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Old 08-04-2012, 08:20 AM   #316
Mike V.
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Curious what you guys think of Benthic's receding carbon build-up pattern on the top of his piston in the picture above.
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Old 08-04-2012, 08:33 AM   #317
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Quote:
Originally Posted by benthic View Post






Spencer
I think this applies:
Quote:
Originally Posted by bmweuro
If there is carbon completely covering the outside edge of the piston then there is a really good chance your compression is good. If the outer edge is clean then you have oil bypassing the rings.
Though earlier compression and leakdown tests showed "ok" results, I'm thinking this would be a good time for new rings and a freshly honed cylinder.

34 year old moto with 30,000 showing on a non-functioning odometer... what have you got to lose?
ring job = better compression and less oil burning... think of the environment
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Old 08-04-2012, 08:43 AM   #318
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+1. My first thought, too, seeing that piston crown.

Valves? Valve guides? (u.s.w.)...
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Old 08-04-2012, 08:46 AM   #319
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PS-- ever seen a project Snowball like this one?
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Old 08-04-2012, 10:01 AM   #320
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PS-- ever seen a project Snowball like this one?
All the time. Most projects snowball. Can't get away from it.

I remember once I was a gonna change the push rod tube rubbers......
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Old 08-04-2012, 11:39 AM   #321
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Flooding carb or bad ring seal. Maybe both?
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Old 08-06-2012, 10:40 AM   #322
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that's SOME pig!

Happy Monday everyone!

productive weekend for me (lot's o' pics today)! First - big Mike V. had some time, and the inclination, to help me with my wheel bearings!

Here we are cooking the rear hub to get the old races out. you can see we had a barbeque going with the old grease catching on fire:)



then clean-up, and bearing stack assembly for the freezer...



we heated the hub back up, pulled the stack out of the freezer and that sucker just dropped right in! I tool a video, but didn't upload it yet... it was pretty slick. you can see the white frost on the shaft sticking out of the hub here:



Then on to adjustment and testing. There was much measuring of wedding bands, torquing of axles and pull testing! end result SPOT ON wheel bearings:) THANKS MIKE!



Similar procedure for the front, but we just used a hand held torch instead since the races are captured independently on each side.



finished up the front wheel bearings and I was all excited to mount some tires. EPIC FAIL. I punctured 2 tubes trying to get the front tire installed. I was pretty irritated and gave up and took the wheels to a local shop for mounting of the tires. oh well. but i really don't see how an average person is expected to change a tire on the side of the road with the stock 4" irons when I couldn't do it with a friend there to help me in a controlled environment. frakking tires.

anyway, got the wheels home and started working on the bike again:) Finished the swing arm bearings, installed the brake shoes, and got the swing arm installed.



then I forgot to take pictures for a few hours;) Here is the frame with wheels! Renner had stopped by right after I got the rear tire on and helped me prop up the frame but wisely didn't stick around for the front wheel install;)



I felt ambitious and glued some rubber to the feet of the center stand and kickstand:



Then I proceeded to almost drop the bike off the lift installing the centerstand. luckily i was right next to it and caught it with my head. Once on the stand, and SECURED to the lift, i started fiddling! I had rebuilt the calipers and MC earlier in the day and wanted to mock them up:



I also started installing the wire harness:)



It's starting to look like a bike again!



Had to put the tank on. I think the bike looks awesome:)



There was some more engine work too. I pulled off the other jug (getting the other cylinder off was very difficult. I need some rubber mallet massaging)



the other piston looked as bad as the first. this is the first piston after some ultrasonic cleaning next to the raw second piston.



this is what both pistons look like after plenty of UCing and some elbow grease.



the valve assemblies are soaking as i type this. I'll see how they clean up this evening:)



the plan is to get the cylinders honed locally, and get some new rings. sigh. it never ends;) I'm not sure what else I'll get done this week, and i'm out of town this weekend... But i think i'm still on schedule for completion at the end of the month (or at least a form of completion;) ).

Hope everyone had a great weekend!
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Old 08-06-2012, 11:08 AM   #323
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So when are the heads coming apart to inspect the valves?
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Old 08-06-2012, 12:03 PM   #324
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Quote:
Originally Posted by Bill Harris View Post
So when are the heads coming apart to inspect the valves?
soon i think. Renner has offered to help me with that, but i think we're both pretty busy this week.
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Old 08-06-2012, 02:34 PM   #325
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It'll be easier to clean, and it makes sense to look as long as you're this far into the engine. Unless you have bad valve face recession or real sloppy valve guides, you can clean it, lap 'em in and reassemble with little time and $$. If you do have slight wear, note that and schedule repair for "in a couple of years".

And take a peek at the rocker arm needle bearings and rocker shafts.
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Old 08-07-2012, 12:46 PM   #326
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Hey guys, just back from Floyd's Automotive Machine Service - my cylinders have been honed! he told me that because of the heavier wear at the top of the cylinder that honing is unable to smooth out, I'm about 90% right now. But he said he didn't think i'd see a difference in performance if he bored them out, but I'd definitely see a difference in price after i bought new pistons;) good guy, he was pretty patient with me too, because of course I had questions;)

best part - $20. i couldn't have bought a ball hone for that, and I had a professional take a look:)

So now I have to order the correct size rings. I'm still not sure how to determine the right size rings... but he told me as long as I get the standard size rings that go with these pistons that I shouldn't have to gap the rings (as the cylinder is minutely larger). my pistons have 84 775 on them - so which rings do i want?...

Thanks!
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Old 08-07-2012, 02:58 PM   #327
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OK, so put jugs and slugs on the to-do list for 2025. I know that my piston clearance is at the upper end of spec and in 100K I'll need new pistons (as in pi$ton$). The way to tell is to mike (measure w/ micrometer) the pistons and cylinders. At worst, there'll be some piston slap (esp on a cold engine), but nothing profound. DO check the ring gaps-- they are usually good, but not 100.000% always. The ring size is determined by the cylinder ID, and yours will likely take whatever is standard for an R80.
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Old 08-07-2012, 09:57 PM   #328
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hi all!

I took a few videos recently if anyone is interested:

big Mike V. and the bearing stack! We heated the hub and froze the stack and...



my visit to Floyd's today and the honing. simple and quick with the right equipment:



after the honing, he took a ball hone to the cylinders



lastly, i mocked up a rear fender tonight out of aluminum.


the stock seat almost works with it, but that wasn't really the intent... i will try to fiberglass a seat pan soon...
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Old 08-08-2012, 05:06 AM   #329
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love the vids!
i wish people would post more of these kinds of things as computer nerds like me have no idea what any of these processes actually are that you schooled peoples talk about so freely with your machine shops in your garages, haha.
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Old 08-08-2012, 05:48 AM   #330
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It's a lucky man who has a motorcycle lift. I am so envious.... I wish I had room for one.
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