83 kx 125 restoration & first start-up problem

[thunderkiller]

Hi to Everybody,

I am a new user friends. I live in Turkey. I have a V-strom DL 1000 as my primary bike.

4 months ago I bought a very old dirtbike like a toy to learn about 2-stroke dirtbikes having 83 rm 125 chasis & 83 kx 125 engine. I am trying to re-built it.

The chasis is ok now, all bearing, swingarm, suspension etc. renewed and in great condition now.

About the engine; I have renewed all the bearing at bottom end and rebuilt the top-end with wiseco piston&rings & LA sleeve.

During my internet surfing I found this great site.

Now my question; After rebuilt the top-end, I tried to start the engine but couldn't be succesful until I put some fuel from spark hole. After that it burned the fuel 2-3 seconds and stopped. I again tried to put some more fuel from the intake manifold and tried again then it burned the fuel again for 5 seconds. But newer works again after my 40-50 start-kick in two days. This time I tried to create more pressure diff. by closing the carburetor air filter side by my hand (manually choked it) and it again works for 5 seconds and stopped again. I think I have a carb problem although I cleaned it
-I have a good spark ark that can be seen with eyes.
-I didn't measured the compression but I'm sure that it's good although it is a complete new top-end and it burns the fuel if a put the fuel manually.
-reed valves seems in good condition, no space I can observe, they completely close.
-Carburetor fills with fuel in correct level.
-the exhaust pipe and air filter not connected yet because the engine mountings needs to be alligned why the chasis and engine are different brand. I cleaned the carburetor before trying to run the engine.

what could be the possible reasons and your recommendations to check about this issue.

thanks in advance

 

[julien_d]

Have you replaced the pilot jet? That's the first thing I would think of being that it fires up if you pour fuel into the cylinder.

--the exhaust pipe and air filter not connected yet because the engine mountings needs to be alligned why the chasis and engine are different brand. I cleaned the carburetor before trying to run the engine.

Do not start the engine without a pipe attached. This could cause you some very major problems.

J.

 

[thunderkiller]

another issue that i want to add, the hole on the carburetor where the throttle cable enters do not have any seal or something like that, does it effect something wrong like decreasing the pressure drop between inlet & outlet of the carb.

Have you replaced the pilot jet? That's the first thing I would think of being that it fires up if you pour fuel into the cylinder.

--the exhaust pipe and air filter not connected yet because the engine mountings needs to be alligned why the chasis and engine are different brand. I cleaned the carburetor before trying to run the engine.

Do not start the engine without a pipe attached. This could cause you some very major problems.

J.

yes, i have dismounted the pilot jet and cleaned it well.

for the pipe, can it be a problem for just to start engine on try in low rpm for 30 seconds.