Hello from San Diego

Griff · #1 01-22-2010, 03:32 PM

Just found this forum, good timing too.

I just picked up a real clean 1966 CA95 (Blue with OEM winker kit, nice white Buco bags with keys, 4,000 miles, org. tires, etc...) at a local yard sale.

After new plugs, batt., air filter and oil change it started, ran, drove well, and all the electrical worked A+, but it smokes pretty badly and fouls plugs quickly.

I plan to do a motor refresh on it. I assume a ring/piston kit first? I also found some OEM ring sleeve kits on Ebay, is this recommended to do too, or bore it to the first over? Also are there valve seals on these?

Looking forward to tap some of your knowledge and share my experiences.

Spokes · #2 01-22-2010, 05:18 PM

Nice find for sure.

Before teardown, check that the crankcase is not overfilled with oil. There is a volume marking in the right top of the crankcase that indicates .9 Liters (just a tad under a quart)30W over 60F 20W under 60F. When you drain the oil on these engines you typically drain out about .8 Liters or so. If you put in a full .9 Liters after a change the crackcase will be overfull, and you will get some oil burning.

Also, there is a crankcase vent tube that goes from the top of the engine to a port next to the carb. Start the engine and pull that rubber tube off and you should feel air being pumped out. If not, the crankcase is building pressure, which will cause oil burning.

Mechanically, worn valve guides, worn valve seats and piston rings are the reasons for oil burning. If you can find a shop to press out the sleeves and install new standard pistons and rings, do it. Have a shop determine if the cylinder needs to be bored. If so, order pistons .25-.50-.75 or 1.0 over. (I had a real bad cylinder bored to match a .75 over piston, no problems)

There are no valve guide seals.

Buy new valves and guides and have them installed with new seats cut into the head. All of this sounds expensive, but it is not too bad. But find a good small engine rebuild shop to do the work. I have one here in Kentucky that did a great job and it ran me about $200.00 and I supplied the parts.

Smithers · #3 01-22-2010, 06:37 PM

Welcome! Nice find. I hope you didn't fire if up with the old oil in it. Gotta take care of that crank with clean oil. Everything else is rebuildable. :-) I hope you can find a good shop to help out. You just need to have someone measure and determine if you can just replace the rings or if you really have to go a step up in piston size. The smokin and plug fouling is what my blue one was doing when I first got it and I knew it when I bought it. But that's basically why I did all the work on it in the first place. You got it made here with all the knowledge and our work you can follow. Just put everything in zip-lock bags when you take it apart and make sure your impact driver bits are nice and sharp so you can take out those screws without marring up the caps.

Step 1: check that crankcase is venting properly if not go to step 2 :]
Step 2: disassemble engine / take cylinder head to reputable machinist to have measured.

I wouldn't order anything until you know exactly what needs to be done to cylinder. Mine was really screwed up and I had to order ANOTHER set of pistons and rings.

Griff · #4 01-23-2010, 09:54 AM

Thanks guys, it may be overfilled by a tenth liter or so, I'll check it and the crankcase breather operation today.

Have you guys ever done a leakdown or compression test on these motors to check out the internal condition? If so, what kind of numbers are you seeing for an average healthy motor?

Thanks for the help!

Griff

Spokes · #5 01-23-2010, 12:44 PM

Frankly I never owned the right guage to check the compression correctly on the CA95 I rebuilt. But, with an old compression guage, the type used on old V8's by holding the guage tight into the cylinder hole, I got 105lbs after 5or six rotations using the electric starter. I think I did not get an exact reading. The bike ran fine. The manual, which you can download a copy from this forum, says the CA95 should get 130lbs.

From the "old days" you would take a compression reading, then add some oil to the cylinder (few ml's just to coat the top of the piston). If your compression increased, your rings were worn, if not, your valves may be bad or not seated.

