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OK, I bought a barn bike today

Soda blaster

I'll have to check out a soda blaster (!)

OK - how do I determine the condition of the rod and main bearings and other engine internals like seals ? I notice many folk do not go into the bottom end. Is there some definitive method for checking that stuff ? Thanks in advance / RB
 
Bearings

rbleau,

You could use "Plastigage" on the rod bearings. If you're not familiar with it you can "Google" it and find out about it and how it's used. The main bearings should be in similar condition. I think the connecting rod bolts are "one time" use, someone correct me if I'm wrong. As for the seals, you should definately replace them. Even if they're sealing now, they will probably fail soon after you put the bike in service. Looking at your photos, it looks like the left side had open valves when the bike was taken out of service. Oh how I envy you, what a great project.

Ride Safe
MB
 
If there's no evidence of corrosion inside the case or of oil starvation, I would leave the bottom end alone. There's just no real reason to go deeper. You can look at the sludge in the bottom of the oil pan (some sludge is quite normal) to see if there might be a bearing problem. If not, just count your blessings and maybe go in as far as the timing chain on the front and the rear main seal on the back.

If there is a conrod bearing problem you would see it when you remove the conrod. In that case you will probably be in for a full-on engine rebuild.
 
Pete Speaks Up

Ok, I'm Pete that guy helping Ron with the barn Bike. I feel I must chime in, given my goofy picture is now spread through the forum.

Ron and I have been swapping stories, bikes, bar-b-que and good times talking and working on German steel since last year. The current barn bike project, corpse, is much fun to look at and work on.

The Kroil that was recommended has done wonders to this old barn beauty queen. We started to srtip down parts this weekend, and everything came off without trouble. The only item that needed a little extra work was the final drive drain plug, and even after Ron sprayed Kroil on that, she came off.

I'm posting a picture of the carb cleaning/rebuild I'm doing for Ron. I hope to post a more in depth slide show of how to re-install the enricher/choke correctly, since there is confusion on how to do this in other manuals.
 

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16MAR09 Update

Left side photo
 

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port (left) cylinder

View of port cyl
 

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Port piston

? What do you think of condition ?
 

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Pipe still stuck

headerstill stuck; cut muffler off. kroil in play.
 

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Starboard cyl

This one is in better shape
 

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Starboard piston

Looking better
 

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Starboard head

Worked on this one a bit today - Bar Sol
 

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People are going to tell you to replace the cylinders or at least bore them out.

Wipe the crap out, hone them, and report back.. before spending big bucks.
 
right head valve side

OK, well the last picture showed the better side, didn't it !

More work to do. But I am concerned about the sparklies in the oil pan - worst case the oil galleys and all bearings are infiltrated with metal bits, which implies a block boil total rebuild - is the bike WORTH THAT MUCH dough ? recall that nose to tail is all needing rebuild - bearings, calipers,...to rear bearings and drive.

need to mull this over a bit.
 

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Fun

Still looks like a fun project to me. As bad as those photos make things look, you really can't tell anything without cleaning things up and taking measurements. You need to engrave the parts, ie, right piston, right intake valve etc. Wire wheel the pistons and valves, run a dingleberry through the cylinders (with plenty of lubrication) and take the stuff to a good machine shop that knows air cooled engines along with your shop manual (for specs). Have them do the measurements and advise on condition. If you still want to verify bearings, do the plastigage. This will let you measure clearance and do a visual inspection of the crank (rod journals anyway). Is it worth a total resoration? It would be to me. A first year RS ( the photos look very original). Nothing like the feeling you get from riding and showing a bike you did yourself. I'm sending you a PM with my contact info. I would love to have a conversation with you about this project.

Ride Safe
MB
 
It depends on what you mean by worth it. If you rebuild everything from nose to tail with new parts then sell the bike, you will lose lots of money. What value do you attach to the satisfaction of getting the bike back on the road? How much will you ride it and for how many years? In the end, it is subjective and it is your time and money that is on the line.

