Author Topic: what y'all think bout these pistons?  (Read 4611 times)

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brownb56

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what y'all think bout these pistons?
« on: June 19, 2005, 04:25:52 PM »
Are these worth trying to clean up and reuse, looks mostly like surface rust but i'm not sure.
« Last Edit: June 25, 2007, 05:18:46 AM by Glenn Stauffer »

brownb56

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Re: what y'all think bout these pistons?
« Reply #1 on: June 19, 2005, 04:31:04 PM »
here's a look at the cylinder walls too
« Last Edit: June 25, 2007, 05:21:10 AM by Glenn Stauffer »

brownb56

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Re: what y'all think bout these pistons?
« Reply #2 on: June 19, 2005, 04:34:23 PM »
and the valves aren't much better
« Last Edit: June 25, 2007, 05:23:19 AM by Glenn Stauffer »

Offline Tim.

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Re: what y'all think bout these pistons?
« Reply #3 on: June 19, 2005, 04:34:49 PM »
Well, right off the bat you will need new piston rings and hone the cylinders.

The real answer to your question lies in the cylinders.  You may find they need to be more than just honed.  If they need a bore, you need new, bigger pistons.

You should take your pistons and cylinders to a machine shop to get an estimate on honing.  If they look at them and laugh, you'll know you need a bore and new pistons  ;D

Are you trying to do this on the cheap, or are you wanting to invest some money in the ride?  An alternative is to locate a decent set of pistons/cylinders on eBay or the like.

You might also want to consider starting fresh with a different engine.  It sure looks like you should be tearing the bottom end of the engine apart.  What does it look like down there?  Was there oil in the engine?

An entire engine often sells for very little $ on eBay, as nobody wants to ship.  If you get lucky and find one within driving distance of you, you might think about picking it up.  Better yet might be an entire parts bike.  You need new wheels for sure, and new shocks.  You might find an entire bike for less than you'll spend on the wheels, suspension and other bits you need.
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brownb56

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Re: what y'all think bout these pistons?
« Reply #4 on: June 19, 2005, 04:39:44 PM »
thats what i've been thinkin, a guy i work with has a similar one says its been sittin in a garage for the past to years, says he gave up on it when he couldn't get any fire at the plugs. If i get that one this would make a good parts bike.

Offline Tim.

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Re: what y'all think bout these pistons?
« Reply #5 on: June 19, 2005, 04:45:13 PM »
YEAH!  In a garage - my three favorite words!  Get it - same model as yours?  Getting spark is relatively easy.  What you're looking for is 'good bones' and your bike, I'm sorry to say, looks like it has osteroperosis.
Roule comme dans les années 70...   Roll as in the Seventies...

brownb56

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Re: what y'all think bout these pistons?
« Reply #6 on: June 19, 2005, 05:08:00 PM »
bottom end had oil in it looks good, other than a new clutch i think it would be fine. some jackass left plugs out of the engine and well you see what that led too.

Badboy

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Re: what y'all think bout these pistons?
« Reply #7 on: June 19, 2005, 05:17:29 PM »
Where would all that rust come from,and that color? I wuold say that if the bore is good ,clean up the pistons and use them,it all depends on how much wear. Did someone have a neighbor that didn't like him? Looks to me that something got in there that is not supposed to be there.

brownb56

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Re: what y'all think bout these pistons?
« Reply #8 on: June 19, 2005, 07:40:11 PM »
only 12,000 miles on engine and I couldn't really see much wear,tryin to spend as little as possible right now but I also want it to run right.

Offline TwoTired

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Re: what y'all think bout these pistons?
« Reply #9 on: June 20, 2005, 01:40:26 AM »
Pretty much agree with Tintin on the assesment. The pistons are aluminum.  So, they don't rust. But, they can corrode, and that is usually white in color.  The rings are unuseable.  The ring lands in the pistons can be damaged by the expanding rust of the rings.

The real issue is the cylinder walls.  These will have to be, at least, honed.  After honing to good base metal then measured.  If still within serviceable limits, they can be reused, with perhaps the old pistons if they examine well after cleanup.  If not, then bored to the next over size.  But, you should find a set of pistons and rings for it first, and have it bored to fit them.

