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TTR125 knocking HELP!

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okay today i got a 107.5 main jet for my ttr125 and i opened the airbox up a little not a lot because i didnt get that much bigger of a jet. i put it all back together and started it and it ran fine and i rode it around my house for a few minutes. i started it a little bit later and now its knocking! i thought maybe it had something to do with changing the jetting so i put the stock jet back in and its still doing it. does anyone have any ideas? my step dad thinks maybe the wrist pin bearing went bad but he doesnt know. its a 2001 and has never had a new top end so do you think this could be it?

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okay today i got a 107.5 main jet for my ttr125 and i opened the airbox up a little not a lot because i didnt get that much bigger of a jet. i put it all back together and started it and it ran fine and i rode it around my house for a few minutes. i started it a little bit later and now its knocking! i thought maybe it had something to do with changing the jetting so i put the stock jet back in and its still doing it. does anyone have any ideas? my step dad thinks maybe the wrist pin bearing went bad but he doesnt know. its a 2001 and has never had a new top end so do you think this could be it?

OK, bear with me-Does it have oil in it?:thumbsup:

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valve hitting the valve cover.

My xr80 has done it for years but its my beater bike so why fix it.

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If it is too lean then it will ping under acceleration. However, it sounds like you have a connecting rod knock. If so, temperature and jetting won’t make a difference. Also, if it is a rod knock then it will increase in frequency as rpm’s go up (i.e. revving it some in neutral). If you think that is the situation and the compression is still good on the motor than you should take it apart and change bearings, inspects the piston, replace rings and the like. Otherwise, you have a time bomb and further riding will cause significant damage to the internal components and may kick the rod out of the block.

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Perhaps it was due to the oil change. Try to use a good synthetic motorcycle oil or Rotella Synthetic 5w-40 from walmart. Perhaps you are using the wrong oil.

Im guessing the knock isnt that loud and it is just pinging alittle bit from thin car oil.

Worth a shot?

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It started knocking before i changed the oil. And the oil that was in it when it started knocking i've had in there for around 2 months now. But i did take the motor apart and the piston looks completely fine, and so far the valves look fine. but there is a small burn mark on the crank and im leaning towards it being the rod bearing. it moves back and forth slightly but i think that is normal but i still dont know if thats the problem or not. i hope its not the rod thats going to cost alot to get fixed!

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I don't know what year you have but after looking at the mirco fishe on the '07, I would offer the following comments:

It will have some left to right movement on the crankshaft pin between the two halves of the crank assembly. It should have no looseness in the wrist pin of the piston or main rod bearing in the up and down stroke movement of the piston and connecting rod assembly.The crankshaft pin is fairly inexpensive ($16.68) so if there is any visable signs of damage (flat spots, pits, galled areas, etc... then you should replace it.

Would also recommend you replace the main rod cage bearing ($22.18) if there is any visable wear on the needle bearings in the cage. Does the skirt of the piston look fine? Sometimes on a worn motor you can get piston slap against the cyclinder walls and it would be visable on the lower skirt of the piston.

Lastly, if the wrist pin and journel surface on the small end of the connecting rod looks fine then you should be in good shape to reassemble. Since it is apart, you should check you ring gap and put a new set of rings in it. Let us know how it goes.

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I don't know what year you have but after looking at the mirco fishe on the '07, I would offer the following comments:

It will have some left to right movement on the crankshaft pin between the two halves of the crank assembly. It should have no looseness in the wrist pin of the piston or main rod bearing in the up and down stroke movement of the piston and connecting rod assembly.The crankshaft pin is fairly inexpensive ($16.68) so if there is any visable signs of damage (flat spots, pits, galled areas, etc... then you should replace it.

Would also recommend you replace the main rod cage bearing ($22.18) if there is any visable wear on the needle bearings in the cage. Does the skirt of the piston look fine? Sometimes on a worn motor you can get piston slap against the cyclinder walls and it would be visable on the lower skirt of the piston.

Lastly, if the wrist pin and journel surface on the small end of the connecting rod looks fine then you should be in good shape to reassemble. Since it is apart, you should check you ring gap and put a new set of rings in it. Let us know how it goes.

Let me add to that list a set of crank bearings (you're already there) and a complete gasket & seal set (never reuse gaskets).

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I am 90% sure that the primary drive gear is causing the knocking. i read around and some people say that the clutch basket will wear out and move back and forth a little bit from the gear, and thats what mine does. i took the clutch off and left just the basket on and started it and it still makes the knocking noise but not as loud, so im pretty sure this is whats wrong with it.

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