FJR Engine Forensic Analysis

[raYzerman]

If you don't know which piston goes in which hole and the original orientations, your SOL in my opinion. Hopefully all the parts got marked somehow. Otherwise, you would need minimum new rings, and a way to hone the ceramic coated bores.

Ahem, biting my tongue... the Award-Winning guy put nary a mark on anything, pistons have their con rod bearings/rings intact, engine case has crankshaft in it with that half of the bearing underneath it, other engine case had 3 of the other halves, and one fell out.... I know where they go. You are quite correct that each piston skirt and ring set would have worn in to its cylinder and taking it apart without marking anything was pretty dumb. I would not put it together without new rings, bearing halves (crank & con rod bearings), gaskets, etc. I do not believe one needs new pistons but once cleaned, I'll look closer.

As for the bores, Nikasil plating is thin but hard, newer tech can go 0.002", older was around 0.004", the extremely thin nickel surface part of it wears off quick, so "break-in" is quick. I hesitate to call it break-in except for microscopic "smoothing", I hesitate to even call it polishing (we can't compare this to cast iron bores that actually wear in/bed in). Honing would be too harsh, would ruin it. The original cross-hatching is still there, a testament to its hardness. So here's the dilemma, with new rings, will they "bed in", and perhaps the answer is yes, they are softer than the ceramic (I think). Cost-wise, new Nikasil plating is ~C$1000. New set of engine cases are U$1100, say C$1400+ (Partzilla). Bearings are ~U$100, gaskets ~U$60, new valve seals U$100, assuming one can get away with just a cleanup, which I think is possible.

[John d]

The original cross hatching was always somewhat visible when I rebuilt Norton Commando engines. I really don't know anything about modern plated cylinders, but there is a lot you can Google about it. If it was my bike, I'd take the cylinders over to a professional engine builder for their opinion as to whether or not they think those bores could be cleaned up for reuse, before I spent any more money.

Best of luck there Ray.

[raYzerman]

Rather than wait any longer, I inspected soaking pistons, took a popsickle stick to scrape some carbon off. Surprisingly, the carbon wasn't hard, and I could scrape most of it off except what was plated on there (thin). Then I took a toothbrush on one half (not effective), then I used a brass brush on the same half (the upper half in the photo). Today, I used the toothbrush and toluene. That will do it. I did not spend more than a minute on each one, so it ain't that bad. So in the photo, if from left to right they are numbered 1-2-3-4, we have 1=raw unsoaked, 2=Simple Green, 3=Techron, 4=Ring Free. But at this point I can clean them all up with brush and Toluene pretty much. I would soak the unsoaked one in Simple Green by the looks of it. We'll discuss the solvents later. I have looked up the MSDS to see what they are made of.

[bungie4]

If you don't know which piston goes in which hole and the original orientations, your SOL in my opinion. Hopefully all the parts got marked somehow. Otherwise, you would need minimum new rings, and a way to hone the ceramic coated bores.

I had the same thought.

[bungie4]

Ray (Alan)..

Part of my job is making MSDS sheets available to workers (even thousands of feet underground with no WIFI), I don't manage the actual compliance, that is somebody else's nightmare. You might find this site useful https://www.mysds.ca/

[raYzerman]

Update, I was away a few days and left the Simple Green one soaking. Today, the remainder of the carbon came off quite readily, wiped it with Toluene which didn't do or need to do that much, then scuffed it with some green Scotchbrite (I didn't need to). Spent maybe two minutes on it, and this is the result. Soaking the others in Simple Green, seems to work the best. I should mention right from the start, there did not appear to be any carbon in the ring grooves and the rings rotated freely.



A comment on the solvents:
Techron - Majority is Naptha, with very small amounts of Stoddard Solvent (mineral spirits) and Benzene.
Ring Free Plus - Base oils mixture 70-90% (it is very oily), 5-15% Naptha, plus very small amounts of Benzene, and 3 proprietary chemicals. The carbon deposits were oily, but not sure if they soaked them at the dealer.
By comparison, Seafoam is mostly Naptha and isopropanol. None of these dissolve carbon. It would only come off by scraping.
Simple Green is 85% water, some alcohol, Sodium Citrate, Sodium Carbonate, Citric Acid and surfactants. It works, not so sure I'd put it in my gas tank.

