First light (Columbia/Solo)

Got the Bosch double-ended puller from Chris@MWH today; nicely made tool, looks like it will outlast my use. I'd prefer that it had a roller contact, but so it goes - it still works.

Took the mag rotor off of the Columbia, and got a chance to inspect things - not as bad as I had initially assumed. Points were nasty, but a little filing & solvent got them making acceptable contact again. I don't know how others test points, but I use an ohmmeter. If they are more than 2-3 tenths of an Ohm, they are not good - in my way of thinking. Anyway, they are pretty badly worn, and will need to be replaced sometime soon. For now, they are OK.

Just like that, the spark was back. Looks big & bright.

Couple of shots of the PB carb cleaner into the intake manifold (there's no carb on it) and it started and ran on the first kick. No need to pedal it, just a good stout kick-over on the stand. Did it twice again, and so far, the motor sounds solid. This is a good sign, and very satisfying.

Time now to apply for a plate & title. But next, I need to assemble a fuel system for it. Rusty tank, no petcock or line, plugged up carb, and a broken throttle cable. Once again, I'm amused that another of the bike's systems is broken in pretty much every possible way. Cheers to EK for supplying the needed parts!

More to come. Thanks for reading.

Re: First light (Columbia/Solo)

Sounds good


Live to ride, Ride to work

Re: First light (Columbia/Solo)


That's great! :o) I wonder if some kid owned that moped and broke everything, or had a wipeout.

I'm surprised that you were able to get it to start just by kick starting it due to these engines' high compression. Are you certain compression is at normal levels? (I'm not surprised it started on first try- these engines are great, but surprised that it just took a good kick start.)

Before I bought my NOS engine, I had the original engine on it. I had to pedal start it by riding it like a bicycle and pedalling say 2-3 times and it'd start fast.

When I got my NOS engine, it needed the same amount of energy to get it started. The only differences I noticed between the two engines- NOS engine had slightly better acceleration probably due to new rings, NOS engine ran more smoothly, but other than that, they felt almost the same.

Anyhow, I'm glad that things are going good for you with the ped. I know you'll love riding it. These mopeds are slightly bigger than the average moped, or at least feels like it. :o)


Re: First light (Columbia/Solo)

P.S. The reason why I had to ride it like a bicycle rather than starting it on the stands is because the kickstands for these mopeds bends EASILY. High Compression=stress on kickstands.


Re: First light (Columbia/Solo)


You may have a point about the compression.. I really need to put a gauge on it and see what it is.. soon. For what it's worth, it does feel pretty stout - about like kicking over a Honda 450 twin. My 200lb weight is a lot of help in this department.

Having worked on motorcycles over the years, I've gotten pretty good at kickstarting just about anything. When I do, I never straddle the bike - I always stand on the offside (right side of the bike) facing forward, and kick it over with my left leg. This assumes it has the kicker on the offside. If it's on the nearside, then I stand over there and kick with my right leg.

Re: First light (Columbia/Solo)

Oh, about pulling the magneto rotor on this bike - I found something odd.

Unlike the Puch, the Solo has the mag installed on the right-hand side of the engine, and it rotates clockwise. On a clockwise-rotating flywheel, I expect to find a lef-hand threaded nut - as the direction of rotation would tend to loosen the nut otherwise.

Not on the Solo.. the magneto nut is a standard right-hand thread. I'm sure this works fine, but it was a little surprising.

I also measured the resistance of the plug cap, expecting to find 5-10K ohms - but it measures almost exactly 1K ohms. Don't think I've ever seen a 1K plug cap in my life. Is this correct?


Did a test, and it's pushing about 145lbs. I'd call that fine.

This is on a cold engine, that has been sitting for many years - so this figure will probably go up once it's been run a while.

What does your NOS engine read, EK?

Err, plug wire resistance?

Bill, I cut the stock plug wire off my 50V because I thought it had been permanently crimped onto the plug (this was before I realized that the plug top could be unscrewed.) I bought an automotive plug wire with the rubber boot, intending to solder it to the half of the plug wire left attached to the condensor. I was quite surprised to find that it contained no wire, only a resistive plastic film, so I ended up just using the boot soldered to some 18 gauge wire. That worked fine (until I killed my engine), and would only have had a resistance of a fraction of an Ohm. Do you need resistance there? Because I'm pretty sure the stock plug wire (on my bike) was just copper wire as well. Maybe the 50V's condensor has that resistance built in? What's it good for-- limiting the current drawn from the magneto?

Re: Err, plug wire resistance?


