70cc questions

[Peter Juice]

I just bought a 2003 Vino 50 for prrrretty cheap. I'm guessing the compression is pretty low (difficulty starting, poor acceleration/top speed, etc) so I ordered a compression gauge to check. I'm assuming I'd have to just purchase the 70cc kit if I want to repair it. I want to do this as a hobby, so I don't care about the difficulty and I'm really good at following instructions.

What is the difference between the 70cc kits available here? 10mm and 12mm? As far as I can tell this thing is stock besides the exhaust and variator mods. It also looks like there was a larger opening cut into the air filter box. Is there anything else that I will need to accomodate a 70cc kit? If so, what else might I need to get this thing going? If you think the 70cc kit isn't the way to go, what do you recommend?

I do appreciate the help.

[csfieldmusic]

Low Compression if that is your problem is normally due to worn out piston rings. This can be fixed with a new set of rings for about 12 bucks.

Difficulty starting, poor acceleration/top speed, etc could be due to other things besides low compression.

1. Bad spark plug

2. dirty carb

3. badly tuned carb

4. Bad gas

5. week coil

I would first check the plug, clean the carb, change the gear oil, check the 2 stroke oil and consider changing the gas if you think it may be older than a couple of months. These are the first things anyone should do when buying a used scooter that is not running perfect. Also check the airfilter and make sure it is in good shape and fairly clean. If not wash it, let it dry and put a little 2 stroke oil on it.

If the carb is not tuned very well the motor will be hard to start, bog through out acceleration and not top out at maximum speed. IF the carb is dirty, and they do get dirty especially if they have been sitting for awhile you will have similar problems.

How fast are you going at wot? A de-restricted vino should hit around 40mph.

I would also check the tire pressure as this can effect top speed.

Another thing I would check... And I have only seen it once... Make sure you have 2 stroke oil in the oil tank. I recently got a vino that had 10w30 in it!

If you decide to go with a 70cc kit you have several options.

You can install the 70cc kit alone. IF you do this I recommend you go with a larger main jet. one size up. IF you go this rout be sure to check your plug often to make sure you are not running lean. This is why most people go with a larger carb and upgraded exhaust. to avoid running lean. With proper tuning you can run a 70cc kit with stock parts. Just be carefull

The 70cc kit will increase your power and top in pretty well.

IF you want to take advantage and get more out of your kit you will need to add a larger carb 17mm or a 19mm carb. This will allow more fuel and air so you will get even more power out of the 70cc kit.

Sadly, installing a new carb on a vino requires modification to the throttle cable or just replace the throttle cable. The vino has a push pull system and most carbs use a single cable throttle.

These mods alone will get you going pretty good. But there is more you can do still.

Changing the exhaust with a performance pipe will give you a better power band giving you even more speed.

By changing the variator out you will be able to tune the motor better to the power band by changing the rollers.

You can also change the clutch springs to stiffer ones to allow the clutch to engage at higher rpms. I personally do not like changing clutch springs as this causes the engine to rev higher before you start to move. It also meens when you start to move... you move, making it a little harder to ride slow in a parking lot and when you do ride slow you are very loud.

Most people tune scooters in stages but this is not required. You can upgrade in any order you want. I would not have a problem with starting with the 70cc kit.

Here is what most people do.

1. Pipe, variator, rollers and clutch spriings

2. 70cc Kit, carb, jets, air filter, spark plug, maybe a stiffer torque spring too

3. Large tires and Shocks

4. Clutch

5. Upgears

Some people change the reeds out with carbon fiber ones. Some people also change the belts out with a kevlar one or a slightly longer jog90 belt.

If I were you, I would get the Vino running perfect in stock form and then start mods one at a time, document what the results were and decide from there if your goals have been met. If not move on to the next mod.

[harry]

the 10 or 12mm choice is determined by what size
the piston pin is on your scooter
on a vino its a 10mm....

oilyhans

[Peter Juice]

Thanks a lot for the great info. It's Sunday which means it's scooter fixing and football watching day.

Compression is 120 psi, which sounds right. Tire pressure around 25 psi. Cleaned out carb and jets with guitar string and cleaned air filter. Filled with 2 cycle oil. Wot now gets me to around 35mph (20 on slight grade) with bad acceleration with me at ~190lbs. I verified a derestricted pipe, and I'm fairly confident the variator as well due to a stripped screw head on the metal casing... Trying to remove that, so we'll see.

How does my plug look? Looks rich to me.

http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs927.snc4/74073_1553057031878_1398720251_31727214_1654138_n. jpg

[Blackbomber]

I'm always a little unsure, but aside from being obviously wet, I would not say that plug looks rich. It has a nice even brown color on the electrodes and insulator. There is definately oil deposits. Perhaps the oil mixture was rich, but I wouldn't say the air fuel ratio was fuel rich.

Pipe derestriction does not mean the pipe is not carbon plugged, so keep that in mind. There are threads on this forum describing the "drain-o" pipe cleaning method. I think CSFieldmusic actually wrote that one.

Next time around, don't use guitar string (unless you play classical, with nylon strings). Anything harder than the brass of the jets risks damaging them. I use aluminum wire.

[Peter Juice]

Cleaned out the pipe using the drain-o method and still getting bad acceleration with possible misfire. I may try it again and allow it to sit for longer before rinsing it out.

Hoping to find some time tomorrow evening to keep tinkering.

[BWSman67]

Make sure the plug is properly gapped as well.

[csfieldmusic]

How is the scooter running now?

[Peter Juice]

It's running about the same. A little better after the carb and pipe clean. I checked out the variator derestrict the other day and found that a PO had already performed that mod. I also noticed he broke off some of the variator pulley fins, is this a problem? While I still have that stuff apart, I ordered a new drive belt.