Main Forum - Main crankshaft seal?

Hi and welcome to the forum.
As you may have seen already, most of the forum users are Dutch and write in their native language. We are most willing to switch to English if there are English users on the forum.

But referring to youre question, it's not completely clear to me what you mean with the seal between the rotor and stator. I presume you mean the left crankcase seal.

I never had any problems with leaking seals my self, but if the seal leaks the engine will run very poor. During the scavenging stroke the engine will lose crankcase compression, this will result in poor scavenging.

The best thing to do is to revise the engine. By revising the engine you can be sure that all seals are working properly. Also you can replace the two main crankshaft bearings. These two bearings wear very quickly.

Of course you will need special products fore the revision that will be hard to get in the usa. Especially gaskets will be a problem I think.
Maybe we could sent you some parts with the mail, but I don't know how much the postal rates are.

In the Netherlands there are still many parts available for the mb5, so if you really need stuff we may arrange something.
You said you are racing the bikes, usually this will means a lot of wear on the piston, rings and cylinder. In the Netherlands there are still a lot of fast cylinders for sale.

Greetings

 

Yeah 50cc Super Screamers sounds realy kick ass!!!!
do you have some pictures of your MB?

I've had a leaking crankshaft seal to on my Honda MT5 (I don't know i've they're also known in the USA, the engine is the same as a MB-5 engine)
Replacing al left seal is easely done in a few minutes, for replacing the right seal, you have to split the entire engine... :(

Checking if your seals are leaking or something like that is easy: Poor a cup of feul in de crank-case, untill itd full, wait a few minutes, and if the feul-level in the crank case lowers, one of your seals is leak (or both...)

Leaking seals cause the bike loosing presure in the crank-case, that make's your bike run bad, or it wil not even run at all...