72HK1 For CJ

They should have the 8 on them,someone must have changed em. The bolts that hold the skidplate are a little longer than the two that hold the pegs only.
 
racerx said:
Extricating the valves may take more force but, no magic by any means. Odds are good that the guides will clean-up, too. You need new valves, not a big deal. However, I'd take a close look at the rest of the valvetrain...rockers, cam, springs; rust and/or scoring on the contact surfaces of any of those parts means they're bracelet charms (except for the cam, it's big enough to be a paperweight).

OTOH, I think you're a bit optimistic about the cylinder. If the piston was binding due to rust & oxidation, it'll take at least a first OS cut to reach uniformly clean, solid, metal. And the rings are now scored, iron oxide is a tough abrasive. Don't be surprised if it needs to be taken out to second OS, due to a couple of deep pits. Rust pitting is anything but predictable. Since there was enough rust to seize the valves, the cylinder is unlikely to have fared any better...unless the piston was at TDC. The rust sez that it wasn't.

As for cleaning the case halves, there are only two options if you wish to preserve what remains of the as-cast surface...chemical cleaning and soft media blasting. Sodium hydroxide (caustic soda), as found in oven cleaner, can do a pretty good job. It's a messy task. You'll want to remove the tranny bearings and use a nylon bristle scrub brush. Work quickly & rinse thoroughly and you should get a nice, bright, surface with most of what remains of the original surface largely left intact.Soft media blasting is quicker & cleaner but, the process is more specialized & riskier. Both processes have their pluses & minuses. Neither can restore damaged surfaces. Any pitting/oxidation etching will remain, with either process. Once the original surface is gone, it's gone, regardless of the cause..."can't make chicken salad from chickens**t". NaOH tends to leave behind a shinier-than-original surface but is accessible to the average DIYer. Soft media blasting can be gentler on the metal, depending on operator skill, but is harder to come by and costs more.
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The rockers and cam, ect., still look brand new. The cylinder may need to be bored over. The Wd40 freed it up pretty quickly. I did take it to the carwash and got most of the junk off of it and it looks alot better. I found some oven cleaner, but when I got it home, I then read the warnings and it said not to use on aluminum. I guess it may etch it.

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OLD CT said:
They should have the 8 on them,someone must have changed em. The bolts that hold the skidplate are a little longer than the two that hold the pegs only.
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I don't know why someone would have changed them, unless they swapped them out for some reason. They don't look like typical generic ones, but are completely blank and all the same size. I thought as you do, thinking the fronts should have been longer. The pegs fold up and stay like they've never been used. They move very freely though and don't feel rough. I compared the peg assembly with the original to my K1 and they look identical, but the k1 original pegs do not feel spring loaded.
 
Check the label to see if sodium hydroxide is the main ingredient. Environmental regs keep changing and the formula may be different. If it's the same as always, then that's what you want. The key is working quickly, giving it just enough time to do a light chemical peel. That's what gets rid of the staining and brightens the surface...without altering the texture.

Sounds to me like the motor may have remained dry inside, other than the combustion chamber. However, two stuck valves has me wondering if it's possible that the moisture could have remained isolated to the top end. You should have a quick, partial, answer to that question when you pull the clutch cover. If the primary gear, shift star, detent assembly, clutch release mech., etc are all clean & 100% rust free, you're probably good-to-go. If not, do yourself a flavor and split the cases. Usually, there's enough oil film to keep the rust away...but...given enough time, oil film goes away. Inspect & remove doubt.

Peg detent action is dependent on condition. The K1 uses a plate detent, instead of the ball/socket setup. The plates wear out and are not available as service items.

As for the unmarked bolts, dunno. I'm inclined to agree with Pat. That said, however, I've seen a lot of bikes with 4 unmarked bolts. What makes this a head-scratcher is that, while many have clearly been replacements, others have had 2 pairs of stock-length bolts, with the longer ones in the correct locations. Brake arm & tail light bolts are sometimes unmarked. Taken together, it's enough to make one go "hmmmmmmmm?":39:
 
Thanks Bob. It does say Sodium Hydroxide. How long do I leave it on? When taking it off, do I just wipe it off or do I wash it off? I experimented and sprayed an old beat up, badly stained hub and left it overnight. It oxidized the rest of the life out of it.LOL.

When I drained the oil, it looked normal and had no sign of moisture or contamination. The dipstick was also squeaky clean. I also didn't find any hint of oil leaks anywhere.
 
