I had a remanufactured engine from the Moco that failed 6,000 miles in. That motor was never right from day 1. It was a bear to start, overheated at the drop of a hat and developed no power. It was also the QUIETEST Evo I ever heard-until it threw a wrist pin bearing at 6,000 miles. Fortunately, it was under warranty. The dealer sent the motor back to Milwaukee, and though H-D never explained what went wrong, it came back with a brand new (not rebuilt) top end. I suspect the piston/cylinder clearance was too tight on the first rebuild. JUst because the Moco put it together, doesn't always mean it will be perfect. That's why warranties exist.

The second rebuild was noisy as all get out, but ran cool and strong like a fully broken in motor from day one. Today, I have 75,000 miles on that motor, and it runs like a champ.

To this day, I don't quite trust a "quiet" Evo.

 

just wanted to say thanks so much for your direct and informative answer to op's situation. With those two simple sentences, my man got the confirmation that he was right in his diagnosis. Thanks again for a great to the point answer!

 

I hope the Doc is still around.

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For ROCKOUT information & purchasing please click the LINKS below... For all Twin Cams and Evo Big Twins & Sporsters

 

He is.

 

He definitely seems like a knowledgeable person and not just a braggart or just full of opinions. Like I said, my man and I really like and appreciated his to the point response....confirmation on sam's thought bout his 79 shovel ☺ I too hope to find more answers from him or others like him when other questions arise. First day joining and already amazing help..and I didn't even have to post the question! I'm going to love this forum��

 

Someone don't hang out in EvoLand much.... Ya'll are makin' me blush.

 

Glad to see you're alive & well

I made the comment 'cause it was a 7 year old thread, lots of people move on.



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For ROCKOUT information & purchasing please click the LINKS below... For all Twin Cams and Evo Big Twins & Sporsters

 

This came up as a search result and was exactly what we needed...I didn't even think to check how old the thread might be, hahaha!

 

Did you have this problem on a '79 Shovelhead? That's a whole other story. I had a '79 FLH POS, and know about their issues very well. What I heard, back in the day, was that the MoCo was "experimenting" with different materials for valve guides. They sent a bunch out with different kinds of guides and waited to see how many blew up. So, MANY of the 79's dropped a valve. If you have one and it lasted this long, that's amazing by itself. Unless it has already been rebuilt (a top end only lasts about 25K miles on a shovel) and the last person screwed up the guide clearance.