Hi all,
im having big problems getting my 2004 TE 450 to start,the engine turns over well but fails to start,bike was running the day before during a muddy event well then got back washed her down & started up after cleaning without a problem then next day hit the start button & just cranking over but no life ???

Checks so far:
Good spark, clean air filter,valve clearances in tolerance, crank timing ok,flywheel woodruff key in place for spark timing(flywhell not removed but can see key in place), pilot & main jet clear,all electrical connections cleaned up ......not yet done a compression test,......if you hook up to a car battery & let it crank long enough it will sometimes come to life & tick over without any problems but hit the kill switch then try start again then just ages of cranking without life,I suspect fuel starvation on start up but carb seems clear,is there anything else I should be checking with the carb or anywhere else on the bike ??

Any advice appreciated.

I'm just making a wild guess, but how about auto decompression failing?

check for water in the air filter or fuel.

Is the fuel fresh?

Ahhh, just set it on fire!

try your normal start routine a few times then pull the plug and see if it is wet or dry? check for strong spark while you got the plug out. If it's getting spark and fuel it should run, unless the intake valves are tight off their seats and it's not making compression.

Also, using the kickstart does the bike feel like it's kicking over normal, or do you feel and hear some weird drag? We had a battle with this same bike where the starter clutch wasn't disengaging. never could get the thing to start till we pulled the starter out of it. Rode the rest of the day with the hole plugged.

Make sure your carb float needle isn't stuck open and flooding the motor with gas.

My car did that to me once (Holley 4150). A sharp tap on the needle top takes care of the problem on the car (I do it if the car's sat for a long time). The bike might require the carb to be taken apart and cleaned thoroughly. My friend's DRZ400 clogged the pilot jet after sitting for awhile (crappy CA gas). We needed to replace the thing.

After cranking for a bit, if the plug is wet, I bet that's your problem.

If the gas was contaminated, it's more likely to stick a float needle too.

-Dave

Thanks for your replys,the plug is wet but not soaking after cranking over but the concern is that even if you drop a little WD40 or fresh petrol down the plug hole then try to start theres not even an attempt to start just cranking,will do a compression test later & post the readings.

Had a similar problem on a Honda years ago. Was getting air, fuel, and spark, but wouldn't start. Traced it down to a bad rectifier. Also, jumpstarting from a car is a sure way to overload your bikes electrical system. You cannot put 600+ amps through a system designed to run on 10 amps. It will fry wires. Check for blown fuses. I don't know the exact amperage of your bike so putting 600 amps of current through a 10 amp system is just an estimate. Many people think that the 12 volt battery in their car is the same as the 12 volt battery in their bike, but not true. First of all you see a physical size difference and that size difference is to get more amps (electrical current) out of the battery. Usually, the size of the battery correlates to the amperage of the battery. Of course there are always exceptions to that rule. Try this: Take the battery out of your bike and try to start your car with it. You probably don't have enought amperage in the bike battery to make the car solenoid click. Hope this long winded response helps.

I had this problem with my 250 same year. Dont bother with a compression test.

I know this sounds weird but try bumping it. The spragg clutch went on mine and it really did sound like it was turning over fine but must of been slipping at the vital part of the stroke.

Also dont bother kicking it,that is also a waste of time.

Just in case you guys call it something different, bumping is getting your mate to push you down the road and chuck it in 2nd.

Have done a compression test as had tester to hand,with engine cranking at a good pace with throttle wide open was getting what I think is a poor 80 psi,did drop a little into the bore & re tested & was getting approx 140psi so going to take the head off & check it all over as was planning to check it all soon anyway.

135-140psi is all you will get with an ADC working, the ADC bleeds off compression so that you can start the bike.

Check your intake manifold boot. I was riding the bike on the trails, all was running fine, and I killed the bike on an uphill, tried to estart it, ran the battery down, tried to kick it, couple hundred times, reached down and felt the intake loose, taped it up with black tape and rode it out. And this is on a 2010 TE450.

did you check for a good spark when you had the plug out?

Porkyblader, on 06 February 2012 - 02:37 PM, said:

I thought you squirted oil in the hole and got 140........80 is a problem, if you really got 80 before the oil squirt, and 140 after the oil squirt, you may have a ring problem, maybe a ring is rusted/stuck in the groove....

or intake valves off the seat tight, checked their clearance?

briggs1, on 06 February 2012 - 08:58 AM, said:

The current will not be 'forced' through the system. The circuit draws as much current as it needs, depending on the load. True, a larger battery can supply more current, but that doesn't mean the circuit will draw more current.

andicus, on 06 February 2012 - 08:18 PM, said:

Correct, I've jumped several different bikes off a truck battery, including my Husky, all with no damage.

briggs1, on 06 February 2012 - 08:58 AM, said:

as mentioned above. The battery will not force amperage into your electrical system. The car battery has the capability of providing more amps for a longer period of time than your motorcycle battery. With no load on the system the battery does not provide any amperage. If the starter draws 10 to 20 amps, that is all the battery will produce. Your motorcycle battery can power your car just fine once it is started. The load rating is primarily for starting.

Sometimes, if the starter load causes the battery voltage to drop to low, the ignition system will not have enough voltage to fire the coil. The car battery does not drop with the starter load so the ignition keeps firing. I had this problem once on a different brand of bike. I would crank the bike and it wouldnt start but sometimes it would start when I let off the start button and the brief moment of freewheel with full voltage to the ignition, the bike came to life. A new battery cured that one.

All that being said, it is possible you got some water in the fuel bowl through a vent tube or something. Shut off your fuel and drain your carburetor. Re open it and let fresh fuel run to the bowl. It is cheep and easy to try.