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My Eternal Project, or the Scooter That Refuses to Live. Any Ideas?

4330 Views 59 Replies 11 Participants Last post by  Unkle Krusty
And the scooter is dead for a third time now...I’m running out of things to replace.

If you’ve not been following my CF Moto saga, here’s a recap:

First Revival

Acquired in November from a fellow Gambler 500 team member. I replaced the battery, the carburetor, and learned the starter solenoid was installed backwards by a previous owner. It sat for roughly two years without running and I made a gamble that I can make the old fuel burn again. While I was successful in that, I made two critical errors:

1. I didn’t replace the fuel filter.

2. I rode it every day for a month, not really ever allowing it to get to running temperatures.

Despite that, the scooter was good for 75mph, impressive acceleration, and it all around it ran absolutely perfectly. I felt I had myself a good score and with actual fresh fuel I’d probably even break 80mph. I proceeded to daily it for a month, taking it everywhere.

Fixing my Original Mistake

I made sure I ran all the bad fuel out of the tank and made sure the tank wasn’t rusty. Then I filled it with good fuel.

I then replaced all the fuel lines, the fuel filter, and the carburetor. I then installed a pod filter. I also closed off the crankcase vent to the airbox. Instead, the crank vents out into the outside. The original problem with not being able to start after getting hot remained, but at least I was no longer fouling my air filter and carb with particulate matter (air filter material) and oil. Top speed was about 40. Figured I would get more speed from restricting the pod filter, but first I really wanted to address the problem with not being able to restart with a warm engine.

Take Three

I decided to replace basically everything else I didn’t touch. I took the panels off and replaced the air filter so I can ditch the pod filter and go back to the factory setup (I still have the crank venting to the outside, though) and not have to jet the carb. Then I replaced any old vacuum lines that remained. All this work resulted in no change. It does cold starts well, but introduce any heat and it’s dead. The engine tries to fire, but it just won’t.

You can get it to start on starting fluid, and then it will go on to run like it’s misfiring and it’ll die as soon as you stop moving...then fail to start again.

Only thing I haven’t replaced is the spark plug (because the bloody thing has a spark plug that requires a bigger socket than the one I have for my smarts), but I fear it’ll be a waste of time.

Is there anything else I’m missing or do you think the spark plug will be my magic bullet?

This was supposed to be an easy project, but it certainly has taught me a lot about motorcycle/scooter repair! If the spark plug doesn’t fix it I’ll probably get rid of it. I’m just not sure how much I would be able to trust it at that point..And I'd hate to do that because when this thing was running well it was an awesome way to get around. 75mph top speed and everything.

For a TL;DR - here’s everything I replaced:

- Battery
- Fuel Lines
- Vacuum Lines
- Carburetor (built in electric choke)(2 times)
- Air Filter
- Fuel Filter
- Oil
- Fuel

Only thing I can think to replace now is little sparky..
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Fuel pump is vacuum based. When I replaced the vacuum lines and fuel lines I went almost clear with everything so I can see it all in action. IIRC, the tank vents through the petrol cap, which I'll probably give a good clean to make sure it isn't blocked.
I'll give that a try! I'll be honest, given that it's a Chinese bike there could be something wonky internal with the engine (valves!) so if changing the spark and trying to vent the fuel better doesn't work I'll probably just get rid of it.
Thankfully, having an IT background means I apply my work to my projects. :) I've ruled out the fuel as the issue after replacing the lines, carburetor, and actually already having done the tests you've mentioned above. It's vacuum based fuel delivery, so I made sure that was good, too.

I have the service manual for this little scoot (poorly translated to English, but it works) and thankfully the valve adjustments are pretty easy as well. I actually didn't know valves could even be a factor here and heck, it's worth a shot.

I see some of these things with 20+k miles on them so they can go for a long time when they do work right.
I do have the ability to give up, but that's usually when I lose attachment to the thing I'm trying to work on. I really really like this scooter, hence me trying to do all I can to get it back working 100%. :)
Depending on how these repairs go it may or may not become my vehicle for May's Gambler 500...which is about the most "metal" way to retire a vehicle from service.

