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Cylinder Is Off And The Piston Is Free! Whats Next?


trialsnewby
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So it came out like you all said, WD-40, a mallet and a little patience. I have to be honest, the barrel and piston look to be in GREAT shape. . . i think. Ive added a couple pics of the piston and i'll do the same when I clean out the barrel. How's it look to you guys??

So whats next? I wasnt able to get the crank shaft moving?? Could the bottom end be siezed also? How can I check? If I can get the crank to move up and down, im going to be REAL excited! So any advice on where to go next? How can I get the crank to move? Turn the wheel? Kick start wouldn't move it. . .

Piston pics, any thoughts?

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Im going to shop for new rings, piston and all that Jazz pretty soon, but i'd really like to make sure the crank is going to turn!

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have you tried to turn it with the flywheel, it should move with ease,its starting to look a little more serious but its not that hard to split the engine if the bearings have had it.

Im not exactly sure how to get at the flywheel yet?? Im in the procces of getting the manual from arun1664, but untill then, im pretty much stuck.

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Well, if I had to take a guess by the photos,

The piston looks pretty good, and the rust in the cylender mostly superficial, nothind that a good cleanup would not suffice!

Problem seems to be your crank bearings are siezed, if it will not turn.

This is a bad indication, and even if you get it to break loose by soaking, and turning, the bearings will be damaged and will totally fail shortly thereafter.

Wish I had better thoughts for you, but looks like a complete split of the cases is in order. :thumbup:

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Well, if I had to take a guess by the photos,

The piston looks pretty good, and the rust in the cylender mostly superficial, nothind that a good cleanup would not suffice!

Problem seems to be your crank bearings are siezed, if it will not turn.

This is a bad indication, and even if you get it to break loose by soaking, and turning, the bearings will be damaged and will totally fail shortly thereafter.

Wish I had better thoughts for you, but looks like a complete split of the cases is in order. :thumbup:

That seems to be what im hearing from most. But, it was suggested to me that if its only a "minor" sieze, meaning the the rust has just settled into the bearings, it may turn out alright. A local guy mentioned to me that since the rust was SO minor on the barrel and piston, it was more likely than not that the same amount/type of rust is probably holding the bearings tight also. So if I were to get it loosened, then soak it in a thicker oil, then drain it and SLOWLY keep working the bearings, it would probably be alright for use. He mentioned that even though it was sitting a while, the rust may have only recently seeped through the seals and caused the sieze.

Does that sound logical to anyone here? Or was that just a load of crap??

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Well, if I had to take a guess by the photos,

The piston looks pretty good, and the rust in the cylender mostly superficial, nothind that a good cleanup would not suffice!

Problem seems to be your crank bearings are siezed, if it will not turn.

This is a bad indication, and even if you get it to break loose by soaking, and turning, the bearings will be damaged and will totally fail shortly thereafter.

Wish I had better thoughts for you, but looks like a complete split of the cases is in order. :thumbup:

I'm with my learned friend from Texas ( well copey anyway...don't know about learned :D ) on this.

Don't be fooled by superficial rust, if you want your hard work to bear fruit then replace the mains, seals, get the big end checked, the whole lot. Same goes for the gearbox and clutch, get them checked and replaced if needed. There's no point in you doing half a job with a restoration, got to go the whole way. Split the engine do it properly mate.

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Does that sound logical to anyone here? Or was that just a load of crap??

No

Yes

If the main bearings or big end bearing has suffered any corrosion at all, they will self-destruct soon after you start the motor the first time, sending metal particles everywhere, meaning that you will need to rebore the barrel yet again. It is the bearing surfaces that usually rust - the balls and rollers etc, it doesn't creep in from elsewhere.

By the look of the piston pin, I would say that there has probably been corrosion happening within the crankcase. When you work out why the crank will not turn, you will be in a better position to know what needs fixing. The bottom end may not be siezed via corrosion in the bearings. It could have something jammed in the meshing region of the primary gears. I have seen that in a TY175 motor with a loose piece of clutch casing floating around until it jammed up the primary gears, bending the gearbox shaft and wrecking the primary gears in the process. Until you can see what is really happening, it is all just conjecture.

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So here's the barrell from my siezed 76' Yamaha. There are NO gouges what-so-ever. Totaly smooth. Those dark spots are just spots that I missed while cleaning it. Thier smooth, just dark. Does it look usable to you?? Should I still have it honed?

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Tip some oil and wd-40 down into the bottom end and leave it soak for a couple of days, then knock it into top gear and rock the bike back and forward in gear and it should free the bottom end!! then you'll be able to turn the crank and listen for strange noises or tight spots in the rotation!?!?

If it sounds dry or tight strip it and change the bearings.

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The barrel and piston look very good to me, much better than most and the I75 is prone to piston and barrel gouging! I would fill the lower portion up with any good oil to at least cover ALL of the crankcase bearings an ATF oil is good at penetrating most bearings. Leave it for a couple of days (patience) then drain off and proceed as per previous instructions. I would personally use the top half as is but do clean the rings. If you get it freed off, as seems likely, then you can check the bearings by seeing if there is any "lift" on the shaft, do this by lifting the flywheel. With the ammount of rust you will need to replace the points and condenser so get a TY175 flywheel puller (the 250 will not work). I suspect the stator plate will be a mess along with the inside of the flywheel.

Tony

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The barrel and piston look very good to me, much better than most and the I75 is prone to piston and barrel gouging! I would fill the lower portion up with any good oil to at least cover ALL of the crankcase bearings an ATF oil is good at penetrating most bearings. Leave it for a couple of days (patience) then drain off and proceed as per previous instructions. I would personally use the top half as is but do clean the rings. If you get it freed off, as seems likely, then you can check the bearings by seeing if there is any "lift" on the shaft, do this by lifting the flywheel. With the ammount of rust you will need to replace the points and condenser so get a TY175 flywheel puller (the 250 will not work). I suspect the stator plate will be a mess along with the inside of the flywheel.

Tony

So I just have a quick question. Im filling the crank case with oil. Is there a drain for the crankcase?? Or will I need to remove the engine and flip it over?? I sure hope there is a drain hole. . . :thumbup:

Edited by trialsnewby
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Theres no crankcase drain on a TY175. Turn the whole bike over and catch it in a pan. If youve taken the handlebars off it might be easier to remove the primary gear and the spacer behind and tip the bike on its right hand side. Don't take the motor out of the frame till you have loosened all the shaft nuts and engine inner casing screws as it is a good way to hold the motor still.

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Theres no crankcase drain on a TY175. Turn the whole bike over and catch it in a pan. If youve taken the handlebars off it might be easier to remove the primary gear and the spacer behind and tip the bike on its right hand side. Don't take the motor out of the frame till you have loosened all the shaft nuts and engine inner casing screws as it is a good way to hold the motor still.

Do you think if I just removed the front wheel, I could tip it forward, kinda like an endo?? Would that work? Just let the oil flow out of the front of the motor?

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Do you think if I just removed the front wheel, I could tip it forward, kinda like an endo?? Would that work? Just let the oil flow out of the front of the motor?

You just have to turn things upside down, like bars and rear support tripod!

Agree the top looks very usable!

You see, if the bottom roller balls have siezed due to water, this will certainly pit and score them. After that, it is just a matter of time usually, as they will beat themselves to death on the pitting like a cobbstone! The time only depends upon the severity and the stress imposed thereafter! And it varies. :thumbup:

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