Signs scooter is simply running too rich?
Post Reply    Forum -> General Discussion
Author Message
Member
Piaggio Typhoon 125
Joined: 15 Sep 2018
Posts: 11
Location: Southern California
Wed Dec 05, 2018 10:13 pm quote
Hello,

Some brief recent history first:
Scooter: 2014 Piaggio Typhoon 125 at 11.5k miles
-Oil Change at 11.4K
-New Spark Plug at 11.4K
-Valve Adjustment at 11.4K
-New Transmission Belt/Rollers at 10K
-New Battery at 9K

I've been having a recurring issue ever since the cold weather started where it would have trouble starting in the morning, so I tried my hand at adjusting the idle and that seemed to work. But the issue caught up to me and now it's been having issues starting back up midday after I've been riding it for quite a while. What's alarming is that it would occasionally idle at high rpms (the rear wheel would spin FAST). So much that I would have to hold down the brakes at stop lights to keeping it from budging.

Yesterday, the engine cut off as I was waiting for a green light (around midday) and just would not want to start back up. First time it turned off on me and would not start up again. I noticed what seemed like an oil leak from the air filter and it smelled like fuel (something pretty strong). Typically it just does not want to start up after it's been warmed up for quite a while (once again, around midday). The trend I've noticed is that it will start up after I leave it alone for a few hours to cool down. I've tried lowering the idle adjustment and it seems to work for a day or two until the issue (idling at very high rpms) catches up to me again.

Another possible indication is that it starts up easily in the morning. Could this simply be an idle adjustment issue or something greater?
Addicted
Kymco Downtown 300i ABS
Joined: 09 Feb 2008
Posts: 1004
Location: UK
Thu Dec 06, 2018 12:58 am quote
The smell of fuel suggests possible flooding if its a carb model ( I assume it is as you have idle adjustment). Fuel can also accumulate in the air filter due to recirculation from the breather system/evap. system. There can also be issues with air leaks into the inlet tract ( bypassing the carburettor) if the rubber cracks. Is the carb a CV type with a rubber diaphragm? If you are not sure can you post a picture of it? When it refuses to start try gently opening the throttle fully and holding it open before trying again. Does that make any difference?
Molto Verboso
2016 Vespa GTS300ie abs/asr/ess Settantesimo '70'
Joined: 11 Jun 2011
Posts: 1632
Location: Not really sure but I think somewhere in the engineering dept, Britishland, nr Urop
Thu Dec 06, 2018 1:20 am quote
Agree with Roadster. It may also be the carb float is sticking causing the engine to flood. Make sure to clean out the airfilter if fuel is dripping out as that will make it run extremely rich. Ulitmately, this sounds as if the automatic choke is sticking that's why starting was difficult in the first instance. It may also indicate the choke is stuck on by some amount causing your midday starting difficulty.
Member
Piaggio Typhoon 125
Joined: 15 Sep 2018
Posts: 11
Location: Southern California
Thu Dec 06, 2018 2:49 am quote
I'll try to post some pictures tomorrow. But yes, I did try giving it some throttle as I held the power button yesterday to no success (right after it cut off). These past two weeks whenever it has issues starting it will attempt to turn over, but never fully engages (even with some throttle).
Addicted
Kymco Downtown 300i ABS
Joined: 09 Feb 2008
Posts: 1004
Location: UK
Fri Dec 07, 2018 12:59 am quote
Chilly-Bin wrote:
I'll try to post some pictures tomorrow. But yes, I did try giving it some throttle as I held the power button yesterday to no success (right after it cut off). These past two weeks whenever it has issues starting it will attempt to turn over, but never fully engages (even with some throttle).
That introduces a new factor, are you saying that the engine does not spin over on the starter? Is that when cold only or also when hot?
Sponsor
Granturismo 218
Joined: 04 Feb 2013
Posts: 4750
Location: South Carolina
Fri Dec 07, 2018 12:29 pm quote
If the idle is turned up too high, it is harder to start a CVT carbed scooter. Once you get it really warmed up (20 minutes or so), set the idle, then set the air/fuel ratio. If you turn the mixture screw in all the way and the bike doesn't die, your idle is too high.

Also, I'm pretty sure they still seasonally change the gasoline in California, and a small single cylinder engine with a fairly inexact fuel delivery system will require more adjustment seasonally and as it ages and the scooter and carburetor both wear out, than what you are used to with most modern vehicles. .
Ossessionato
09 190s taormina
Joined: 08 Apr 2010
Posts: 2045
Location: Googleville
Fri Dec 07, 2018 4:01 pm quote
Intermittent high idle? Sticking throttle cable or intake air leak?
Veni, Vidi, Posti
Neutrino MP3 492.7 AK, 2013 Moto Guzzi Norge
Joined: 29 Mar 2008
Posts: 20977
Location: Kingston, Tennessee, Tn
Fri Dec 07, 2018 4:19 pm quote
I see your from southern CA, I suggest you take it in to VSO and have them service it.
Member
Piaggio Typhoon 125
Joined: 15 Sep 2018
Posts: 11
Location: Southern California
Fri Dec 07, 2018 9:16 pm quote
roadster wrote:
Chilly-Bin wrote:
I'll try to post some pictures tomorrow. But yes, I did try giving it some throttle as I held the power button yesterday to no success (right after it cut off). These past two weeks whenever it has issues starting it will attempt to turn over, but never fully engages (even with some throttle).
That introduces a new factor, are you saying that the engine does not spin over on the starter? Is that when cold only or also when hot?
Hmm..not too familiar with those terms. I'm still very new to this. I'd say the engine turns over, but won't 'catch' if that makes sense.

