witch city bit**

[jleonardmca]

Up north of boston(title needed an explanation), I discovered this one.

tires were flat(one was original?). the seller said the "carb needed some adjustment" and overall a little tlc.

dragged it to my driveway, fired up after some kicks and the electric. then....nothing.

so new battery, new plugs, new needle and jet in the carb, new tires, and finally life. but only when jumped.

took off the case for the kick start, put it back, now that works after a couple kicks when its cold.(it just slipped with no compression before) but i didn't do anything except change the oil.... anyway, took it for a drive and now I'm getting picky.

so the right boot for the spark only fires when it is slightly ajar. this is an easy fix BUT.....

the carb overflow is leaking a fair amount of gas. it has been. apparently there is a small brass tube in the bowl. regulates overflow. well supposed to be. there is nothing in there. its not listed in the parts or manual or anywhere. but it should be there! where do i get one??? anyone have a pic or measurements so i can make one??? my friend says this is never going to be a reliable ride, but i totally disagree. under 5k miles, feels great, sounds...ok -missing that sewing machine sound. but overall i think i got a good bike.

and the electric start...
button is missing. well, broken. no big deal there for now. once i put the new points on, if its still not starting on that, could it be the ground cable? going to experiment a little tomorrow.

so for now, ANY help about ANYTHING on this bike is appreciated. thanks in advance, i will be back here way too much in the future.

[Spokes]

I'm am a loss as to why the overflow tube would be missing. You may have to fab another or search for a scrap CA160 donor carb. I would charge the battery fully then try to start the engine. There is a chance thet your not generating any energy when the bike is running. Check the wiring from the engine to the harness for bad connections.

[jleonardmca]

so i got the brass tube to fit in for the overflow. anyone have the measurements for one? like how long is the brass overflow tube from where it connects to the bowl. and i think its sealed on top, but there must be a hole in the side? pics would be helpful.

[Spokes]

I just happen to have a dry loose carb from my CA160 build. The pic below should answer your question.
http://www.fourwheelforum.com/picture.php?albumid=57&pictureid=809

[jleonardmca]

awesome. got it. now it won't spark. condenser is fine. grounded. have new points on. gap is a little too big, but they still don't spark. the coil maybe? its under the seat right? saw a thread about replacing the wire? any other suggestions?

[Larzfromarz]

Check each wire for continuity. I had the wire from the condenser to the points bad. Check easy stuff first. You can measure the coil resistance (and continuity of the primary without removal if you trace the wires carefully.
Good luck-
L

[jleonardmca]

going in later today to do some work on this. got some wire for the coil, lets hope this is it... got a question kind of odd. what other bikes did honda make that are interchangeable with a CA160? looking more for the cosmetic stuff. like could i put a single seat from a ca95, and front forks off a CL, and maybe change out the headlight with CL or CB style? basically chop the whole front end off and put something else there.

i know this seems wrong. but i got the bike all hacked up (previous owner's home repairs) and i know i can get the other parts much more easily.

[Spokes]

Everything with the exception of the wiring harness and engine is interchangable with the CA95.

As far as interchanging the forks..maybe some other member might have the answer. I would guess that if you replaced the neck and used a matching fork assembly, that would work.

[jleonardmca]

anyone have a little step by step to repairing the coil? i found an old one on ebay but something tells me its not going to work. and is there another one that fits?????

[Larzfromarz]

Sorry but you don't repair coils. Simply replace them. Tests are easy if you have the specs. Problem is most folks don't have a good understanding of the multimeter they use and how to use it. The Clymer (or most manuals) for your vintage should have basic diagrams on the system and basic diagnostics.
What exchanges? If a 12 volt system your selection is greater, much less so with 6 volts. Most any of the same voltage two cylinder coils should work on a Ca160. Please stab me if I'm wrong- anybody else...?
Exactly why do you suspect your present coil and what have you done to test the coil? is the coil getting voltage? does the primary have continuity? is there no short between the primary and secondary, what is the resistance of the primary winding?If all else is know good-
The coil primary winding is good when you have battery voltage all of the way to the points (when open). When the points close the coil primary builds inductance and when the points open the magnetic field is collapsed into the secondary inducing a transformed voltage to go to the spark plug, creating a spark yada yada.
Coils are pretty simple and unless lots of heat has been applied tough to kill ( in theory). Practice may be something else. I wouldn't spend a fortune on a replacement until sure.
My 2 pesos and we know what thats worth-

[Spokes]

I have repaired 6 volt Honda CA160 & CA95 coils. By the way, the CA95 & CA160 use the same coil, so when you shop for one, check for both models.

