Cylinder Bore Surface Finish

[TPEHAK]

Hello. I have a question about honing the cylinder bore on 2009 Buell XB12Scg with 20000 miles.

Manual says when you reassemble the cylinder and piston with new rings you need to hone the cylinder bore to achieve 60 deg crosshatch pattern. But original crosshatch pattern angle on my cylinder looks much smaller, maybe about 30 deg, not even 45 deg like the most common angle for hone patterns.

Is it manual mistake? Should I hone with the same angle or hone with 60 deg over the original crosshatch pattern?

Here is a picture of my cylinder with original crosshatch pattern.

 

[user_deleted]

Manual says when you reassemble the cylinder and piston with new rings you need to hone the cylinder bore to achieve 60 deg crosshatch pattern.

THAT recommendation assumes you're using a dealer supplied OEM ring kit. the cross-hatch finish and specific angles totally dictated by the manufacturer of the rings used during motor rebuild.
if you're asking questions like this now and doing the rebuild yourself i truly feel sorry for that poor motor.

 

[TPEHAK]

But why in this case the original pattern is less than 60 deg? Did they assemble motorcycle with different rings? Is it OK to hone the cylinder to different angle than it was originally? After this there will be two patterns with two different angles.

 

[Silverrider]

What does the top of the piston look like??

 

[Cooter]

The purpose of the crosshatch isn't diminished by the narrow angle deviation. Crosshatch to 60*. Just like the manual states.

 

[TPEHAK]

What does the top of the piston look like??

The top of the pistons had around 1 mm thick hard deposits. The piston rings grooves was very clean, no any deposits in the rings grooves at all.

I soaked them in Aircraft Remover to clean the piston top.

 

[njloco]

I've seen a lot of pistons in my time, I've never seen that much carbon on any of them, in fact, that's more carbon than I've seen on all of the pistons I've seen put together ! Why would that be, I mean what would cause that ?

 

[Silverrider]

I've seen a lot of pistons in my time, I've never seen that much carbon on any of them, in fact, that's more carbon than I've seen on all of the pistons I've seen put together ! Why would that be, I mean what would cause that ?

There are many reasons for carbon buildup, Most carbon buildup is from oil getting past the wiper rings on the piston. Rather common on a high mileage engine. Can also occur from an excessively rich mixture, but that is very rare on a modern fuel injected engine with electronic ignition and controls.

Another source is a bad PCV valve that can suck excessive amounts of crankcase gases into the intake system.

 

[TPEHAK]

I'm sure if you take a look in your Buell cylinder at 20000 miles you will see the same. Maybe this is how Buell build motorcycles, with bad seals, and there is nothing you can do about it. Here is first random picture from Google search

 

[user_deleted]

I'm sure if you take a look in your Buell cylinder at 20000 miles you will see the same. Maybe this is how Buell build motorcycles, with bad seals, and there is nothing you can do about it.

 

[BuellyBagger]

I'm sure if you take a look in your Buell cylinder at 20000 miles you will see the same. Maybe this is how Buell build motorcycles, with bad seals, and there is nothing you can do about it. Here is first random picture from Google search

And just how are there 70k miles plus bikes on there original engine? Plenty of Harleys out there with near 200k never opened up. Hell my completely inferior 75 ironhead didn't look like that when I looked inside. I don't know why you're still rebuilding the damn thing if you've written it off as such a piece of s#!+? Just get rid of it and build your own bike damnit. F@#&

 

[TPEHAK]

I am not rebuilding it, I am just changing leaking pushrod cover o-ring.

 

[Outlaw]

You have it down that far and can SEE the need for overhaul . If you don't do it you lose your right to ever complain about that bike.

 

[TPEHAK]

Check this out

before

and after

 

[Outlaw]

Yes. It's very clean. Now fix what caused it. Your bike will be much happier.

 

[Silverrider]

Good time to give your motor a little more power

1275 big bore kits,

http://www.hammerperf.com/xlbigborekits.shtml#1275packages

 

[AZmidget91]

And now this engine will never run right again. Guarantee the rings don't seal no matter what crosshatch you put on it. It is not advised to remove the piston from the cylinders without boring the cylinders to ensure they are round again.

 

[AZmidget91]

Proper way to clean pistons

 

[njloco]

I don't know why you even bother with buell motorcycles ? Your always putting them down but then coming up with innovative things for them ? No sooner do you come up with something new for then your putting down the machine you made it for ?? I don't know if your aware of it but, your a bit strange. I don't say this in a negative way but maybe you should go talk to someone. Believe me, for me to say this to someone, they have to be a little off someplace because, I've seen a lot in my visit here on earth.
I hope you don't take this the wrong way.

Go see someone, please, you have issues !

 

[njloco]

AZ, I see you left the pistons in the cylinder, did you then use a chemical to clean them or some mechanical device ? Also, why go through all of that with out installing new rings, along with the honing?

Inquiring minds would like to know ?