bike wont start

[stiz001]

Hi guy's my 2002 xr 650 has a problem.I changed the spark plug for the first time this morning and now the bike wont start.Will not kick over at all.There is plenty of fuel...no blockage .I tested the spark against the motor and could see a blue spark.Any ideas ?? my knowledge to bike mechanics so any advise appreciated....cheers

[Mark_Bear]

Can you expand on the won't kick over at all comment?

Does that mean the kickstarter wont go down?

Or is the kickstater turning the motor as over as normal, but it just wont fire up?

I'm assuming since you got spark at the plug it is turning the motor okay. I'd say if it was running before and not now it is probably just flooded, could try a few kicks with the throttle open wide.

Just have a look at the plug lead where it goes up under the tank, apparently older brp's can wear through the cable and short onto the frame, this may explain why it's only happened since you changed the plug, as in, you've move the cable. It would also explain why you get spark with the plug out as the cable would be moved away from the frame.

Other than that, checked the fuel tap, and does it have fuel...obvious I know but we all forget sometimes.

[stiz001]

Thankyou for the reply..I can kick thru the full stoke no problems.It just wont fire up..Will check the connection and the cap plug again...cheers

[stiz001]

i checked the cap looks ok..so do connections.One thing when i do kick it over it does not feel like the resistance im used to.The bike was running fine before i changed the damm plug .Same problem when i try the old one as well.

[frankstr]

You did gap the plug, Right...........

[asapenter]

sounds like the hot start is stuck open

[stiz001]

Yes i did cap the plug.Checked the carb tonight...Seemed fine cleaned out the jets.Tried kicking over still no good.After about 10 kicks there was a loud bang from the exhaust...Not sure why it did this???

[pbusanga]

sound to me like you do not have compression. check seal on plug to cylinder. check that cylinder head threads have not stripped out.

good luck

[Max Power]

Yes i did cap the plug.Checked the carb tonight...Seemed fine cleaned out the jets.Tried kicking over still no good.After about 10 kicks there was a loud bang from the exhaust...Not sure why it did this???

Well at least you know you got spark.

Choke on or off?

Why did you change the plug?

[stiz001]

Have tried starting with and without choke.I changed the plug as i had not since owning the bike and have put about 2500 miles on it.Plus the cap was dirty alot of brown residue so i thought it was time for a change.

[Max Power]

Have tried starting with and without choke.I changed the plug as i had not since owning the bike and have put about 2500 miles on it.Plus the cap was dirty alot of brown residue so i thought it was time for a change.

Hmmmm. The only time I get a backfire on my bike is when it is flooded. Have you tried to go down a hill and jump start it?

Maybe put the old plug back in.

Has the bike been sitting for a while? Bad gas.

Make sure you haven't pinched the de compression cable(make sure there is play in the cable/lever).

[TREADMARKS]

If it has fuel,

And if it has air,

And it has a spark,

It will run.

Make sure the fuel is making it to the cylinder.

Make sure the air is making it to the cylinder. (Take the plug out and make sure there is air trying to get out of the empty plug hole on the compression stroke.)

Verify it has spark by connecting the removed spark plug cable to the spark top and holding the spark plug base to a secure grounded item, like a frame bolt or cylinder head fin without paint.

The rest is up to you my friend.

[Mark_Bear]

Is the handlebar decompresser working okay, obviously if it's stuck you will have no compression and it won't start. Check it's movement and free play. It's unlikely tho since all you did was change the plug.

Lika a previous post, to start you need;

1. Spark

2. Fuel/air in the right mix

3. Compression

It sounds like you are missing compression.....

Is there anyone near you who can have a look?

[Max Power]

It's unlikely tho since all you did was change the plug.

True. For some reason I thought he pulled the tank. My bad.

It's a Honda. It should practically start on its own.

[captb]

Operate the decompressor lever and watch the arm just above the spark plug, you may have mucked it up since it's close to the spark plug, make sure the arm isn't bent or jammed and the cable should have feeplay, it won't start decompessed and it sounds like that's what it is, if you had the tank off you may have the cable routed wrong, good luck.

[stiz001]

Thankyou for all your advise ..It is booked into the shop for friday so hopefully they will sort it out.My mechanical knowledge is not that good so i best leave it to the experts.One question ..is it normal when you kick the bike over that air should rush out the breather hose tube as you kick thru the stroke??...Many thanks

[Max Power]

Thankyou for all your advise ..It is booked into the shop for friday so hopefully they will sort it out.My mechanical knowledge is not that good so i best leave it to the experts.One question ..is it normal when you kick the bike over that air should rush out the breather hose tube as you kick thru the stroke??...Many thanks

Breather hose tube.... you got me there. The only breather tube that I know of is the one from the crank case to the air filter box.

Let us know what you find.

[stiz001]

Well just have been advised the bike has ZERO compression...Pulling it apart today will advise what goes...cheers

[stiz001]

Well just have been advised the bike has ZERO compression...Pulling it apart today will advise what goes...cheers

[TimBrp]

Bummer, good luck!