Vino 2 stroke running issues.

[codielee2015]

Hey guys ive got a vino I've been messing with for about a year now. Maybe a couple hours every month or two. I keep having the same problem. I can get it to run and run fine, but every time after about 5 to 10 minutes it revs up on its own, really high (full throttle) sits there doing that for 20 or 30 seconds. Makes a few bad sounding sputtering sounds and then dies. When it dies for a minute or two smoke is blowing out the exhaust slowly. Ive cleaned the carb over and over. Checked plugs. Cleaned gas tank checked lines etc.. My carb bowl float tab (tbe tab that holds it level) broke one time and I plastic welded it back. Ran fine after that. Could that be it? Really what it sounds to me like is its getting gas normally and then somehow somewhere it gets air after 10 or so minutes, leans way out revs up and soft seizes. Any other thoughts? Any ideas where mysterious air would come from after 10 minutes of running?

[codielee2015]

So today I redid the float, made it sit a little higher. Didn't change anything. What I did notice is when the engine starts reving up and I cover the holes for where the petcock vacuum line used to go with my finger the engine calms down for a bit. Eventually it revs back up anyways but it does slow it down for a bit. So now I'm thinking its running rich. But I still don't see why it would start happening after scooters been running for 10 minutes. Seems anything would happen right away. Also doesn't explain the soft seize I appear to be having. I dont wanna buy a new carb and that noy be it. And I don't wanna rebuild the engine just to soft seize it over and over again trying to figure it out. So I'm sort of lost as to where to start. Anyone ever had a scooter that ghost throttled after its been running for a while? Its not the choke does it wether its plugged in or not. Airbox is stock everything is stock. Ive tried air screw all the way in, out. Airbox no Airbox. Vacuum lines covered not covered. Always does same thing. And then sometimes it won't restart for a minute or two sometimes it will. But when it does start it'll run fine again for 10 mins or so then do the same thing.

[pinkscoot]

You have an air leak you need to solve because your scoot is running lean. A 2 stroke engine needs to be a completely enclosed system with outside air only coming through the air box. Possible leaks are airbox not tight, please plug the intake holes on your carburetor. Check your rubber intake it may be cracked, even a small leak can cause problems, trust me I know. The gaskets on your intake can leak. The exhaust needs to be tight. Last the seals on the case, where the crankshaft comes through the case are a seal on either side. The corrode and let air in a reek havoc on the whole system. Plug all of the holes except your intake on the air box, get your engine running and spray carb spray or propane on all of these places, if your engine changes RPM then that spot is leaking. Another way is a leak down test. Look here and it will tell you how to build and use one. report back and let us know what you find.