1st thing to do is to look for waxy drips. If there is any sign of a wax like drip you can bet the coil is bad. Cooking the coil happens at random when you leave the ignition "on" and by chance the points are closed. How do I know? Been there done that.

Check both harness wires with an OHM meter. The coils that worked for me reads 1.5 to 3.0. I am not an electrical guy, but I like checking the coils.

Make sure the two wires that connect to the wire harness have good connections. I resolder mine if I suspect any issues. Clean them if their tight and good.

I also replace the spark plug wires and boots.

Buy 7mm snowmobile solid core spark plug wire, about 3 ft. I get mine on ebay. I always match the original lengh + 1" for good measure. Buy two new spark plug boots from www.hondaminitrail.com nice NGK's about $4 ea. You can get them from a cycle dealer for twice the price. OR you can get solid core 7mm spark plug wire with a molded spark plug boot from Advance Auto Parts or NAPA if your not concerned with what the boot looks like.

Carefully bend back the spark plug wire support bracket.

Where the spark plug wire enters the coil, you will see a hard sealant the same color as the coil. Chip the sealant away and pull out the spark plug wire out. Clean the coil and install the new spark plug wires and seat them deep into the pins at the base of the spark plug wire hole.

Seal the wire with a sealant that will cure. Bend back the wire support and Install the plug boots and your good to go.

I have done the above on 2 CA95's and 3 CA160's.

Having explained all of that. Make sure that the GREEN wire that exits the engine case and connects to your points is not grounding itself out. I have also seen this on one of my projects.

[jleonardmca]

yeah... but if i don't get any reading out of the coil....then what? everything is connected properly, and reading on the tests. i finally get to the coil, take the wires off, and the thing is dead. yeah it had some wax-like buildup like you said. so i found a replacement.... but i think the dude is giving me a bad coil... find out in a week... so now what? can i break this thing open? re wire it?

[Spokes]

If you found wax...then it's cooked. This happens when you leave the ignition "on" for some time when the bike is not running and by bad random luck the points are in the closed position.

I would still clean the next coil and throw new plug wires and caps on it, although the old wires may still work.

The next bad coil I get I am going to break it apart and check it out. I am a bit paranoid about the materials inside being made from mid "60's" material that may not be friendly. I have no proof, but gloves and a clean way to dispose of the remains would be in order.

As far as re-wiring it...I don't have a clue. Your may be the 1st to find out!

[Larzfromarz]

I hate to ask, but as a former technical support person I have to clarify some things in order to give better answers.-
Statements like- "but if i don't get any reading out of the coil" make me ask what "reading" are you specifically looking for, as opposed to "I measured the resistance of the primary coil and it was "x"".
Which tests have you actually done and are they done correctly? I only ask because I don't know your skills but I do know most folks have a little trouble with electricity. I've actually taught the subject to aircraft mechanics and can post a whole treatise on what to do and how to do it. I just don't like to push.

Basically you need to first understand what the coil is and how it does what it does. Its called a coil but is actually two coils called a transformer. If you think about it, it 'transforms' your 6 or 12 volts into 20,000 to 50,000 volts at the plug to make the spark. It does this through a process called 'inductance'. That's another lesson though.
The two coils consist of varnished wire coiled upon itself and wrapped many many times.The two coils, the primary coil and the secondary coil, must be electrically separated from each other in order for 'mutual inductance' to occur. Also the number of windings in each of the coils determines the amount or ratio of transformation of voltage (12vdc > 20kvdc). If the two coils are touching each other, or if the varnish wears from around a coil winding (due to Spokes' overheating reason) internally the coil can no longer set up the magnetic field (part of inductance) required to work. If this occurs the coil is "shorted". You'll find no magic, nothing special but varnished wire (and in older automotive coils some oil for cooling). This is why we test the coil by measuring the resistance of the length of wire used to make up the primary coil.
The Breaker points are simply the device that breaks or collapses the magnetic field that occurs in the primary coil and when that magnetic field collapses it 'induces' (thus induction) a stepped up voltage into the secondary coil which then continues on to the spark plug.
As Spokes points outs, leaving the key on and having the points closed just turns the coils into a heater and melts the insulating waxes and can get hot enough to melt the varnish on the internal coil wires eventually causing a shorted coil.
In general if the coil primary is good (measures 2-5 ohms of resistance) then proceed with further tests. This primary coil resistance test must be done with the coil assembly electrically isolated (unplugged from the rest of the circuit) but can be done while still on the bike or on the bench.
The attached diagram is from my Clymer's and the procedures they use are are not bad (though some manuals have bad data)- good to have on hand.
Sorry if this seems too academic, just trying to help.
Larz

[Spokes]

Great Info! Contributions from technical people like yourself and those who love the idea of saving old bikes/equipment makes this forum 2nd to none.

