Unusual damage...

[Larzfromarz]

Hey guys, I just thought I'd share a little experience with my 1966 CA160 though it applies across the board. I got my bike earlier this year and worked on getting her running after 20 plus years of sitting in somebodies basement. Since the bike was in great condition I choose to preserve rather than restore.
Upon getting the bike running I noticed that the right cylinder smoked a bit. I started to treat with some Marvel in the oil and gas thinking I might have a stuck ring which wouldn't be too uncommon for a bike that has been sitting.
I figured on treating and running the bike in hope of loosening the rings. While I don't actually ride here in St.Pete to much (you are car magnet in central Florida) I was putting enough time on her to sort this out, or so I thought.
Anyway since part of my mission is "rehoming" bikes to folks needing a vintage experience, the opportunity came up to place this bike in a good home. Since I don't like passing problems on to other folks, I decided to pull the top end and get a look at the rings and determine if I had stuck or broken rings. Turns out that the later was the case and now I suspect the reason for parking the bike in the first place. Both plugs looked real good and the head and piston ( in the bore) looked normal. The bike ran well and seemed to have good compression (though I never did a comp check).

[Larzfromarz]

Up until this point I was fairly happy with how things had gone. The cylinders came off with no trouble and I found the little culprit causing my little red Honda to become and Indian sending smoke signals out the right pipe.The first fuzzy pic is the piston still mounted the next is the damage to the bore, the third the damage to the piston and finally the broken oil ring. Interestingly the top two rings were intact and I'd suspect that when doing a comp check at TDC might NOT have revealed the damage to the cylinder. Its hard to say at this point. The sad part is the damage to the bore. Upon measuring it would need at least the first if not the second overbore. Bummer. I called Terry at Western Hills and they can get everything to do the job and had all in stock except new wrist pins, which they could get. Without machine work we were at nearly $400. More bummer.

[Larzfromarz]

Fortunately, I happen to have a "spare" CA160 waiting it's turn in the shop. I knew this motor was "tight" and not in a good way, but thought what do I have to loose by tearing the top end down and taking a look. One commercial later I had a new bike- wait this isn't reality TV. Hours later and after struggling to get the pistons far enough down in the bore, I got the wrist pins out and removed the cylinder assembly. I could now pop the most stuck piston out of the top of the bore fairly easily, which occurred with no surprises. Initial inspection reveals nice cylinders on the factory bore and within specs and two undamaged pistons.
Funny enough though the stickiest of the two pistons did have stuck compression and second rings and remains stuck now (tho soaking in carb cleaner). In the end though I have two nice pistons and one good cylinder set all in standard bore. Don't get me wrong guys I have no trouble in going oversized but since this is less than 5000 mile bike and the object is preservation, a std bore means something to me wrt to originality.
The first pic has the original to the bike cylinder on the left and the replacement on the right. Bead blasted and cleaned ready for honing. The third pic is part way through cleaning the pistons. I wanted to show the next owner the reconditioning process and I finished the blasting.
Note for those concerned: I do bead blast, then wash with mineral spirits, then run through the dishwasher ( when wifey isn't home), wash with clean hot water and usually a wipe down with lacquer thinner before painting or clear coating. Wash Wash Wash.

[Larzfromarz]

I next took to disassembling the head. The cam looks wonderful and the lobes and bearings will get a quick polish just to brighten them up. I removed all pieces and blasted the valves, compression chamber, exhaust ports and the rest of the head and labeled everything as to location. I'll get some lapping compound and "lightly" lap the valves.
Ultimately there could have been a burnt valve causing the initial problem but the chances of that were lower from the start so I was pleased at the condition of the valve set. I'll post pics of the reassembly once the rings and gaskets get here.
Just so you know a ring set runs about $110 from WHH but you can find cheaper on Ebay.
In this case the job can be shaved by using in spec "serviceable" parts.The job went from nearly $500 to less than $100 and (most importantly) I feel will meet my expectations for a proper repair and give good service to the customer. Now what it does mean is that I have now shifted the overbore job to a later project but can now spread those expenses out over a longer period of time so I am happy with that as well.

[Larzfromarz]

Rings arrived while I was away so we (I) can start the reassembly soon. Amazing but understandable that standard ring sizes are HARD to come by.

[Larzfromarz]

Finally got around to finishing the CA160 top end rebuild. All in all a pretty easy job. Made the usual mistakes, lost the cam chain tensioner a couple of times and learned how to "fish" cam chains. On the other hand I am certain about the timing and valve adjustments so am looking towards a nice start up.
I replaced the case fasteners with button head ss where possible, polished what I could, and painted the side covers. New rings on serviceable parts, std bore, lapped the valves ever so slightly, painted the cylinder and head, side covers and valve cover. Removed surface oxidation on the engine case and HI temp clear coated most everything. I probably should have replaced the clutch discs but I'm anxious to get it back together on the bike and the clutch project is an easy afternoon project.
Everybody likes engine pictures, right?

[Spokes]

Very Nice. You will be very pleased with the performance of the CA160. This engine is much stronger than the CA95.

Don't be to concerned with using the old clutch discs. I have reused the discs in three of my 160's without any issue.

[Larzfromarz]

Thanks Chip, the bike ran great before it just smoked a bit from the right cylinder. I was selling the bike but wanted it to be right, and the deal fell through. So now my Superhawk is near ready for the street hopefully I can get the wife interested in riding the CA. It 's a decent starter bike for her. Weather is getting better even here in FLA so the season is right to enjoy the bikes a little. I'll post video of the fire up on the CA next week.

[Larzfromarz]

Well here we are. Are some trial and tribulation with the cam chain we got the engine installed and running this morning. I'm very happy, it sounds good, doesn't smoke anymore from the right side. Just need to fiddle with the carb a bit and get it timed for better starting. All in all a great learning experience.

[Larzfromarz]

The bike is running well and we have miles on it now. So far only a small leak at the drain bolt. Starts on the first or second kick. Very pleased.

[Spokes]

Yes, the CA160 is really a nice bike. A teflon washer on the drain bolt will seal nicely. Congrats!