1250 Unhappiness 2020 edition

[John Harper]

Originally Posted by Tomcatt

It seems this engine had oil consumption issues from day one with the 1250 top end.

I wonder if the 1, 2, 3, 4 minute break in, as opposed to Hammer's conservative break in of 10, 20, 30, 40 seconds could be a contributing factor? Running the engine (would you let it just idle?) with brand new pistons and cylinders for 4 minutes static, even with a fan (!), gives me the willies. Hammer's procedure seemed very prudent to me. Only time will tell.

John

[Tomcatt]

Originally Posted by John Harper

I wonder if the 1, 2, 3, 4 minute break in, as opposed to Hammer's conservative break in of 10, 20, 30, 40 seconds could be a contributing factor?

I dunno. "1, 2, 3, 4 minutes" is not something I'd do. Looking at the pics I think it's likely there were/are problems with the bores' surface finish. Then there's the butchered ring end gaps. Only thing that's for sure is it didn't turn out well.

[Turbo Sporty 48]

Originally Posted by Tomcatt

Only one ring had a tight gap, .012". It would be interesting to see pics of the ends of that ring. Pics would allow us to see if there's evidence of that ring butting up.

It seems this engine had oil consumption issues from day one with the 1250 top end.

Lousy ring seal and it still wet sumped. Seems blow-by didn't help scavenging much...

............

Regards oil losses, have the valve seals or heads been checked out?
Seems like multiple things going on
Obviously rings, but was bore correct? Butting rings and oil can still get by with a bad bore or honing.

[xLoneRiderx]

Originally Posted by wedge

About that crash bar cracking. Is this the first time you have had the bike tell you what to throw away? Harleys will get rid of extra junk on any bike and I live by the rule that once it gets thrown off I leave it off. Except for myself of course, it likes to throw me off too, but I figure that's just playful behavior.

...it likes to through you off! If you could see my belt collection! most of their buckles were deeply scratched. As you get older, the pavement is harder and harder so I'm getting everyday less keen to be thrown off my bike
That and ...my previous bike was a big 1982 Moto Guzzi California II and you know its v-twin motor is perpendicular to the driving line and always protect you when kissing the asphalt

[xLoneRiderx]

Originally Posted by brucstoudt

is this correct procedure for these pistons?i always measure near the bottom of the skirt 90 degrees from the wrist pin.

Sure it is! These are CP Carrillo pistons.

For Wiseco (at least those for 883-1200 conversion) you have to go to the skirt bottom for a real measurement, as per their Instruction sheet.


(mistake: 900 should say 90º)

[xLoneRiderx]

Originally Posted by Turbo Sporty 48

Regards oil losses, have the valve seals or heads been checked out?
Seems like multiple things going on
Obviously rings, but was bore correct? Butting rings and oil can still get by with a bad bore or honing.

Put new high-quality Viton valve seals during assembly (those blue rubber with small ring spring). Also did a fine valve lapping and checked them for air-tight seal by pouring gas into the ports. I believe nothing wrong in the heads imho.

[xLoneRiderx]

Originally Posted by Tomcatt

Only one ring had a tight gap, .012". It would be interesting to see pics of the ends of that ring. Pics would allow us to see if there's evidence of that ring butting up.

Here you are a bunch of ring tips photos:

Tips of .012" (Front top ring):



Tips of .018" (Rear top ring):



Tips of both second rings: