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engine blowby

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mike1969
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blowby

Post by mike1969 » Sat Sep 18, 2010 8:38 pm

Just wanted to give an update.
The head gasket came in. It was defective. A replacement is being shipped.

I have another question before I put it back together. I was setting the ring gaps on the pistons and noticed the the colors on the top rings of both pistons are now black and chrome colored. The top half of the ring is chrome color and the bottom half is black. That is the part of the ring that rubs against the cylinder wall.

I've never seen anything like this before. Is that the way that rings get when they are seating in the cyls.?

mike1969
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blowby

Post by mike1969 » Tue Sep 21, 2010 11:54 am

Another setback. I received the replacement gasket but it was for a 250 engine!

Sonofabitch!

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davomoto
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Post by davomoto » Tue Sep 21, 2010 12:12 pm

Bummer Mike! The two upper rings are different. I always have to look at the manual, but the chrome edge ring and the dark edge ring correspond to a certain groove. if you have a manual, it will tell you which is which. If not, let me know, and I'll post it for you.
davomoto
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jensen
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Post by jensen » Tue Sep 21, 2010 2:49 pm

Hi,

Just a word of consensus. Not only it is important to put the right ring in the right groove, but every ring has a mark. The mark should always be upward (on the top). Sometimes this mark is really hard to find, but it's there. Most of the time it also gives the size of the ring.

Before you put the rings on the piston, check the gap. Put the ring into the bore (with the piston to make sure that the ring is perpendicular on the axis of the bore), and then measure the gap with feeler gauges.

I never read something about it on the forum, but maybe I missed it. The rings should be placed with the gaps 120 degree's from each other.

Place piston pin clips in there groove were they belong, and turn the slot (gap) upward.

Maybe you knew this already, maybe not,

Jensen
assembly of Japanese motorcycles requires great peace of mind (Pirsig)

mike1969
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blowby

Post by mike1969 » Tue Sep 21, 2010 9:54 pm

Thanks for the tips guys. I have the rings with STD. marks up and spaced at 120 deg.. I didn't know the 2 upper rings had a specific order. Also didn't know about the piston pin clips.

Guess it was a good thing that I got the wrong head gasket. I can still check those things without tearing it apart again. This ordeal has been a real education for me.

jensen
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Post by jensen » Wed Sep 22, 2010 1:10 am

Hi,

Make sure that the gap (piston rings) is according to specs. If too small, then file (very carefully) the gap to specs. If the gap is too small, and the engine warms up, the piston rings will snap, or worse, destroy the freshly honed surface of the bore.

Jensen
Last edited by jensen on Sun Sep 26, 2010 1:10 pm, edited 1 time in total.
assembly of Japanese motorcycles requires great peace of mind (Pirsig)

conbs
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Order of rings

Post by conbs » Thu Sep 23, 2010 2:00 pm

According to Bill Silver: Oil ring on the bottom. Dull ring in the middle. Chrome ring on top. Thanks Davomoto. I had forgotten that one.

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