Change the oil first. 30wt non detergert oil is best, I ran 30wt diesel in mine.
Measure the oil that has drained out and compensate the fill against the suggested capacity (.9L) While your at it, look at the magnetic post in your oil drain plug. Oily powder like "stuff" is common, slivers could mean trouble, big slivers could mean bearing failure imminate. Also look at the oil and check for a silver like ploom. You should not have too much. Don't be afraid to change your oil often.

By the way, you also have a centrifical filter(sp) behind the right side cover. Remove the screws, pry the cover off..carefully. You will see a plate with 4 screws, remove the screws and pop the top off. Inside you will see sludge. Hope it is not plugged, remove the sludge and reassemble. This step is done once in a while and not every oil change. And of course, check that crankcase vent tube and make sure it's pumping out air.

Griff · #6 01-25-2010, 04:56 PM

Ok, the crankcase breather is working just fine, and the oil is not (was not) overfilled.

I adjusted the valves today too, they were a bit off , but not too bad. I brought them into spec, no difference, still smoking.

So it looks like I'm tearing the motor down. I figure I'll do the whole thing since this thing is in such pristine condition, it'll be worth it.

I need a source for the new valves ( and while I can find the pistons/rings/sleeves on Ebay no problem, any recommendations on good sellers you guys have worked with would be great too).

Oh, here's a few pics of the bike with the Buco bags removed. Gotta toss on some new tires and tubes too, they're original...ouch..

Spokes · #7 01-25-2010, 05:34 PM

I bought valves, guides, pistons & rings from ebay as well. I did not buy sleeves, although I still think it is a good idea, but I can't say if it makes a difference overall. A good small engine machine shop can bore the cylinders and do the valve seat cut and fit the valves. But take the top end to the shop and get things measured first, you might just need rings. The engine is easy, I have one broken down now to every nut & bolt. In my case the valves look fine and I may just replace the rings, seals, gaskets and I am ready to reinstall when I get the frame( I am building one up from scratch)

I have a REAL WILD QUESTION! This may be far fetched, outragious, but I gotta ask......What color is the gas in the tank?

If someone overspiked the gas with STA-BIL the fuel would be RED, IF it was overspiked...it would give you that "burn oil exaust"....

If someone put a 2-Cycle oil mix in the tank, the fuel would be BLUE or GREEN. IF 2-cycle oil were in the fuel...it would give you that "burn oil exaust"...

Sometimes people add 2-cycle oil in the fuel of 4-cycle engine gas tanks thinking it will prevent rust (it might), or too much STA-BIL, because they think more is better.

Before teardown, drain the gas and refill with fresh. I know it sounds like a long shot, but it's worth looking at.

Griff · #8 01-25-2010, 05:57 PM

There was actually no gas in it when I got it (had been drained during its long term storage) Before I started anything I did a full oil flush and fresh gas/carb clean.

Also, I though it could have been a stuck ring, so I did the Marvel Mystery Oil thing to it, it didn't help at all (just made a ton of white smoke as it should) Once that burned away, the light blue smoke came back on cue.

I was wondering if running modern lead free gas could do this? Maybe some engine Restore or a gas additive might help?

Either way, I'd like to refresh this little guy the right way, the first time. On to Ebay!

Spokes · #9 01-25-2010, 07:12 PM

Yea, it was just a wild question. Engine additives are bandaids at best and if you use the wrong one you could make your clutch slip. I would do some pricing on ebay, but hold off on buying until you know what you need. Again, it might be just rings. The seal kits you get from Asia are actually incomplete. They sell you 7 when there is actually 8 not counting the seal at the kick start. You can still buy seals from Honda for your bike. Get a parts catalog and down load the manual from this forum. Gaskets are another thing. Check with the Honda dealer for the head gasket. I have the original and a direct replacement, some asian ebayers sell you crap. Make sure the head gasket has a metal ring around the cylinder openings at least. The other gaskets that the asian sources are thin, I have a place that copies them and cuts then to my liking (thicker)

If you buy new valves and guides, sometimes they don't fit. A good machine shop will ream them to fit.