Fuel tank is in front of the seat under the floorboard. The vacuum fuel pump is just in front and under the carburetor. That was one part I didn't replace when I first got the scooter because it appeared to be working. It appears to be doing its job for now, but I'll check it out and I definitely can get a pic later today or this weekend. :)
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Last year I was supposed to take that 150cc Chinese Ruckus clone I have, but I couldn't get my new tyres installed in time. I ended up "Gambling" my daily driver (a mostly stock smart fortwo). We lost more than half the entire field of vehicles at the first offroad park and somehow the little smart with only 5.5 inches of ground clearance wasn't one of them. :D

This year I want to crank up the crazy and bring an even more unfit vehicle. Thought about picking up a beat up Ninja 250 or Rebel 250 because an offroading sportbike or cruiser would be hilarious. But knowing that falling/crashing is a definite possibility I think I'll stick to last year's idea of bringing a scooter that isn't going to pin me to the ground when I fall. That or I'll just run my smart again (because that was hilariously fun).
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Alright, so tonight I will make some progress on this one. I'm getting antsy waiting for the new wires to come in so I'm taking matters into my own hands.

First, I will remove the spark plug, examine it, then replace it with a new one. Then I will test the tank for vapor lock. If this doesn't work, I'll move on to replacing the coil and doing a valve adjustment. If absolute none of those work, the scooter is going to get sold.

A 1984 Honda Elite 125 popped up on my radar and I'll likely pick it up on Friday. The Elite will replace this scooter as my work commuter. If I get this scooter running well again, it'll become my new Gambler, replacing the Ruckus clone. Such will bring me down to just one Chinese bike, and it'll only exist to be an offroader.
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Didn't take you long to turn on the Chinese............
Ah, you got me there! :grin:

Yeah, as much as I can appreciate how stupidly simple a Chinese bike is, I'm very much not liking the trade off of not being able to trust it to get me home.
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Alright, so I’m getting so close to just throwing in the towel on this thing.

Tonight I got myself some new tools to play with and attacked the scooter with them. First thing out was the plug. Well... this is the cleanest used plug I have ever seen. A quick wipe with a cloth had it looking like new.

The scooter started, ran rough, quit, then didn’t start again for the rest of the night without starting fluid. Pulling the plug again revealed it to already have carbon deposits and even a splatter of oil.

Next, I moved onto the tank and to make sure it didn’t have vapor lock, I took the cap off and tried starting with a splash of starting fluid. It actually ran worse with the cap off.

Next, I checked the wires to the spark plug coil and the coil itself. The coil looks undamaged, as does its wires. However, it could still be shot. Took everything apart and put it back together, no change.

Finally, I decided to check its oil. Oil appears to be thinned with some fuel (possible flooded cylinder?) and has the consistency of something between oil and water. Ugh..

Tonight’s session didn’t get me anywhere closer and honestly it’s made me even more reluctant to buy a new CDI, coil, and plug.

Worst yet, I’m getting absolutely no bites on Facebook or Craigslist, so it looks like I’m either going to end up selling it for a massive loss or stick it through to the end.

Alrighty’re going to hear it from probably the biggest Chinese bike fan on here, but.. I wish I hadn't gotten this thing. lol
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Since I'm not getting any offers (not even lowball ones lol) I'm basically going to stick it out since there's nothing else I can really do.

Next thing I'll be looking to do is test compression. Perhaps something much more catastrophic happened than I thought (causing the oil to thin). If that checks out, I'll replace the CDI box. Sooner or later I'll have replaced everything but the engine! :D At least the parts for this thing are cheap and plentiful. A failing CDI would make sense given the scooter is running worse and worse despite my fixes.
Truth be told, I set a limit for myself on this one. If my latest laundry list of checks (CDI, coil, completely new plug, compression, valve clearance, etc) doesn't pan out, I'm calling it game over. I sometimes have a problem with getting into a sunk cost fallacy, but not this time!

This is especially true since I already have a replacement scooter lined up that very much isn't Chinese. :)
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The scooter I want to replace the CF Moto with is this Honda Elite 125. I'm not a fan of the massive windscreen, but that's nothing a Dremel can't fix. Those knobbies will also have to go, but at $600 I can't complain. It has an awesome pop-up headlight, runs well, has a clean title, and is allegedly ready for the road. I want to bring it home, give it a nice wash, and enjoy a comfy ride around town.

I'm still hoping to hold on to the CF Moto for the Gambler 500, but there's always a chance I won't get to see myself taking it through mud, water crossings, and some jumps. :D Either way, weeding out the Chinese scoots will bring me down to just two projects (one bike, one car), and that's something I'm actually excited about.
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You do realize I am pulling your leg right?
I know you are! :D Though to a degree you are inspiring me to keep looking for new fixes.

