Vintage Dirt Bike Q & A

Hey guys I am having trouble with my Mt250. I swapped engines on it and now I cannot get it started. I have spark, I have 155psi of compression. If I put fuel in the cylinder and kick it over, it still will not start. Do you guys have any ideas? I am at a loss, I know my bike pretty well, but its kicking my backside.

Please Help
Jordan

Make sure the points are good and making a strong spark and make sure the timing is good its real easy to set.

The points are new and set correctly I am going to have to take another look at the timing. Thanks

Jordan

Well I think that my riding season may be over before it has even started.

I just got back from the garage where I set the timing, adjusted the points and made sure that I had sufficient spark.

After a few starting attempts and still nothing, I tried to use some carb cleaner hoping to get it to at least pop. Still nothing

So I got off and pulled of the magneto and got it to look like this.




After I got the magneto off I realized that there was smoke coming out around the crankshaft. So my thoughts are bad crank seal.

Is this the right conclusion, and can this be causing my problem? If this is the case I am pretty f***ed because that would mean that both of my engines need the cases split, and right now I do not have the money for that.

Let me know what you think guys. Did I come to the right conclusion?

Jordan