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Yes

As pictured, those bearings definitely need to be replaced.

Yes, use Plastigauge to measure your tolerance on them. Make sure you torque the rod caps to specifications before reversing to measure the Plastigauge.

Having said that, the surface in the picture has babbit material missing. That means if you measure with Plastiguage you will also need to re-measure with Plastigauge when you install the new bearings to make sure they are not too thick and don't meet specs for tolerance.
 

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Discussion Starter · #5 ·
hey heater you make great point , i never thought of that can i ask you then how would i measure everything out to get an idea of what size is needed to order since the ninja has three sizes to choose from ?? i got the haynes in the mail today so hopefully i can get some more ideas ,, this is holding up my entire rebuild lol
 

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The best way is to use a micrometer to measure each crankshaft journal. Personally, that is what I would do. I realize you may not have felt like this item is something you want to go buy for your toolbox, but I guarantee you will have it paid for many times over the first engine you rebuild. You don't have to buy the supergonzo model for a gazillion dollars. But it has to measure out to enough decimal places for specification call outs for the journal specs.

You must have some tool suppliers that sell the lesser priced models out where you are there in Boston. Probably more than we have out here in the Seattle area.

Compare your measurements to specs to determine the correct bearings to order. THEN you would use the Plastigauge to measure clearance with the bearings to make sure they are correct. If you measured properly, all should be well, however. Take three or more measurements on each journal to make sure you have good measurements to use to order the thickness you need for bearings. The real purpose of Plastigauge is to make sure you do not have too little clearance in what you install. Too little = toasted parts very quickly.
 

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Just looking at those shells, I would think the crank journals are trashed, too. If so, they would need to be turned down and re-polished. Checking the nominal sizes of the journals at several different points will tell you how far they will have to be turned and that will tell you which undersize bearings to buy. Then and only then you can do a dry assembly and use plastigauge to check the clearances.
 

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Discussion Starter · #8 ·
The best way is to use a micrometer to measure each crankshaft journal. Personally, that is what I would do. I realize you may not have felt like this item is something you want to go buy for your toolbox, but I guarantee you will have it paid for many times over the first engine you rebuild. You don't have to buy the supergonzo model for a gazillion dollars. But it has to measure out to enough decimal places for specification call outs for the journal specs.

You must have some tool suppliers that sell the lesser priced models out where you are there in Boston. Probably more than we have out here in the Seattle area.

Compare your measurements to specs to determine the correct bearings to order. THEN you would use the Plastigauge to measure clearance with the bearings to make sure they are correct. If you measured properly, all should be well, however. Take three or more measurements on each journal to make sure you have good measurements to use to order the thickness you need for bearings. The real purpose of Plastigauge is to make sure you do not have too little clearance in what you install. Too little = toasted parts very quickly.
i actually have a micrometer :runaway i wasnt sure that was the right tool for the job and i can agree it has already paid for itself in other ways and thank u for the reply the way you explain it makes it alot easier ive been twisting my brain trying to think of the proper way to get this done
 

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Discussion Starter · #9 ·
Just looking at those shells, I would think the crank journals are trashed, too. If so, they would need to be turned down and re-polished. Checking the nominal sizes of the journals at several different points will tell you how far they will have to be turned and that will tell you which undersize bearings to buy. Then and only then you can do a dry assembly and use plastigauge to check the clearances.

i was thinking the same thing but im assuming this bike was apart recently and A. either reinstalled improper bearings or B reused old bearings with new parts (i will micrometer and feeler gauger the whole thing tomoro and post results)

HERES A FEW PICS im not sure if you can tell anything but it doesnt have any major signs of wear on the crank just the bearings


 

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Some variation in shade as shown in pictures one and two is OK as long as you can't feel any variation in the surface when you run a finger or finger nail across the width and it mic's out OK. The service manual will tell you the tolerances for the journals in terms of wear. They can wear evenly and if no defects you can use oversized bearings as long as you micrometer the journals to make sure the wear is not excessive.

Babbit material missing on the bearings does not necessarily mean the crankshaft journals need machining. If you are not set on taking the engine down that far, I would just try to get the right bearings in it for now, bearing in mind (no pun intended) that eventually the crank may have to have an appointment with the machine shop.
 

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Discussion Starter · #11 ·
thanks heater :clap:clap:clap

the advice helped out a ton from what ive read from here and the manual i hope i ordered the right parts should be in monday morning and will post the good word in the afternoon
 
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