I probably won't make much progress this weekend as I can't find the darned CDI box on this thing. The wires the coil plugs into lead to a bundle of more wires that disappear into an area hands clearly weren't meant to go. So, it's time for some sleuthing!
Ah, see...I've been cursing at it in German and Spanish all this time! :D

Took another look at it this morning since it's super bright and sunny outside. I've located where the CDI likely resides. It's either on top of the fuel tank or in the dashboard. The coil's wire disappears into a bundle that leads to the front. In fact, a whole slew of wires seem to go up front.

I've been thinking about this a lot, and I do remember something that sounded like electrical arcing in the dashboard a few days before the scooter died. I'm beginning to think that maybe the CDI is damaged and is getting worse and worse over time. So my next step from here is to take apart the dashboard and see if the CDI is chilling out in there.
More good news! I found out how to adjust the valves, it's actually pretty easy and I'm excited to do it!

Meanwhile, I found my replacement for the Chinese Ruckus clone.

This is a 2012 Sym Symba. Back in the day, Sym used to build the Cub for Honda. Then when Honda and Sym split, Sym continued to build the Cub under license for markets outside of Japan. Sym brought these motorbikes to the US about a decade ago. They were essentially the same bikes they've been building for decades, but with some technical upgrades. This example has 11k daily ridden miles and is ready for a new home. The owner collects bikes like me and actually offered to let me ride his Harleys after finding out I've never ridden one. :)

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IIRC, the Honda Cub (not counting license built versions like the Sym) is the best selling vehicle of all time. :)

Quick glossing through Sym forums seems to squash any quality doubts. These are super simple so there's not much to go wrong. To be specific, these are Super Cubs but with 101cc Honda dirt bike engines.
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I will on Monday when I go to pick the Sym up! :)

I feel I'm getting super close on the CF Moto, so next week I'm going to do what's basically a "hail mary pass" and see if I can squash the problem once and for all!
Fear not, I'm actually taking off work tomorrow and making it a big motorcycle day. New CDI, plug, and coil arrived in the mail today.

Tomorrow I replace those parts then adjust the valves. If none of the above works that's where I'm going to draw the line and call it quits.

If the day goes the way I want, I'll have the scooter finally fixed (and it now being used for the Gambler 500), that cute Sym as my around town toy, and the Chinese Ruckus on the marketplace looking for a new home.
I did it!!! :D

Not only did I get the CF Moto running again, but I cleared a new GPS top speed!

Here’s what happened:

First thing first, I started the scooter to get a baseline. It took a LOT of starting fluid and when it did get going it puffed out enough white smoke to compete with a steam locomotive.

I decided to change the oil since the oil it had already was pretty thin. This scooter has the easiest oil change ever!

After getting the engine warm, I changed the spark coil. I also found out that the spark plug was gapped way too close.

This resolved the issue where it wouldn’t start hot. Now it starts hot... barely. It still ran like garbage, so I considered the coil to be a factor, not the cause.

Next, I located the CDI. It was ahead of the battery tray and on top of the fuel tank. Unfortunately the CDI I bought was the wrong plug configuration even though I ordered the correct one... thanks, Amazon! I crossed my fingers that the CDI was good and moved on.

Next up, I found the valve adjusters.

Since the clone's engine is basically the same thing as Honda's engine, I decided to follow Honda’s instructions for mechanics..

Unfortunately, I couldn’t get the scooter to start and stay running without the engine making horrifying tapping noises. Meanwhile, the scooter still spat out white smoke. Whenever I adjusted the valves to a position without the tappet noises, the scooter would die and not start without a lot of cursing in Mandarin and starting fluid.

I was just about to throw in the towel when I decided to go for broke. I took the carb from my first resurrection of this scooter and gave it a thorough cleaning. Considering the carb it currently has was brand spanking new without even a mile on it, I figured I was wasting my time.

I installed the carb from the first resurrection and gave it a go. It started without starting fluid this time and when I adjusted the valves properly? It ran even better. Within a minute the white smoke cleared up as well.

I reluctantly took it on a test ride, but the little thing blew me away. It seems to perform even better now than the first time I resurrected it. I hit a GPS verified top speed of 80 mph. Not bad considering I’m not at all lightweight.

Uh...well... unfortunately this means that I want to keep it. This adventure has taught me so much about this scooter that I’d feel bad giving up on it after this victory. It also doesn’t help that even running I won’t be able to make my money back on it. So screw it!

To make it more “mine”, I got rid of the top box. The latch broke a few weeks ago anyway, so nothing of value was lost.

I was going to celebrate by bringing home that Sym...but looks like someone beat me to it and that Honda Elite. Darn. Oh well, at least I have this thing going again!
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