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Buell Forum » Knowledge Vault (tech, parts, apparel, & accessories topics) » Engine » Big Mechanicals: Head, Cyl, Piston, Rod, Crank, Flywheel, Cases, Bearings » Not a very good start « Previous Next »

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Harleyms
Posted on Tuesday, April 12, 2011 - 06:04 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Referencing these two threads will give a little back story http://www.badweatherbikers.com/buell/messages/476 23/622636.html?1301894421
http://www.badweatherbikers.com/buell/messages/476 23/625558.html?1302290179

So I tore the top end of the engine down today. The valve seals might have been a factor....but it would have been a small one. This is what I saw when I pulled both the jugs off...

the grooves in both the cylinders are from the piston pins. Both front and rear pistons were missing the cir-clip out of the same side (left if you are on the bike) and had gouged the jug. I'm going to guess that the gouges are at least .020-.030 deep. I could understand it better if it would have just been one, With 2700 miles on it I don't see how both cylinders could do this. Maybe engine assembly with a hangover and they were forgotten? As nice as a big bore kit sounds I can't afford one. I see a few jugs on ebay, some new some used but all singles would anyone have a part number for a '98 S1W cylinder and could you also tell me if they are pre-machined or will I need to have them honed to fit my pistons? Or does anyone out there have a set of low mile cylinders that they want to sell me reasonable so I can get this poor bike back on the road?

The wife's not gonna be happy : (

(Message edited by harleyms on April 12, 2011)

(Message edited by harleyms on April 12, 2011)
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Pkforbes87
Posted on Tuesday, April 12, 2011 - 06:49 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Just a shot in the dark here.. but I've got a spare rear cylinder from a 2002 X1. The front cylinder from the same bike is toast, or I'd send you the pair. Anyway, if you can find a matching front cylinder, let me know and what's mine is yours for the price of shipping.

The cylinder is the bare aluminum color by the way, and had exactly 6671 miles on it when torn down.
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Essmjay
Posted on Tuesday, April 12, 2011 - 10:17 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Take them to a local shop that bores and have them check. You may be able to bore them out 30 or 40 over and just buy new pistons.

Shane
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Jramsey
Posted on Wednesday, April 13, 2011 - 09:28 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Harley,you have a reply in the classifieds.
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Pammy
Posted on Wednesday, April 13, 2011 - 11:48 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Maybe the clips weren't left off. Maybe they were pushed out. Have the rods checked or check them yourself to make sure the crank is sitting straight.
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Pammy
Posted on Wednesday, April 13, 2011 - 11:50 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Maybe the clips weren't left off. Maybe they were pushed out. Have the rods checked or check them yourself to make sure the crank is sitting straight.

I'd like to see the pistons (inside and out). Left side, of course.
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Harleyms
Posted on Wednesday, April 13, 2011 - 12:44 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I just took some rough measurements last night but the way I see it the pin boss recess doesn't come out of the cylinder liner at bottom dead center. So if the retainers were in there and had come out during operation in my opinion and experience (automotive, this is my first Harley engine) the retainers would have eaten the side of the piston as well as the rings and made a bigger mess of the cylinder wall as the piston was traveling through it's motion. The only damage to the pistons are a slight nick in the skirt from contact with the gouge. The rings all look good, there's no chipping of the ring edges or surfaces (surprisingly) and yes I realize I should go ahead and replace them but at the moment the budget doesn't allow for that. If I can put it back together and get a couple seasons out of it then I'll be happy and in the mean time I'll buy parts for a rebuild.

on to the pictures, the first two are the front cylinder piston


These are of the rear cylinder piston


I only got the underside of the rear piston but they both looked the same


the discoloration between the ring lands appears to be just cosmetic.

as far as checking the crank to see if it is sitting straight I assume you are talking about using a straight edge or calipers to make sure the crank counter weights are parallel? They visually appear to be but I haven't measured anything yet
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Pammy
Posted on Thursday, April 14, 2011 - 10:21 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Make sure the rods are perpendicular to the bore. Not leaning to the one side. I have seen this happen a few times. My own as a matter of fact.
There is a long pin that you put through the small end of the rod and rotate the crank until the pin rests on the surface of the case. Then you check the clearance on either side of the pin where it meets the case.
If the crank/rod deviates from centerline, it will "screw" the wrist pin out of the rod and cause the issue you are having.
Not a definitive diagnosis just from pictures but certainly a viable possibility.
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Cymro
Posted on Monday, October 31, 2011 - 03:54 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Any sign of damage on the wrist pin?
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