[Full House]

Ray, How is that reassembly going? If it was decent riding weather I would venture to the far north and lend a hand!

[raYzerman]

Yes, it's been a while, lots of stuff going on behind the scenes. This thread is for "what went wrong" and today we can probably wrap that up. I got the cylinder head on the bench (see pics in first post) and poured fuel into the intake and exhaust ports covering the valves in liquid. The idea is to find out which valves leaked and caused the low compression readings. I have no opportunity to talk to the mechanic... I'll just say, no valves leaked. However, things were oilier than I expected from just pulling the head off a running engine, there was carbon but it should have been a lot drier. I expect the mechanic may have dumped on some RingFree (it is oily) or oil to either soak through the carbon or preserve things for a later time. Don't know. All I can really conclude is, the engine needed decarbonizing as it was ridden like grandpa, likely had a valve or two leaking, and hopefully his compression tester was accurate enough. There really isn't anything obviously wrong with this engine that I can see. Rings weren't gummy and stuck, unfortunately not enough information available from the mechanic. So, not going to worry about it, time to get on with the project and I will update the other thread.

Edit - added..... I did clean up the carbon from the valves, very simply, scraped off most of the big stuff with a popsickle stick, squirted on some Simple Green (didn't wait very long) and proceeded to use a wire brush and sharp popsickle stick. It didn't take all that long to get most of it off, and Simple Green works the best. Finished up with another squirt or two with Simple Green and a round wire brass brush chucked into my drill. We're good to go.

[wheatonFJR]

I see that this mechanics work requires a lot of popsicles.

I'm learning.

[raYzerman]

I see that this mechanics work requires a lot of popsicles.

I'm learning.

Only two so far... I cheated and used a plastic scraper too... trying not to gouge the aluminum.

[dcarver]

Ring Free Plus - Base oils mixture 70-90% (it is very oily), 5-15% Naptha, plus very small amounts of Benzene, and 3 proprietary chemicals.

That's interesting to me. Does the MDS have cautionary measures for these 3?

[Bust]

Yep. Been there done that. Carbon buildup under valve seat.
https://candybuttorg.ipage.com/pix/moto ... Zy8/18.jpg
https://candybuttorg.ipage.com/cba/node/221

Used to be a pretty fart smeller on the other board who worked as 4th level GM troubleshooting doode. He eloquently wrote about what wonderful things with ring expansion, fuel/air turbulence, and carbon minimization when running in the 'fun' zone. Wish I could recall his handle.

Good work Ray!

Jestal Don

[raYzerman]

Ring Free Plus - Base oils mixture 70-90% (it is very oily), 5-15% Naptha, plus very small amounts of Benzene, and 3 proprietary chemicals.

That's interesting to me. Does the MDS have cautionary measures for these 3?

It says if swallowed, stick yer finger down your throat and puke. Wait, you did that in your teens, yes?
My personal advice, don't mix with yer good alcohol by accident.

[raYzerman]

Just going to add, valve stems were all clean as were exhaust valve heads. Throttle bodies had a sooty coating but were not grunged up.... my guess is grandpa rider never went much over 25% throttle, never hit the power band to get the carbon out/minimize it. As for the chemicals, seems most rely on the naptha component, put a couple other things in there to make it their unique product, although I still don't get the oil content in the RingFree..... use what you like is the bottom line, I'll stick to Seafoam as it will take care of any water in the fuel if you ever run into that issue.

[bill lumberg]

So we should get it over 5k every now and then, or flirt with redline every now and then, in order to keep things clean? Serious question, but looking for more excuses as well....

[Hppants]

Works for me..... JSNS

[raYzerman]

You can flirt with red line, but 7k is OK... in third gear that's humming. I wouldn't do it in first, and when you shift to second, be sure to engage that second gear fully before twisting the wrist too hard. At 5 k, the engine is just getting into its happy place. However you do it, do it safely and comfortably.

[wheatonFJR]

You can flirt with red line, but 7k is OK... in third gear that's humming. I wouldn't do it in first, and when you shift to second, be sure to engage that second gear fully before twisting the wrist too hard. At 5 k, the engine is just getting into its happy place. However you do it, do it safely and comfortably.

Screw that. If flames aren't shooting out of your headers, yer doin it wrong.

[bill lumberg]

America.