cr 125 wont kick over

[whaley]

i have a 1998 cr 125 and i just put a new top end in it after the other one blew up(the piston and head had a bunch of dents on it) and i put it all together and kicked it and it started right up but it idled to high so i shut it off i did that two more times and then went to kick it again and it wouldnt kick at all. i pulled the head and cylinder and the piston is fine but the crank wont turn can you tell me what might be wrong or what i have to do, or should i take the motor to a shop and have them diagnose it, does anyone know how much that would cost to just diagnose it?

 

[2-strokes-4-life]

sounds like the lower crank bearing seized on you.if so,the cases will have to be split and the crank either rebuilt or replaced.

 

[TimberPig]

i have a 1998 cr 125 and i just put a new top end in it after the other one blew up(the piston and head had a bunch of dents on it) and i put it all together and kicked it and it started right up but it idled to high so i shut it off i did that two more times and then went to kick it again and it wouldnt kick at all. i pulled the head and cylinder and the piston is fine but the crank wont turn can you tell me what might be wrong or what i have to do, or should i take the motor to a shop and have them diagnose it, does anyone know how much that would cost to just diagnose it?

So in simple terms, it threw a rod, took out the top end, you didn't determine why the top end went down and just through a new top end in, and then the lower road bearing seized up solid.

As already said, your lower rod bearing let loose, throwing pieces of rod bearing up through the transfers, which produced the pits you see in the piston and head. That right there should have told you there was more wrong than the piston and rings alone, but you missed it or ignored it and the result you know now. Engines very rarely simply seize up of their own free will, there is almost always some deeper seated underlying cause of it, that needs to be determined first in order for the repair to last. Simply throwing parts at it without determining the cause normally ends up costing more in the long run, because the new parts are most often destroyed when the cause of the failure is not corrected first. In this case, you got lucky and the only additional cost is a cylinder base gasket, beyond what it would ahev been to correctly fix it in the first place.

You need to tear the engine down completely and split the case. The crank needs to be rebuilt or replaced, and a fresh set of main bearings and crank seals installed, in addition to the gasket set for the rest of the engine. If you aren't confident in your abilities, then you can still save some money by removing the engine and installing it yourselfi. Don't bother tearing the engine down too much, as the teardown of an engine removed from the frame isn't very costly, and many shops charge extra to reassemble basket case engine brought to them in parts, often more than if they tore the engine down themselves in the first place.

 

[whaley]

so should i just take the engine out of the bike and keep it all together and take it in. do you have any idea what it would cost to fix it.

 

[titoislaidlow]

Depending on the severity of the problem. For the seals and new bottom and top end parts expect around $500 or more. If you can save any of the new parts you just bought you can cut the cost.