I would plan on new rings and at least hone the cylinders and measure them for wear. I would probably rebore them. I would have the heads reworked. Others will have a different outlook. After reading the thread, I suspect you have a good idea of what you can live with and that you have fairly high expectations for the finished project.

I think you approaching it the right way. Go as far as you can without spending money, gather data and keep your options open. I hope you fix it, since I am enjoying your thread.:lurk
 
OK, well the last picture showed the better side, didn't it !

More work to do. But I am concerned about the sparklies in the oil pan - worst case the oil galleys and all bearings are infiltrated with metal bits, which implies a block boil total rebuild - is the bike WORTH THAT MUCH dough ? recall that nose to tail is all needing rebuild - bearings, calipers,...to rear bearings and drive.

need to mull this over a bit.

Well, this is not the best of news, but I wouldn't write off the project quite yet. Clearly, this will not be a quick turn around project. But, the bike is mostly there. If the bottom end is toast, then I would suggest getting a used bottom end. They are relatively inexpensive (compared to rebuilding the bottom end). You've got three other bikes to ride, so enjoy those while you get work on this one. As suggested, I would clean up the parts, and take them to a qualified expert.

This might be an odd temporary solution, but if you're dying to have an RS to ride, you can transplant the engine and transmission from one of your other bikes to the RS while you rebuild the RS's. Just trying to think outside the box here.

It's your time and money, so there's only so much "advice" we can give you here. Only you can decide how much time and money you're willing to spend on a project. My last suggestion is that try selling the bike as a project before parting out, if you decide not to put any more time and effort into the RS.
 
rbleau,

Clean the cylinders and inspect them before doing anything abrasive. Any scoring, or actual pitting from rust? If not, is there a ridge near the top, where the upper ring land stops moving at TDC?
Are they out of round, near the bottom of the stroke, where the most lateral force is exerted on the piston? There did not appear to be significant signs of blow-by on the pistons; 'though they both had some light scuffing, the port side looking worst. Seeing it near the rings, instead of the skirts, can be a sign of overheating or lack of oil (why is the question). Is that top ring on the port piston stuck?

Can you feel any play in the piston wrist pin to upper con rod relationship? How about the crank journal end of the rods? How does the crank rotate, now that you've eliminated the friction of the pistons in the bores? It's difficult to feel any slop in the main bearings, but sometimes you can see excess fore and aft play by actuating the clutch.

My top three thoughts on the source of your oil pan "sparklies" would be:
1. Those scuffed pistons (let's hope so, it's the easiest fix).
2. Bearings ('though I've not seen them leave fine "filings" like that before).
3. Your oil pump. Excessive end play can let the rotating gear chew into the aluminum housing behind it. Look for tell-tale circles when you remove the gear, if you do. This could be bad, or worse. Bad would be the pump couldn't keep up the pressure, the oil light flickered, and the bike was parked before worse harm was done. Worse would be the light wasn't noticed or paid attention too, and the bike wasn't parked until worse damage forced it to be.

You could keep disassembling until you find the source and fix it; but if those cylinders aren't bad after cleanup, I'd be tempted to put it all back together and try to start it. You may still have to take it apart again for a thorough overhaul, but you might be able to diagnose the problem first, and besides, what further harm could it do, if you're going to rebuild it anyway?
You never know, you might be pleasantly surprised.

If worst comes to worst, considering the condition of everything else, it would tempt me to pull the RS body work, repaint it, and put it on the /7. Then you can sell what's left of the RS to one of these die-hards who swears it's worth it, or part it out, or keep it around to tinker with and learn from over the course of several years, which would help keep the costs from stinging so hard all at once... and the safest place to store the bodywork may just be bolted to another bike.

Bob
 
Numerous good suggesions and tips - thanks !

Well, thanks to all - plenty to digest ! Lots of good ideas and suggestions !

Today I did cleaning on the left head and cylinder. Even with cleaning was very physically rough in the bore, so "we" - that means a qualified person, not I - honed the left bore. Initial reaction is that the rust went pretty deep. Some pics to follow.
 

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