The shop I used to do my bore to fit new pistons, install new valve guides and ream them to fit the new valves, then cut new seats in the head and reassemble the whole package is: Cornett Machine 1635 South Highway 27 Somerset, KY 42501 Call 606-678-5163 and ask for David. These guys specialize in small engine machining.

If you need any pics of the inside of the engine, I have one apart and clean.

Smithers · #10 01-25-2010, 10:14 PM

Nice blue! That thing is in awesome shape, impressive. About the additives I've always wanted to try the "Restore" bottles you can get anywhere including Wal-Mart. They make some very tempting claims. :P http://www.restoreusa.com/

Sam Green · #11 01-26-2010, 02:40 AM

Welcome Griff, a nice looking ride you have there.

I would have thought with just 4000 mile there would not be much wear in the bores, more like broken or stuck rings.
The motors are easy enough to work on and I doubt you'll need anything more than a set of rings. Forget the sleeves, they are only needed when the cylinder block has been bored 4 times.
Also with that mileage, I doubt there will be any wear in the valves or their guides.
The worst senario is that the motor has been run with little or no oil and is in need of a major refit, let's hope it's the former.
Good luck mate.

Sam.

hahnda · #12 01-26-2010, 06:59 AM

No need for new sleeves unless your bike has already been bored many times already. I can hook you up with a pair of pistons and rings depending on what size you need for $50 shipped. You will need to tear you engine down before you buy rings and pistons so you know what size to buy.

Then again none of that may even be needed. Try doing a leakdown test if you can. I have done one on a badly smoking CA95 and while I don't remeber the percentage of leakage it was substantial. You could feel the air coming out of the oil fill cap if you removed it. New pistons and rings and a lap to the valves helped tremendously. Something like 10% leakage still but many bikes run fine with numbers like that.

Smithers · #13 01-26-2010, 07:44 AM

Yeah you can't find out what the problem is until you tear it down. And it's such an easy little engine it's a piece of cake. Like the others said there's no way you would need to sleeve it at all. Just need to have a look inside and maybe clean up the cylinder walls, clean up the valve surfaces and put new rings in it. When I was 14 years old swapping Honda 70 motors into 50cc honda bikes we would just open them up, put new rings in them and that's it! No shop manual or anything... hell we didn't have any money or the internet! We didn't even buy new gaskets.

Slap em back together and just ride them forever and they would run all day on a tank of gas with the new rings.

Spokes · #14 01-26-2010, 09:41 AM

What I like about working on old engines and bikes is, it really comes down to what makes you happy. I guess I am the only one who suggested sleeving the cylinders, yea, most likely not needed, but a broken ring could gouge the cylinder walls pretty deep. But as everyone suggests, tear down the motor and see what you need and go from there.

If it makes you happy to replace every possible worn part, needed or not, again if it makes you happy..and money is not an issue, then, hey why not?

When I tear down these little engines, I go through great measures to put the engine back to pristine shape...you don't have to do such a job, but, I like to do it that way, it keeps me busy, makes me happy, ain't no big deal.

If I needed the bike right now, it would be another story. That said, I agree with all posts. Tear down the engine, hone the cylinder replace the rings, lap the valves, replace the gaskets assemble readjust the valve lash and ride.

Enjoy the repair or rebuild. To me it's all about the journey.

Griff · #15 01-26-2010, 11:46 AM

Thanks everyone, I'm gonna try and pull the motor tonight or tomorrow.

I'd love to be able to just to the hone/rings. I really bought this so I can ride around town / to the beach along side my wife who as a Vespa. My Ducati's aren't really a good around town riding companions for the Vespa!

Also, I just noticed the the Buco bag mounts don't line up perfectly to this bike (they might be for a Dream 305 or something) Before I go an fab something up, does anyone know a source who may have them already mocked up to buy?