This issue seems to occur when the engine has been running for a while (e.g. when I make my third stop of the day to pick up something quick from the store). Also, it starts almost too easily in the mornings. These past days I've just been using it strictly for commuting out of fear that I'll be stranded again. It seems to be more reliable when it's cold.
Addicted
lx 50
Joined: 09 Oct 2017
Posts: 560
Location: Brighton
Sat Dec 08, 2018 12:00 am quote
My LX had a very similar issue after a service by my local Vespa shop.

Hard to start, a different idle at every set of lights.

Turned out when they’d done the service they’d tugged the air intake tube out of the air box. It visually looked connected but you could move it away if you tried. Pushed the lip all the way home again into the air box and problem solved.
Addicted
Kymco Downtown 300i ABS
Joined: 09 Feb 2008
Posts: 1004
Location: UK
Sat Dec 08, 2018 12:53 am quote
northernerbill wrote:
My LX had a very similar issue after a service by my local Vespa shop.

Hard to start, a different idle at every set of lights.

Turned out when they’d done the service they’d tugged the air intake tube out of the air box. It visually looked connected but you could move it away if you tried. Pushed the lip all the way home again into the air box and problem solved.
That sounds very plausible. When it gets hot the tube might even collapse inwards and choke the engine up.
Member
Piaggio Typhoon 125
Joined: 15 Sep 2018
Posts: 11
Location: Southern California
Sun Dec 09, 2018 7:13 pm quote
northernerbill wrote:
My LX had a very similar issue after a service by my local Vespa shop.

Hard to start, a different idle at every set of lights.

Turned out when they’d done the service they’d tugged the air intake tube out of the air box. It visually looked connected but you could move it away if you tried. Pushed the lip all the way home again into the air box and problem solved.
I'll take a look into that. So this evening I took it for longer ride (10 miles nonstop) and made a quick stop to the store on my way back home. Everything was working fine prior until after I made the stop. As I was waiting to pull out of the parking lot the engine cut off. I tried restarting to no success. I tried again while giving it some throttle and it was able to start, but the engine cut off soon after. I was only a mile or so from home so I pushed it back. Halfway through I decided to try again and this time while attempting to start (with some throttle) I noticed what seemed like white smoke coming from the exhaust and a strong smell (again).

I've also been scouring the internet and some possible issues that come up include engine flooding. But could that be possible? If so, it would have to be a recurring issue because it seems to work when I ride shorter distances that are spaced out rather than a long trip at high speed. It seems as if it's overheating. Once again, I'm very new to this so my mind is all over the place.
Member
Piaggio Typhoon 125
Joined: 15 Sep 2018
Posts: 11
Location: Southern California
Sun Dec 09, 2018 8:18 pm quote
Here are some photos btw, I'll try to post a video if I can figure that out.. Sorry, looks a bit messy in there.


Update: I was able to start it up with a bit of work after letting it cool down for two hours or so. But, I'm afraid this issue will reappear under the same circumstances.

Update 2: I tried tightening the air intake valve and it seems pretty sturdy already. Maybe I'll try again tomorrow morning when I can get a better look.

1 scooter.jpg

IMG-0224.JPG

Addicted
Kymco Downtown 300i ABS
Joined: 09 Feb 2008
Posts: 1004
Location: UK
Mon Dec 10, 2018 12:25 am quote
That's a CV ( constant velocity or constant vacuum) type carb. Underneath the round black cover held by the four screws you will find a rubber diaphragm which lifts a slider which controls air and fuel delivery. You need to check this diaphragm for any signs of cracking or pinholes. Also clean the metal slider and make sure it slides smoothly. On reassembly be careful to seat the lip of the diaphragm squarely in its groove. Pinch up the four screws evenly but not over tight.

On a separate note I see that the air filter looks very oily. The small transparent bulb should be removed and drained out. Are you sure that the oil level in the engine is not too high? Check it exactly as per the manual and not on the side stand. Could it be that you are smelling oil rather than fuel?
Missouri Loves Company Rally   vespa scooterwest scooter west Motorsport Scooters   Scooter Parts Company
Post Reply    Forum -> General Discussion
[ Time: 0.3789s ][ Queries: 25 (0.0606s) ][ Debug on ]