Piaggio 150cc Issues.

[xaos29]

Hello all,

I will try to be as thorough and concise as possible:

1. Scooter: 1996 Piaggio Hexagon 150 2T
2. Years owned: 1
3. Replaced Parts: Belt, Variator Drive Pulleys, Rollers, Clutch Return Spring, Tires, Front and Rear Shocks.
4. Maintenance: Cleaned Air Filter, Replaced Spark Plug a month ago, Use Silkolene Injector Oil, Replaced Antifreeze with Engine Ice, Replaced Gear Oil.

Condition: When purchased, it was obvious the scooter was neglected and in need of repair. The previous owner appeared to have little patience for the Hexagon, and seemed to be happy to be rid of it (I guess he thought 2 strokes were fast...like sportbike fast, and was disappointed in his investment). The only repair he admittedly made was to replace the CVT belt. I have tried to get the Hexagon operational and to a reliable state, but restoring it to its former glory would be too expensive. The next part to replace is the electric start motor, and whatever you forum members suggest after reading.

Issues:
1. When accelerating, the scooter will bog down and begins to stall past half throttle to full throttle. If kept wide open, the scooter will stall and will not start up again for 10 minutes or so.
2. Recently, the scooter will backfire when experiencing the the above conditions.
3. The problem seems intermittent, and usually occurs when I take the scooter over hilly terrain.
4. There seems to be a peculiar odor, almost like a burning smell, when the scooter starts up.
5. I know 2 strokes are supposed to smoke, but the scooter seems to smoke more than it ought.
6. The exhaust is hollowed out (no guts) and has to be replaced.
7. At times, it takes a few tries to start the scooter, and it will run rough, and occasionally, it will stall out.

I'm neither a mechanic, nor remotely mechanically inclined. Quite honestly, other bulletin boards have not been very helpful. I chose this forum because 90gtvert posts frequently on youtube. And you all seem like good people willing to help.

Here is a video link from last August. The metal rattle is the result of wrenches in the "trunk":

www.youtube.com/watch?v=LW1SQ3DxwwM

[chehystpewpur]

Hollowed out exhaust is bad on a 2 stroke. Its supposed to be designed to suck the exhaust out then spit it back towards the cylinder then back out at the right intervals to lubricate and mix the air fuel and oil charge coming into the engine and cylinder. My best guess is thats contributing to the poor performance and stalling under load. I had a 50cc that would barely run then overheat bog down and stay off for about 10-15 mins due to a faulty exhaust that was plugged instead of free flowing. If they aren't too expensive id look for an exhaust pipe so that at least that aspect is working properly. They act as a camshaft for a 4 stroke because 2 strokes have like 3 moving parts.

[2TDave]

My first thought was you were running rich but after reading I'd tend to think the opposite and say your lean. You can try up jetting the main jet in the carb but with the exhaust gutted it may be a bear to tune. It sounds like it's getting hot and shutting down. Make sure the shrouds are on the cylinder. Without them it will overheat also. Main jets are a few dollars so you may want to give that a shot before investing in a new exhaust.

[moofus02]

Cool scooter. I would say it is lean by your description. The exhaust may be part of the problem
Sent from my SPH-L720 using proboards

[chehystpewpur]

Prolly lean due to the exhaust but why would it backfire if its lean? Thats what im wondering unless the unburnt fuel is just staying in the exhaust or something. I checked the video out and thats one ugly sob yet at the same time I'm jealous lol. I'd love to have a larger 2 stroke. It did sound kind of sickly in the video I might add something is definitely out of wack on it.

[xaos29]

Thank you all for your replies. I thought the main jet may be fouled, but it seems the exhaust is equally to blame. At this point, it seems pointless to rebuild the carb until I have a replacement exhaust system.

The Hexagon is rather an acquired taste in terms of design, but maxiscooters are comfortable rides.

[chehystpewpur]

Jul 16, 2014 12:38:23 GMT -5 xaos29 said:

Thank you all for your replies. I thought the main jet may be fouled, but it seems the exhaust is equally to blame. At this point, it seems pointless to rebuild the carb until I have a replacement exhaust system.

The Hexagon is rather an acquired taste in terms of design, but maxiscooters are comfortable rides.

Honestly I think your right for not messing with it until you get the exhaust. I spent weeks no lie trying to troubleshoot mine till I tried and went from shutting down and a top speed of 20-30 to 50mph right off the bat and ran like a top. And acquired taste just like the banshee 4 wheelers. Ugly as sin but beautiful and amazing performance in their own right. If I had the money id make you an offer you couldn't refuse but alas I'm poor lol. I really hope you get it sorted out though I'm sure that thing is a blast to drive.