Are rod kits difficult to install on modern 2 strokes (Beta 125)?   The only one I have installed was on a BSA C15.  It was very old and rusty.  My cheap 30 ton press groaned pushing it apart but got the job done.  Any recommendations?       

Unless you have very good skills to balance the crank, I would let a pro do it.  Your 125 spins a bunch more RPM compared to the BSA.  I'm not saying you don't have the skills.

 The newer bikes have plastic inserts instead of a full crank. Which makes it difficult with out the right set up.

lineaway - Can you elaborate?  It there nothing square to the pin to push on?  I have not split the cases yet but do see quite a bit of plastic on the crank.

Well if you are looking at it, you should be able to tell if you are tooled up enough to do it. The last time I looked at one I passed as I did not want to screw with someone elses crank. If it was mine, I might of tried. I have done a few dozen over the years, but all solid cranks.

Your bike (and all modern Beta 2-strokes) with the plastic inserts have full circle crankshaft flywheels.

The plastic bits on each crank flywheel are there to increase the crankcase compression ratio.

Be very careful with them, as they are not available separately and if you damage one you will have to buy a new crankshaft.

That said, there is nothing different in the procedure for rebuilding your crankshaft than any other 2-stroke crankshaft around today.

I see what you mean.  Do you know what the proper tooling looks like?   I have seen pictures of 1/4" angled steel to go through the center as a base for pressing.  With that, it looks like I could make a split ring/ spacer to sit on the flat area around the rod.  This spacer could support from angle to crank wheel.  1/4" does not sound like much but there is only about 9 mm between the wheels. 

So it is the price of a rod verses the crank price. If it was mine it would be done already.

I have to laugh as the first time I saw one I declined the work. The rod was good, but the guy insisted on a new rod.?

Someone suggested I could use a chop saw to cut the big end pin to get it apart.  Once the rod is off, it should not be difficult to support and press out what is left of the pin.  Looking ahead, what happens if I press the crank too tightly together.  Is there a way to correct or would I be back to the same problem but now have a big paperweight?  It is for a friends bike and I'm not finding a local shop that does these.

Well what Mexican recomended a chop saw? You are out if your league.  Send it to a compentent shop.

It seems to be the accepted method for Honda tin can cranks.

 

 

 

 

A hot saw blade vs the plastic insert. The question is will the inserts come off without damaging them? Update, I forgot the insert is actually held in place by screws.

Edited April 15, 20197 yr by lineaway