EVO All Evo Model Discussion

Base gasket rebuild, thoughts?

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Old Mar 31, 2014 | 11:48 PM
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Default Base gasket rebuild, thoughts?

SO...I decided to bite the bullet and do the base gaskets myself. Nasty oil drips under the bottom, marking all the parking spots I use, oil bubbling up at LEAST from the L rear jug. Hope this is the cause of all my leaks at this point. Had the rocker box leaks before, solved them about 20K miles ago, never happened again.

Got the first head pulled apart today. Photos attached are from the front cylinder. Since I'm new to this level of detail on any engine, I was wondering if you all you pros out there could comment on a couple of things.

1) How do the valves look from below? There is a pic of the valves in place in the head. Should I replace them - and do the stuff that goes along with it - or can I just decarbonize them and put 'em back. I haven't done any measuring yet.

2) How does the piston look? I've seen a couple of pointers on how to tell wear by carbon pattern, but none of the seems to fit. Should I pull it and clean it - or do they get replaced?

3) This bike has 65K miles on it, and it looks like this is its first head job. The induction module is filthy. I thought about taking all the electronics out of it and soaking it a solvent, probably gasoline. Any thoughts on that?

4) I think the cylinder itself looks pretty good I am planning on replacing all three rings on both pistons since I have it apart. From the looks of the piston, should I do anything else? Hone it out?

5) Would it be worth it at this point to take the heads to a machine shop and have them cleaned and polished off, and do all this valve & honing work?

6) Here's what I'm replacing anyway: Fueling head studs and bolts (kit); James top-end gasket kit; Hayden Enterprises "The Oil Fix"; Andover Coils 12V coil; 8.8 mm Accel Custom Plug Wires; NGK Iridium IX plugs; Hastings standard size piston rings; and some other various & sundry items.

Thoughts are much appreciated!!
 
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Old Apr 1, 2014 | 12:29 AM
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At those miles (and looking at that scungey piston) I would re-bore it and be done with it. Valves need to come out and have seats and guides assessed. Get a proper angled seat cut and I probably wouldn't bother with the "oil fix" as Cometic or James gaskets will fix that anyway.
 
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Old Apr 1, 2014 | 08:26 AM
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I redid my top end a couple years ago on my bagger. I used the hayden "oil fix" kit when I put her back together. Maybe that wasn't what truly fixed it. I also rented the trock cylinder lapping plate from the local indy. I lapped in my valves with lapping compound and the suction cup stick thing. No more base gasket leaks and she runs great. If I had the money a valve job would have been the way to go....
 
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Old Apr 1, 2014 | 08:56 AM
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Before I answer your question I need you to answer mine.
What is your budget?
 
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Old Apr 1, 2014 | 09:35 AM
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Personally, I think you have options. If your budget is tight it looks to me like you could bolt it back together and ride for another few years. But, if you have the cash and the time might as well do a complete top end. My unschooled thoughts are that there are a ton of EVOs out there with way, way more miles than yours that have never had the top end apart, or have just had the base gaskets replaced. Yours is a late model EVO so many of the early EVO issues like porus metals don't exist. I think you can pretty much do what you feel like doing on this one.

With that said I'd wanna know if it was smoking, burning oil, losing compression, etc.. If it were mine and had no issues before you tore it down and the cylinder walls looked good, pistons looked good, valves, etc.. I'd probably bolt it back together.

What I'm saying is, once you've covered the critical things everything else is gravy. I realize that some folks will feel differently. My philosophy is, if it ain't borke don't fix it (or it may really be broke). The stock evo, if properly jetted, etc.. will go a very long way without major work (save the stinking paper HD base gaskets).
 
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Old Apr 1, 2014 | 10:35 AM
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The sides of that piston looks like it had some blow by!
 
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Old Apr 1, 2014 | 01:49 PM
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Budget is tight but not stingy. Don't need a lot of power. This is my primary commuting vehicle, so I want long-term reliability, good economy & enough power to blow by those slow-poke jackasses that go 30mph on a two-lane 55mph highway with limited passing lanes. Plus I really want to clean only road dirt off the bike after every trip ... not leaking motor oil!
 
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Old Apr 1, 2014 | 01:51 PM
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Originally Posted by SteddyTeddy
The sides of that piston looks like it had some blow by!
That's what I suspected, which is part of why I posted the pics to begin with.

Sounds like - at minimum - a hone and new rings?
 
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Old Apr 1, 2014 | 02:05 PM
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Originally Posted by dhbmedic
That's what I suspected, which is part of why I posted the pics to begin with.

Sounds like - at minimum - a hone and new rings?

You're assuming that whoever worked on it last got the cylinders right.
I would say to be safe go 10 over with new pistons and new rings.

Cometic makes a complete kit for redoing your top end.
I don't remember what it costs but it might be worth looking at compared to the cost of the James and Hayden set.

If you want that little extra oomph get rid of the stock cam and put in a better one. That will do a lot for your performance.
 
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Old Apr 1, 2014 | 02:05 PM
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I'd have the jugs checked with a bore gauge. If there is scoring or jugs are tapered then it should be bored. In the middle of putting mine back together now. Was $267 for new pistons and boring through Cycle Rama in Clearwater FL. Mine were out past the specs in the manual and my pistons still didn't look as carboned up as yours.
 
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