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I pulled my Throttlebodies cleaned them and put in new injectors. once I put everything back together the bike was blowing blue smoke out of both exhaust pipes. I did a wet and dry compression check on the cylinders and found #2 and 4 below the mins dry, wet they perked back up. So I pulled the engine out of the bike and ripped it apart. The head is in the shop getting an overhaul and I am ordering rings for the pistons. No damage to the cylinders so I plan to hone them and re-ring the pistons. The cams Mic'd out with in tolerance and the machine shop is making sure everything is per spec on the head.
Question is do I need to put in new rod and crank bearings?

Any help you can give would be appreciated (except telling me to get a new engine or a new bike. I'm in Hawaii and shipping is outrageous.)
 

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The cylinders on this bike are Nikasil I believe. You can't just home them like a iron sleeve cylinder. If the engine has low miles you should be able to use just a red scotch brite pad and scrub the cylinders and use new rings but I doubt its a low milage bike. The GSXR1000 I just rebuilt had 7500 miles on the Nikasil cylinders and the rings seated just fine. I would call a shop who specializes in Nikasil coatings and see what they think. You may have to have them recoated if the wear is great. They would also have the proper equipment to hone. As for the bearings you should check them(rod and main) with Plastigage. That is the only way to determine how much wear you have.
 

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How many miles?
 

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The cylinders on this bike are Nikasil I believe. You can't just home them like a iron sleeve cylinder. If the engine has low miles you should be able to use just a red scotch brite pad and scrub the cylinders and use new rings but I doubt its a low milage bike. The GSXR1000 I just rebuilt had 7500 miles on the Nikasil cylinders and the rings seated just fine. I would call a shop who specializes in Nikasil coatings and see what they think. You may have to have them recoated if the wear is great. They would also have the proper equipment to hone. As for the bearings you should check them(rod and main) with Plastigage. That is the only way to determine how much wear you have.
Follow this advice... do not hone the bores, the Nikasil is only on there .oo2-3" thick. Recoating is an option but not cheap (quote here was $800). I personally would not have torn this engine down.

You most likely had valve seal issues, replacing the guides and seals will likely fix you up. What was the mileage on this bike?
 
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You most likely had valve seal issues, replacing the guides and seals will likely fix you up. What was the mileage on this bike?
He said compression went up wet which indicates rings not valve seals.

But does suggest he quickly tore the engine apart before attempting to unstick the rings. Then announced plans to hone the cylinders without looking close enough to realize they are plated.
 

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Compression always goes up warm and wet. Didn't say the readings before and after... doesn't mean the rings were bad, coulda been normal. Is this a high miler engine? Has anyone heard of an FJR that "wore out it's piston rings" or had stuck rings... especially an oil ring.

Valve seals on the other hand have little to nothing to do with compression. Some may remember '04-'05's had a valve guide problem which prematurely wore out valve seals.
Much more data required to nail this down. Pics of the opened up engine would help too. Now that he's got it apart he can tell us if he has stuck rings.
 

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Valve seals on the other hand have little to nothing to do with compression. Some may remember '04-'05's had a valve guide problem which prematurely wore out valve seals.
Much more data required to nail this down. Pics of the opened up engine would help too. Now that he's got it apart he can tell us if he has stuck rings.
The O.P. appears to be a One Post Wonder.

Builders of race engines often skip installation of valve seals. Most all the valve seal does is keep oil from running down the valve stem while the engine is not running.
 
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Compression always goes up with any liquid in the cylinder.

Its the actual numbers that mean something. Some engines, especially over square ones are heavily influenced by the throttle valves. Yamaha requires either the throttle held wide open or the throttle bodies removed for a compression test.
 

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To the original question, why would one ever go that far into an engine without replacing Crank and Rod bearings ? Are they ridiculously expensive or something ?
 
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