Seal on bottom middle?

Oh and I found another spot where they smeared some thing on ( could only see after cleaned)
 

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So I got it apart. You couldn't pay me to put those Philips head bolts back in will definitely be ordering new ones.

A IMPACT SCREW DRIVER IS A MUST had to go get one

Anyways I worked the case apart just with my hands. And everything was looking good then... I FOUND THE CRACK lol

Bummer

Now what?


Oh and that piece of metal feel out when I was flipping the motor over?

And what years could I pull one from?
 

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That's funny I just ordered that

I also got
- new case side
- carb rebuild kit
- crankshaft puller/ clutch holder
- wise I bottom end kit

Going to take top to shop sometime this week and see what they say

Am I missing any thing?
 
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so i measured the cylinder

top 66.77
middle 66.84
bottom 66.73 averages

so i should be able to get a 1.00 over bore piston right?
 
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Your average (if you measured correctly) then becomes 66.756.
So...the next jump is 1/4 mm, or .025 mm (depending on piston manufacturer).
.025mm = .010 inch, or ten thousandths of an inch.
Depending on the "out of round" of the bore, I personally, ....would safely say ... that a 67.00 mm piston of your choice would clean up the bore after machining.
That's a .005 (5 thousands of an inch) "Swipe" all around the bore. This will be enough to straiten and make the bore round again. This is dependent upon any deep gouges or grooves you may have, that need to be removed.
I only seen one photo, which wasn't enough.
 
Your average (if you measured correctly) then becomes 66.756.
So...the next jump is 1/4 mm, or .025 mm (depending on piston manufacturer).
.025mm = .010 inch, or ten thousandths of an inch.
Depending on the "out of round" of the bore, I personally, ....would safely say ... that a 67.00 mm piston of your choice would clean up the bore after machining.
That's a .005 (5 thousands of an inch) "Swipe" all around the bore. This will be enough to straiten and make the bore round again. This is dependent upon any deep gouges or grooves you may have, that need to be removed.
I only seen one photo, which wasn't enough

so when i order a new piston it would be 1.00 over bore? because stock bore was 66.00 so one over would be 67.00?

one website says 1.00 over bore another is going in inches so in inches i would go .40?

MATH
 
A 67mm piston that is fitted (bored/honed) to what you have now (66 and 3/4 of a mm ) will clean up and straiten out the worn bore that you have now.

1mm = .040 thousandths of an inch
.25 mm (1/4 of a mm) is .010 thousandths of an inch.

YES! ... 1.00 mm = .040 thousandths.
You need a 1mm over size piston which will be 67mm...66mm is factory stock NEW.
 
Thank you!

So I paid 700 for it and I've ordered 800 in parts and will have to have it bored yet ... And I thought I got a deal lol but it's been fun learning

So this is what I've ordered
- wiseco bottom and top "complete"kits
-brand new case side
- lots of oem parts that I lost or thought looked like needed to be replaced ( drain plug, studs, vibration absorbers) things like this found a great site that has almost every oem part
- oil block off kit so I can do it right along with other oem parts from kens sight (watched all his videos awsome info)
- tools
- new bolts

I'll be back when I get it back together!!
 
well i got my cylinder done at a local Yamaha dealer here in st. louis that does the work in shop. total for bore and pro x cylinder was 190 i thought that was a lil high? but they did have it done in four hours.

so they told me they done make oe pistons in the size i need but that the pro x was oe? can someone explain this?

and do i need to do anything else to the cylinder before i bolt it on?
 
Its a hair on the high side, pro x piston is around $80/$90. Bore should be around the $60/$70 range.

Your only options for piston are Weisco, Namura, Prox, Wossen, Vitos. all with different pricing and material. '

New OEM or Cometic base gasket ONLY!! NO GREEN GASKETS!!!!
 
You have to wash the inside of cylinder. Sounds crazy , but dish soap and water. Wash it until a white cloth/paper towels come out clean when wiping the cylinder. Dry completely, immediately wipe cylinder down with oil.

This is to remove all micro particles from honing operation.
 
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New parts

Its odd to me that the shop went straight to 68.00mm when they have 66.8 wrote on the paper which is the math i came up with. I did tell them i came up with 67.00 for the new piston when i dropped it off but i also said ill leave it up to you since im not the pro. When i picked it up they didnt say anything so i thought they just used 67.00 i didnt catch it till i got home. He also stressed to properly brake it in because it has .002 clearance. I have watched kens video on how to do that.
 
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