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Get a soft bristle brush, or rag & wear rubber gloves, and scrub just until the metal turns bright & clean...then rinse, rinse & rinse again. This stuff works quickly, in realtime. You've already seen what happens when left on (waaaaaay) too long. That can include residue. The saving grace is that water alone can remove all traces, though I'd wipe the part dry, and the process can be repeated.
 
I experimented on the valve cover and I must have got it wrong. It cleaned it, but it tarnished it leaving it a darker color. I'm not good at this, so I need to try something else. Bug and tar remover?
 
I always had good results scrubbing aluminum castings for a few seconds, then rinsing. However, the 2014 EasyOff formula might be different. If it is, then all bets are off. The stuff I've been using is really old. What have you got to lose with the wheel cleaner? $5 is a small bet.

BTW, concentrated PineSol does a pretty nice job on aluminum but, it only seems to work well when heated and needs a long soak time. You'd have to split the cases & remove the tranny bearings first and it sounds to me like you're trying to avoid splitting the cases.
 
Yes I am.lol. For right now all I want to do is just get the thing really clean, then remove the clutch cover, and inspect/clean the spinner/screen. Kirrby is sending me a flywheel/stator combo, another head assembly, and other stuff. I'd like to have the bottom end ready for those, if possible. I will then move on to the body and chassis clean up. Discovered that mice have wreaked havoc on the wiring harness. Hopefully they didn't screw with the switch. Most of the damage I found is around the batt box area. I haven't looked in the headlight bucket yet. I did alot of scrapping with my fingernails to get the drops of melted plastic off of the paint. That took a few hours, but came out pretty good and didn't hurt the decals. I'm also finding assembly paint markings here and there, for instance, the cylinder jug has a white small paint marking on the bottom, just behind the plug wire holder. A yellow and green on the bottom of the head. A white mark underneath the speedo holder. First time I've seen this stuff in person. I've been soaking the clutch cable for a few days to see if it will free up. Fortunately, all the cable sheaths are still in excellent condition. The front brake assembly is locked up and won't brake. I think the pivot is just stuck and needs some grease. The outside of the hub itself still looks decent. The original Nitto has one dryrot crack from sitting flat(I was hoping to save it:2:), but doesn't seperate when inflated.
 
I've used Dawn Ultra Power Dissolver (original use for pots & pans) on model airplane engines and it got rid of baked-on crud from the oil in the fuel. Left the aluminum looking pretty good. The bad news is that they have discontinued that product and replaced it with a more benign version that doesn't do the job of the original. Must be another EPA thing.

Anyway, when I found out they discontinued it, I bought four bottles on Ebay. You may still be able to find some. I don't know if it will do the job on your project.

One other thing modelers do is place aluminum engine parts in green antifreeze in a crockpot overnight. I've seen the results and it cleans very well.

Do not reuse the crockpot for food. Once you place antifreeze in it, it's done cooking food.

Bob
 
Thanks. I was thinking lastnight that Dawn might work. Didn't know about the other stuff. Does the older bottle(pre EPA good stuff) look different than the new. I checked ebay and saw different ones. Please post a pic of it.

To bad, but I don't have a crockpot that I can sacrifice.lol. I might be able to find one at a garage sale or Good Will.
 
Finally got time to read ure thread...


Congrats CJ! You scored an original RR HK1 with low mileage. You deserve it, can't wait to see her on the road!:rockon:
 
Adam-NLV said:
Finally got time to read ure thread...


Congrats CJ! You scored an original RR HK1 with low mileage. You deserve it, can't wait to see her on the road!:rockon:
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Thanks Adam. I can't wait to see it on the road either.lol. It's going to be a little while.
 
I blasted the cylinder jug today and, sure enough, there is a slight pitting at the front near the combustion chamber. I looked on the Honda parts finder and they don't make the .025 rings or piston anymore up to the .075:(.

Before blasting, I took a pic of the paint mark on the bottom of the jug for anyone that wants to know. I kinda hated blasting it off, but had too. The top looked pretty drab.

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You don't really have to go with OEM. If anything, I prefer the newer kits with a 3-piece oil ring. If you want NOS, you know how to get in touch.

That said, however, I'd take that cylinder to the shop that's going to handle the overbore & honing. The pitting might be deeper than 0.25mm.
 
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