I was never happy with it & eventually went Dynajet KIT...I say kit because then you know what you have. Be careful when re-jetting because Kehin, Dynajet, and Mikuni use different sizes for the same jet number. Drove me nuts untill I figured out the parts guy was selling me Dynas & I was working with Kawi (Kehin) numbers.

was the doo done recently? I've seen a couple bikes where the key was knocked out of the rotor... eventually the rotor slips & this put the ignition timing off.... usually they will not run at all though.

Just pushed the bike home about 1/2 mile uphill. Note to self: next time test ride in an uphill direction and stop at the top, just in case.

Same problem exists, even worse after mods I did this time. I should also mention I live at 1,000' elevation and this bike has an internal-baffle Supertrapp exhaust. Elevation should richen it, exhaust should lean it out.

So, adjusted the valves and rechecked. Are now 007/008 intake, 010/010 exhaust. Perfect nearly I think. Got shims from BMW dealer ($4) after two Kawi dealers did not have in stock. BMW guy was a wiseass, but hey, he had 'em.

Checked the plug gap and is between 032-035, using a DPR8EA-9. Mine has no resistor on top, just the small pin and plug cap to match. Thinking I might try a hotter plug, so a DPR7EA-9. Does the R stand for resistor? If so, I have a DP8EA-9. Did not try the 7 yet.

Lowered the float as little as possible (slightest bend) to lower level of fuel in bowl. Pilot screw is out 1.75 turns. Tried raising the needle using one washer (1/2 notch). Vacuum tube to petcock is dry and seems tight and free of kinks. I removed the fuel filter and installed new 1/4" fuel hose. Makes no difference if I try to start with tank cap open or closed, so assume vent is fine. Choke plunger appears to be not hanging up and fully in when off.

The bike was harder to start cold this time. I assumed because bowl was dry and took some cranks to fill it. Backfired a few times before starting no-choke and then idling fine with choke. (tried choke on and off, open throttle no throttle, every combination I could think of. Even tried full throttle, gas off, an old Guzzi trick to clear flooding. Once running it had plenty of power. Was running it without air filter or air box cover as the K&N was drying after being cleaned with the official cleaner solution. Got to top of the big hill and it stalled. Bumped on the back side of hill in 1st and started, ran for a bit then stalled again when I dropped the revs. Tried to bump again and ran out of hill, would not start on starter. This brings me back to beginning of post, pushing bike uphill to get home. Bike did start when rolling fast down the home side, full bump in 1st, but had to rev it high to keep it running back to the garage.

I'm thinking to set the float back where it was and removing washer from under needle clip. Try a new plug (with NGK #7 heat range) and get a new coil, just in case. Running out of options so hope coil could be the culprit. Have not tried the following but will once the rain stops. Pull plug and test to see if the spark is bright. Try squirting starting fluid around the intake boot to see if there is a leak. Get a complete new carb. Go to a dealer. Wait an hour for the "rapture" to begin and quit worrying about motorcycles.

What do you think?

Check my previous post. I think it's called the "L mod". It totally cured the same issues you are describing.

I'm running a DG exhaust KLX needle with the clip in the middle position, stock pilot jet and a 142.5 main. Runs excellent. (after I did the whole canister removal thing)

Of course if you don't have the canister then I would check the vents. Next time it does this, open the gas cap to vent the system. Also you may have continuing issues with the Clutch and kickstand interlocks.

Go back to stock jettng/ clip position, and set/adjust as per the manual. Check for vac. leaks, and consistent fuel supply. You may want to bypass the clutch and kickstand saftey switches too.

Start with that, then adjust jetting to match elevation and any intake & exhuast mods.

Jesse

instead of the "L"... I drilled 4 one inch holes in the top of the box... easy to fix if you no like. I also pulled out the snorkle and the inner screen.

the original needle has only one position.... there are no grooves, only a pressed on/riveted washer on the top.

AND there is a little washer/spacer that has to be in there to hold the needle down... otherwise it has a bunch of extra movement before it contacts the slide. I don't remember if you need this on the KLX needle or not but I would check.

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