Eton Beamer Air leaks-Hydrolocked?

[mrp7744]

I moved this thread from 50cc and up section...

I have a 2001 50cc Eton Beamer.

Hasn't run in years-was running a 70cc kit but I'm going back to stock because I could never get the upgrade to be dependable

Just installed a new piston and cylinder(50cc) and the piston is in the right way.

The carb is clean-The fuel petcock seems to be good

It wants to start if you hold your hand over the intake but just before it does it locks up or seems to sieze. It will also backfire through the pipe. (Its like the timing is off if it were a car)

I turned the bike upside down to empty the crankcase of any residual oil in case that was the problem and have pulled the carb apart 20 times and tried 2 float needles.

Reed valves seem fine-engine gaskets are new- bike has 145 pounds of compression and good spark etc. What am I missing??
Please help! Thanks

I'm in the process of replacing the crank seals as another member suggested but I'm not sure they could leak enough air to make the bike not run. We'll see.

[naseqp]

If you're getting a true backfire through the carb you probably do have a reed sealing problem. They have to seat when the engine fires....if...and thats a big iF its firing when it supposed to.

When it "locks up" how are you freeing it up?

[naseqp]

sorry reread your post on backfire, coming through the exhaust pipe is firing before pistoncovers the exhaust port.Is this an eTon cyl/piston or?
On an engine a leakdown test (piston at top dead center) will tell you if the basis engine is "tight"

[mrp7744]

Thanks for the replies. It backfires through the pipe. I think I have a genuine eton piston/cylinder. Got on ebay and it looks the same as the originals.

When it locks up I can either take the plug out and turn it over a few times or wait awhile and then it will crank easily again.

Just got new crank seals from anything atv (took almost 2 weeks) so I will see if that helps.

BTW I got a new stator from the dealer because it had no spark. It has spark now but I did have to rewire the stator as the plug was slightly different. The stator itself seemed the same. Could it be wired wrong causing a timing issue? I matched up the wires by color/pattern.

[naseqp]

A seal leak on a two stroke will draw air as it runs, causing a leaner and leaner fuel air mix (which raises rpm) until it gets more air than it can run on and the engine dies. Locking it up....not likely.

A "stator" is part of your charge system. If you mean cdi or ignition module, revsist for correct p/n.
For an engine to seize, causes are a few and not good. At this point I would pull the engine down and check for "scuffing" on the piston/cylinder. Also, if this is an oil injected engine (most etons are) have you verified oil pump is working.....or just premix to be sure.
Good luck.

[naseqp]

or if something in the drive is causing the sticking, pull off the belt and see if engine runs with no problem.