Thanks!

[jleonardmca]

yeah, i was testing the resistance. I'm learning this as i go with a friend of mine who actually knows what he is talking about. looking for the proper ohms, but got nothing. anyway. found a couple coils to replace it. hopefully this works. thanks for all the help so far, sorry i haven't been able to keep up on the forum lately.

[Larzfromarz]

Here is what I like to do regarding testing of ignition systems particularly if my main interest is getting the motor run when in an unknown condition.
Because the Hondas are pretty simple this method can be used to run an engine (providing mechanicals and carburation is handled).
Previously I provided a diagram of a simple ignition system from my Clymers manual for 125-200cc twins. These bikes mostly use a single coil with two hi-tension leads for the spark plugs. Larger displacement engines probably use two coils, each with its own breaker set and a single hi-tension lead for its assigned cylinder.
I have found it easy to assemble the makings of an "external or by-pass" ignition system to by-pass the system on the bike. At some point you'll have troubleshoot the electrical system but now you want to know if the bike will run. By eliminating several unknowns, we can increase our chances of a successful light off of our unknown engine.
Of course do some basics first- oil and gas, compression. Clean/adjusted carb(s) and know the engine can be kicked over. A freshly charged battery of the proper voltage is required. (A quick note: this battery doesn't have to have much amp capacity as we are only using it to provide the spark. For ease of transport I use a smaller battery for this external circuit if I can). Several feet of 16 or 18 AWG sized wire (gage), and automotive condenser from Napa, a single pole single throw toggle switch, a 10 amp fuse and holder, and a known good ignition coil. I have all of these as spare parts and assembled them in a useful way. Simple create the circuit as laid out in the diagram. Connect the battery negative to cycle frame, the 10 amp fuse and holder from the positive side of the battery to one side of the SPST toggle switch. From the other side of the toggle switch connect a wire to the positive terminal on the coil. Connect a wire from the negative terminal of the coil to connection at the breaker points. You WILL remove the existing wire for the time being. Now find a bolt or place where you ground the case of the new condenser ( a lead with alligator clips will do too). The location is not important as I also like to extend the wire that come from the condenser fro flexibility (See photo).
Once you completed this simple circuit you now have a complete ignition system using known good parts, doesn't require a key (big bonus) and should run the engine. The diagram works with single and early twins but can be modified to work with later bikes with two coils. Flip the switch and verify that you get battery voltage at the breaker points (best measure with points open). If so you can now kick the bike over. I like to do so first with both plugs out, my external ignition connected, and the known good spark plugs laying on the cylinders. You can look for spark. If so, install plugs and proceed to try to start the bike.
The photo is the exact setup I used to run this single cyl Yamaha when the factory loom was trashed. In the picture I am using the yamaha coil installed in its home because I tested it satisfactorily. The rest is right from the diagram.
Also sorry to keep harping on the term "known good" but it is critical to use known good components to eliminate as many unknowns (do know where the mice chewed?). Once we know the motor will run we can then begin to troubleshoot the sub systems one by one and cure the bike's electrical ills.

[jleonardmca]

the bike runs. i took it for a ride last week. and no mice chewing. the last thing i did to it was put some shiny new points on. with those it ran again, and i drove around the block. i figured i would leave it on a good note and when i came back, i got nothing. no spark. electric start, nothing. kick, nothing. compression, yes, but not even a fart at the points. everything is sound mechanically. as far as i can tell.

[Larzfromarz]

Sounds like a battery. Didn't leave the key on did you?
Congrats though you know it runs!
L

[jleonardmca]

well the battery has some power. kind of abused it getting it to start, between jumping it and whatever. but its still good. the ground wire off it is painted over and looks a little beat up but should be fine. i am going in today or tomorrow to do a little more work but as of now, i tested the new coil. i made the complete circuit off of the bike and got sparks off the plugs. so thats a good thing. it really looks like the coil got fried from the key being in the "on" position and the points being connected. bad luck i guess. but it seems like the most likely cause of the problems. hopefully i can get a video posted in the next day or two, show this thing buzzing around salem. anyone in this area? or know anyone who works on these around here?