Top end overhaul break-in

Discussion in 'Touring Models' started by dd1228, Aug 7, 2011.

  1. dd1228

    dd1228 Active Member

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    I just fininshed installing new pistons, rings, bored out cylinders (4.875 dia) , heads rebuilt etc. in my 02 FLHTC with 80K miles. My friend said to only run it for 20 seconds, then shut it off for an hour. Then run for 40 seconds and shut off for an hour. Continue this increasing 20 seconds each interval until 2 minutes then I can ride it. Then keep it below 3200 rpm and vary the rpm for the first 500 miles. Does this sound about right?
     
  2. Pilot77

    Pilot77 New Member

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    Its basically like breaking in a new engine. Your friend's advice will help to get the oil circulating thru the pistons and rings real good before you open it up. Its better to be cautious unless you want to rebuild em again.
     
  3. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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  4. Charlies Harley

    Charlies Harley Active Member

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    Good advice here, this is the advice I followed breaking mine in early this season, 7500km no issues yet.
     
  5. BUBBIE

    BUBBIE Well-Known Member

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    personally I would do the 30/60/30 times 10 method and It will break in On Both sides of the rings.. Then I would drive it easy but Not baby it and Not stay at one speed for any length of time... after about 250 miles you can do a little more RPM But not a lot... I like 500 miles on my new top ends\ before I ride it Normal and for Me , that is AB Normal:newsmile100:

    The Heat you have in Az. does the most damage to a new motor.... Keep it cool and stay out of stop and go traffic until the full break-in is completed.. is what I would do..

    I like the cool evenings or early mornings to ride a new motor and stay out of the 95/115 degrees IF possible..

    95" and lots of New found POWER....:D

    signed....BUBBIE
     
  6. R_W_B

    R_W_B Senior Member

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    Guys I have a question on this subject. When it comes time for this sort of thing, is it safe to only rebuild the top end with a 'repair bore' size or can you safely install one of these big bore kits on top of a low end that has a lot of miles on it ?
     
  7. BUBBIE

    BUBBIE Well-Known Member

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    I have seen Many go big bore(that is the 95" here) done after many miles.. Safe is a word that has to fit Each individual build and Motor....

    Are the crank and rods in good shape? along with the bearings.? If not it will show up early on with the problems, Like You are thinking about..

    I have done several builds with HD's with low to high miles on them...

    I did have a problem with one build at 40,000 miles and that was because of the front rod bearing ticking AFTER i went From a 10.5/1 ratio to a lesser 9.25 compression change,,, Loosing the whole motor for a complete rebuild with ALL new parts, from bottom up.... SO that told me it would of happened in the first place with the Bigger build in time...

    IF you want to feel safe, a New crank and rod assembly with new bearings will put your mind to ease SO be IT..

    BUT to pull the engine down (out) to get to all the EXTRA build is BIG..... The top end Is easily done in the bike so I'd take My chances...

    I'll do a 103" and Not touch the crank thingE and live with it that way... My run out on the TC96" is .0015 and that is Unheard of in this motor....

    But for now, I'm really Impressed with the New Found Power of the 96" stage one,,, TFI and Now using the SE 255 cams. CCP = 210 lbs in both cylds.(checked accurately with two different gauges)

    I will install a New Gen3 into this bike Before going 103 and report on that... and also the Gen4 When I Get one..... Hint hint...Dallas/Mark:D

    The oil I use is a factor for "piece of mind" as I'm Not wearing out my motor as quickly as with Lesser Quality oils..IMHO

    Now some builders are always changing out their motors for this cam or that and I doubt they do any BIG changes on OLD 80/100 mile motors, without checking the Condition of the crank/rod assembly..

    Lot of wasted dollars to do it wrong:53:

    signed....BUBBIE
     
  8. R_W_B

    R_W_B Senior Member

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    Thanks for that excellent and detailed answer Bubbie. Very informative. I know how to do a runout test, what other ways are there for checking the low end condition ?
     
  9. BUBBIE

    BUBBIE Well-Known Member

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    TUG PULL WIGGLE :D

    Were their ANY metal Pieces on the magnetic plug..EVER?. Rod or crank problem show early signs of METAL on the plug... Long slivers may mean the rod bearing is going.

    signed....BUBBIE
     
  10. R_W_B

    R_W_B Senior Member

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    Thanks, will be aware of above. And prolly in addition to the tug wiggle, if it's loud enough to be heard over the 07 primary chain whine then it could be a problem.

    I'm close to 16,000 miles so (hopefully) no worries right now. I did have some very small, short bits, not long, metal on the drain plug last oil change though. I communicate with the previous owner and he did overheat it once in a parade. Got so hot the CKP sensor gave out on him. But the bike seems to run strong and has good oil pressure, really just everything I ever wanted from a $10,000 investment about a year ago. It's my first Harley and would love to keep it and pass it on to my kids when I die, even if I get an Ultra in the meantime.
    Anyhow thanks again for the info.