440 bigbore 52mm, or 54mm?

[Mastermind]

I've yet to ever see any BB kit that was worth using.

Some standard bore kits are ok........but there are many more that are not.

I've read the whole thread....and it's plain to see that you don't want to hear what is being told to you by people with vast experience.

Get a BB kit and have a great life.

 

[Greenclimber]

I'm going to just go with that the dealer told me to do... Which was run it until it doesn't run anymore. Then spend money on it by getting a 50mm piston. Which is the cheap and easy way to do it.

 

[hseII]

You would be better off ordering parts from a reputable forum sponsor. They have the parts you need and none of the crap that goes along with fleabay.
Stick with a meteor piston.
Reuse the piston pin clips, the am clips are mostly junk.
If there is transfer on the cylinder use some hydrochloric acid that you can get from a hardware store to clean the cylinder walls.
Thats about all I have without getting really in depth.

Others will chime in to help you with your decisions and other options.

And lastly were you able to determine the reason the saw was not running correctly?
I'd hate for you to spend money on fixing the saw and not find the cause of the problem first.

Yes.
Cause cleaning up a cylinder and putting a new set of rings in a saw, only to trash the OEM piston and rings due to an air leak SUCKS

 

[hseII]

I'm going to just go with that the dealer told me to do... Which was run it until it doesn't run anymore. Then spend money on it by getting a 50mm piston. Which is the cheap and easy way to do it.

The cheap and easy way is to stop using it now, get the issue fixed, and then halve rings installed; either at your dealer, or by one of the site sponsors.

Ask Me How I Know; better Yet, see my above post

 

[Grande Dog]

Howdy,

Guess what, how many people buy aftermarket cylinders because their OEM failed? The logic behind this would have to be all OEM failures are operator error. The real problem is the vast difference in the quality of the AM parts. To top that off, no one AM parts seller has a complete line of quality parts. It makes it a real crap shoot getting what you pay for. I don't work for them anymore but, I did develop the NWP cylinder kits for Bailey's. The focus for developing these BB kits were to keep otherwise good saws from making there way to the boneyard because people didn't want to drop the price of an OEM top end replacement on their saw. I have no doubt in my mind that over the years these NWP kits have kept 10's of thousands of saws from ending up in the pile just from the shear numbers sold, and the low failure/return rates. Of course there's failures when you sell those types of numbers and there's pages, and pages on this site to look at on the subject. Here's what I'm saying, that for every one of the failures there was about 75 successes. To me, considering the cost, the NWP kit is a no brainer unless you're putting food on the table with your saw. If you are putting food on the table with your saw, and you actually wear out cylinder, smart money is with a new saw.

Regards
Gregg

 

[Mastermind]

I think that even if you find a good one.....in a certain box, the Chinese will start slipping crap in that box before long.

I've tested a bunch of different top ends. Like Gregg said.......it's a crap shoot. Sadly.

 

[griffonks]

Chinese top-ends are a crap shoot at best. The last time I got a Raisman because my parts supplier was out of everything else I couldn't get the circlips in the piston because the grooves in the piston were .010 too close.

I had to remove that much material from the end of a wrist pin.

Then the transfers and ports need to be cleaned up.

I wish you luck. It's true that it's a rarity when someone can learn from other's mistakes and experiences.

 

[Grande Dog]

Howdy,
Back when, Raisman had the lions share of their product manufactured in South America. At that point I would say their AM product was above average. You can tell by looking at the product now, it's being made East, not South. From what I've seen, they went for cost over quality.
Regards
Gregg