Standard practice on motorcycle (and moped) engines is to use a soild copper-core plug wire, with a resistor cap (sometimes called a supressor cap). The resistance of the cap is almost always 5K. I've been doing some reading, and apparently the 1K figure is much more common on engines with magneto ignition.

The resistance is there to supress radio-frequency interference (RFI) generated by the ignition. It also has an effect on spark quality and plug life - it increases the duration of the spark, and reduces erosion of the plug's electrodes. This helps to keep the gap stable over the life of the plug.

In addition, the resistance of the cap works with the internal impedance of the ignition coil, to improve power transfer through the wire - if you view the plug wire as a transmission line (like for RF) the cap acts as a terminating resistance, which improves power transfer to the load (plug).

In high-energy systems (especially CDI systems) the resistance also protects the ignition coil and control module from burn-out, due to excessive current.

However, It does not affect the peak voltage of the ignition - that is a function of the coil's output voltage, and the spark plug gap.

Lastly, the automotive cable you were using really isn't suitable for a moped ignition. It might still spark, but you should notice some power loss, and less MPG of fuel. The core is constructed of graphite-impregnated fiberglass, in a plastic sheath, if I remember.

Re: Err, plug wire resistance?

So, I'm almost positive that the stock wire was just that, a stranded copper wire. It terminated in a stiff, solid wire crimped around a brass collar, and that collar fit over the threaded plug post, then the fat plug post was screwed on. Man, I wish I'd known that post unscrewed before I cut it all off! Do you think you could do me a favor and measure the resistance of your 50V's plug wire? I don't want to burn out my coil or anything.

Anyway, sorry to hijack your Columbia thread, it sounds pretty sweet. The water cooling is passive, right-- no radiator or pumps? Does the improved cooling let the engine rev higher?

Re: Err, plug wire resistance?


I can tell you for a fact that the stock wire on the 50V was stranded copper - near zero ohms. When I found the bike, it had a generic NGK style 5K resistor cap on it.

Somewhere I have an OEM cap, but not sure if it's good. I'll try to check it out at some point soon. So far, the 50V runs perfectly with the 5K cap.

Water cooling on the Solo is passive.. I've been wondering myself just how much it does, but my guess is that the main benfit is evening out the heat in the cylinder. I'd like to know what Solo said about it.

Water cooling

Passive cooling seems pretty weird... water's a decent conductor of heat, I guess, or at least it has a high heat capacity. But I don't think it's better than aluminum, not if it's stationary. I guess the vibration of the engine running keeps it swishing around.

Re: Water cooling

if you run a water cooled solo without or with very little water what would you say would happen? I have one and its been shotty ..I took it to the local repair guy,and its been two weeks..he has no idea.. he got it to run..but it shuts off or sputters out or just totally idles wrong..

Re: Compression


I'll have to buy a compression gauge sometime. I use the old fashioned hick test where I put my thumb on it and pedal. If it pops off, it's great. ;o) (but if I had to guess, it'd have to be over 150 lbs at least)

I can tell you, though, I'm 290 lbs, and standing next to my moped & kick starting wouldn't be enough to start it. Too much compression.

I've got a wedding and baby coming, so it'll be awhile before I get a chance to buy a compression gauge.

Best Regards,


Re: Water cooling

It's a passive cooling system. The combination of the static sleeve/water sleeve and wind helps cool the engine down.

I have run a Solo engine without water for the heck of it, for about 5 minutes, idle. No problems there. I think it's just for when you're going full throttle. Then the benefits kick in at that point.


Re: Err, plug wire resistance?


I'd like to know what Solo says about it too. Unfortunately, the company no longer manufactures moped engines. They only manufacture weed wackers and lawnmowers, I think.

KKM was the last company to own/build these mopeds, but they went out of business sometime in the past 2 years or so.

I had to spend over 20 hours on the internet searching for information on these mopeds, and I couldn't find anything, pretty much. So I did the next best thing- learned all I could about these engines. It took me to connect with a few guys that knows about these to learn what I did.

These guys got sick of being the expert, so they disappeared. I guess I took their place, for now. :o)


More compression


Hm, if you can't start it on the stand, considering your weight advantage (over me), I guess that says something. I guess I'll know the story once I have it running; if it won't do 35 with me on it, then safe to say it's down on power.

Does your manual state the compression ratio of the motor?

But like I mentioned, I think this bike was sitting for almost 20 years, so I'd never expect the engine to be developing its maximum compression at this stage. Even if it's unworn, there's bound to be some losses due to lack of oil in the cylinder, light haze of corrosion on the piston rings/cylinder wall etc.

Guess I'll just have to test it once I have it running a while, and it's good and hot.

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account