Modern Buddy

My wife's 125 Buddy seems to have a recurring issue. We routinely carry it on a carrier on our RV. It seems that when I have a full tank of gas when it is transported, we have an issue that the scooter will die when running at speeds over 45 mph. It acts as it is running out of gas then dies. Wait a minute, then it will start and go another mile then do the same thing. I made sure to transport the scooter under a half a tank and the issues seemed to disappear. I unfortunately did not have the opportunity on this trip to run at least half the tank out (and frankly, I forgot about this issue) on this trip as we have been getting snow as late as this last Sunday morning and we were heading out for a trip to Maryland with the scooters. Today, we got up to speed, and her scooter started this whole starving of fuel thing. I have all along thought that fuel was going down the vent line and somehow not letting the fuel tank vent properly causing the problems. After shutting off at some very problematic points in our trip, I just took the gas cap off and we did not have any issues for the rest of the day. It ran great. I just filled the tank to 3/4 when we had to fill up.

So my question for you guys who have taken apart your scooters before, is there a problem with the vent system getting gas into it that explains my issue or could it be as simple as a faulty gas cap that just needs replacing? When this happened before, I changed the plug, fuel filter, air filter and adjusted the valves.

On a side note, I had an issue with my scooter as well. It was running like poo this morning, I thought something was really wrong with it and all of a sudden, a large puff of smoke came out the tail pipe. I pulled over, checked the oil and somehow, I had way over filled it last fall when I changed it. Fortunately I was able to tilt the bike and get some oil out (Sorry environment for putting oil on the ground, I had no choice) to get it to the correct level and it was fine the rest of the day. I put 120 miles on it afterwards and checked the oil level every 50 miles or so to make sure it wasn't changing. It didn't.

the vent is in the cap i believe depending on the year and what the gas cap looks like...take a photo of the underside of the cap and post it...also compare both scooters gas caps and try switching gas caps between scooters and see if the cap is the problem first...1 scooter has a fuel pump and the other is gravity fed...if you find that this is the issue then buy a new vented gas cap or just leave it a little loose or this thread below may also help...you may also want to buy a siphon and pull half of the gas out of the tank and just put it in your car before you transport

http://www.modernbuddy.com/forum/viewtopic.php?t=15318

too bad they don't make these for scooters...you would have only had to crack it to drain some oil into a bottle...i have one on my car and i love it

http://www.fumotousa.com/

Sounds like the stator is failing.

k1dude wrote:Sounds like the stator is failing.

What makes you think that? Seems like a very odd presentation.

Wertles wrote:

k1dude wrote:Sounds like the stator is failing.

What makes you think that? Seems like a very odd presentation.

One of the common symptoms of a failing stator is that the scooter with die, often at speed, and then will restart after sitting a few minutes. The worse the stator gets the more often it will shut down and the longer you will have to wait to get it started till eventually it just won't restart.



Some of the symptoms you are describing are similar to what happens when you overfill the gas tank and gas gets in the evap system(gas can also get in there if you transport the scooter with too much gas in the gas tank.) Once gas gets in the evap system in can take 10-20 miles or more for it to clear out.

If it was my scooter I would go out and ride till the gas tank gets low and only fill it 1/2 to 3/4 full, repeat this a few times. If the problem goes away then you are overfilling the tank, an easy problem to fix. If that doesn't fix the problem there is a chance you are having an issue with you gas tank not being vented. But if running a few half tanks of gas through it doesn't help then it probably is the stator that is going bad.

If it is the stator it will probably fail in a few hundred more miles, at least mine did. Other things that might point to the stator going bad are that it will take longer to get it started or it will die while idling(if you have adjusted the idle speed up recently then that also points to the stator being bad.) You could also check to see if it has a strong spark, even after mine failed it would still spark but it was very weak.

So we put the gas cap on today and had no issues whatsoever. I’m 99% sure it’s gas in the evap system.