As for the valves, the surface rust shown doesn't bother me.  But, the valve seats and valve mating faces should be carefully examined after cleaning.  They may need regrinding and lapping on number one.  And you may as well address the others while broken down to this stage.  Just remember that if you take parts out of the assembly to note where they came from so they can be assembled in the same positions they were before, as the bearing surfaces have already worn as a mate.  In other words, don't move valves from cylinder to cylinder, for example.
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Offline MRieck

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Re: what y'all think bout these pistons?
« Reply #10 on: June 20, 2005, 05:19:44 AM »
I'd say those pistons are junk. So are the valves. You might be able to use the head if the rust hasn't penetrated to deep into the seats. You might be able to bore it out BUT Mark McGrew from M3 racing and I were talking about this the other day. Sometimes the corrosion goes so deep(like worm holes) that it junks the sleeve and no matter how much you bore it it will not work.
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brownb56

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Re: what y'all think bout these pistons?
« Reply #11 on: June 20, 2005, 09:45:26 AM »
this setup would work for mine woudlnt it

Honda CB500 Four Big Bore Kit 605cc performance rebuild kit

Offline SteveD CB500F

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Re: what y'all think bout these pistons?
« Reply #12 on: June 20, 2005, 12:08:36 PM »
Yes but you'll still need a head.
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Offline MRieck

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Re: what y'all think bout these pistons?
« Reply #13 on: June 20, 2005, 12:56:58 PM »
Yes but you'll still need a head.
...a ported head to feed those larger cylinders. ;)
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Offline Tim.

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Re: what y'all think bout these pistons?
« Reply #14 on: June 20, 2005, 02:53:00 PM »
I can't remember, is it a 500 or 550?

I'd skip the 605cc kit.  Save some money and go for the 555cc kit (especially if it's a 550).
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brownb56

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Re: what y'all think bout these pistons?
« Reply #15 on: June 20, 2005, 04:06:31 PM »
its a 550 but thats the only kit i have found so far, been try to find some websites that carry piston kits but haven't had any luck. wen't all through the list in the faq section.

Offline Tim.

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Re: what y'all think bout these pistons?
« Reply #16 on: June 20, 2005, 05:30:15 PM »
This is the kit, from the same seller that I have in my CB550F now.  I've put 200 miles on it in the last 2 days and everything is perfect.  This works out to a 0.5mm overbore on your cylinders.  Well within factory spec, so nothing else special is needed.  Just get your cylinder head cleaned up, new valve seals etc. and slap it back together.

Now, you should still take your cylinders to a machinist to ensure you can get away with a 0.5mm overbore.  You should be ok, but if they're really bad, you might need to go bigger.  In that case, check out www.servicehonda.com for pistons/rings at 0.75 - 1.0mm over.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4557673831
« Last Edit: June 20, 2005, 05:32:28 PM by tintin »
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brownb56

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Re: what y'all think bout these pistons?
« Reply #17 on: June 20, 2005, 05:52:29 PM »
I really do appreciate all the help but I think the best thing to do right now is pack up all these parts and put them aside for now :'( . Gonna try to find one that is in a lill better shape, my girlfriend's dad has one sittin in a garage just goin to waste. Maybe he'd let me have it as a wedding gift  8)

Badboy

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Re: what y'all think bout these pistons?
« Reply #18 on: June 20, 2005, 06:26:04 PM »
Well, like I said,it will depend on if the pistons will clean up and how the cylinder walls are. If it were mine I would clean up the worse piston and see what that looks like and then see what the walls look like. A factor in this is how much money you want to spend etc. I have rebuilt hundreds of auto engines and a few other types ,it is hard to make a sound judgement from pictures. On the other hand there is no point in doing a half of a job and having to do it over.Pistons are usually tough,and can take a lot of beating[look what they get on the road]! I still wonder about the red color,was the engine froze up? If water got in there,you want to wirebrush the walls and see if there is a pitted ring where the top- of the pistons were.If that is to deep,than a rebore.

brownb56

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Re: what y'all think bout these pistons?
« Reply #19 on: June 21, 2005, 03:18:45 PM »
I got some fine emery cloth to clean stuff up with and yes the motor was locked up. The plugs were left out of the engine for god knows how long, and the two outer plug holes are stripped. Carb was laying on the ground with the float bowls off of it, and it is completely rusted up. Just not sure if its worth spending the money to fix everything on this one or find one in a lill better condition and use this one for parts.

Offline MRieck

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Re: what y'all think bout these pistons?
« Reply #20 on: June 22, 2005, 04:30:22 AM »
All junk at this point.
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Badboy

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Re: what y'all think bout these pistons?
« Reply #21 on: June 22, 2005, 07:23:54 AM »
Yes ,I would say that it would be a tough job. Why do people do this to a good machine?  They should be flogged! Maybe I should not talk to loud,but I kept it covered for a while. Didn' leave the plugs  out though.