Motorcycle Repair: Bike wont start, kawasaki kmx 125, overflow pipe

Question
Hi Chris
Thanks for your speedy reply, it was very helpful. We replaced and checked the spark plug, and it is continually oiling up, with no sign of petrol. Cleaned the carb completely, checked the float chamber, everything seems fine. I found a rubber pipe(possibly quite important) attached to the underneath of the silencer, it leads back through the frame to somewhere near the engine, but I have no idea where it attaches to. It has definately been connected somewhere as the pipe end is clean, do you suppose this is important! And could you tell me where it connects? Again, many thanks, and a Happy New Year.
Val
 
Followup To
Question -
We have a Kawasaki KMX 125 bike which has had the indicators, lights and battery removed. We used the bike a couple of times with no problems, then it started to need bumping off to get it going as when we tried kick starting it it just wasn't working. Now the bike won't even start when we try to bump it off, there is a spark, it backfires every now and again. The air filter is clear, sometimes when we are trying to start it the petrol comes out of the lower overflow pipe on the carburetta. There is no distinct smell of petrol coming from the exhaust when we try to turn it over.  Please could you email me your answer if you have any idea's, thanks a lot.

Answer -
Hi.
 Have you pulled the plug to see if the cylinder is flooded?  If it is, then it will not start until that is no longer saturated.

How about cleaning the carbeurator?  it ssems that the float may be sticking, which could also cause flooding.

Check the spark plug.  Is it in good condition and gapped properly.  Remember that just seeing a spark is not a guarantee of proper operation.

Have you checked the compression?  It is possible that something is bad there as well, but that is the least likely.

Start with that and let me know what you find.

Good luck and ride safe.
FALCON

Answer
Hi Val.
 That tube must connect to something, but I have no idea what it would connect to.  The repair manual should show you where it connects.  If you haven't gotten it, do so.

As far as the oil-fouled plug, there is obviously a problem with the fuel flow that needs to be addressed.  Perhaps it is in the pre-mix.  There should be a troubleshooting guide in the manual that will address those things.

I am sorry that I couldn't help more, but my experience with 2-strokes is rather more limited than my experience with 4-strokes.

Good luck and ride safe.
FALCON