OP
UTC

Member
2009 LX150
Joined: UTC
Posts: 17
Location: Bay Area, USA
 
Member
2009 LX150
Joined: UTC
Posts: 17
Location: Bay Area, USA
UTC quote
Just got a 2009 LX150 with only 2.6k miles on it. Previous owner had a oil and filter change done at 2k. Looks and runs good. Except it wont start when cold with throttle in idle position. Needs a bit of twist of the throttle to get it going. And once it does, it will start fine on consequent warm starts with throttle at idle.
Idle is good and stable. Does not shut off or run erratic or anything.
Not knowing how old the gas in it was or how much use it had seen recently I have filled it up (1 gallon) with premium 91 octane gas and added the standard dose of seafoam to it.

What might be going on ? What can I check or do to have a quick smooth start at idle ?

Thanks!
@silver_streak avatar
UTC

Veni, Vidi, Posti
2007 Vespa LX 190, 2011 LXV150ie
Joined: UTC
Posts: 8758
Location: Annapolis, MD, USA
 
Veni, Vidi, Posti
@silver_streak avatar
2007 Vespa LX 190, 2011 LXV150ie
Joined: UTC
Posts: 8758
Location: Annapolis, MD, USA
UTC quote
I'm assuming it's a carbureted model? Nothing at all unusual about that if it is.

You are probably just used to fuel-injected engines.
UTC

Hooked
'08 Vespa LX80, '07 LX50
Joined: UTC
Posts: 377
Location: Honolulu
 
Hooked
'08 Vespa LX80, '07 LX50
Joined: UTC
Posts: 377
Location: Honolulu
UTC quote
You could make sure the connection to the electric choke is solid. If you are mechanically inclined you might take it off and inspect it. It could be stuck closed. It's a plunger type needle valve gadget. Maybe it just needs to be driven a while to clean out the carb better.
OP
UTC

Member
2009 LX150
Joined: UTC
Posts: 17
Location: Bay Area, USA
 
Member
2009 LX150
Joined: UTC
Posts: 17
Location: Bay Area, USA
UTC quote
Its a carb engine.
I noticed that if I keep the start button pressed a little longer - like maybe a total of 5-6 seconds - then it does start on idle too. I was giving up early, I mean its not like it doesnt start at all, it actually does. But its still does feel like a stubborn start, not a quick normal start.
And what I mean by cold/warm is not the actual temperature of the engine but just the very first start of the day (cold) followed shortly by another start right after that (which is what I referred to as warm).
I will find the choke and check it out.
@greasy125 avatar
UTC

Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14995
Location: The state of insanity, SoCal
 
Sergeant at Arms
@greasy125 avatar
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14995
Location: The state of insanity, SoCal
UTC quote
chances are you have a lean idle jet. bump it up to a #38 and you should be fine.

but laying on the button for a few seconds with a carb'd model isn't that out of the ordinary. next time give it a twist or two of the throttle first and see if that helps in the giddy up.
OP
UTC

Member
2009 LX150
Joined: UTC
Posts: 17
Location: Bay Area, USA
 
Member
2009 LX150
Joined: UTC
Posts: 17
Location: Bay Area, USA
UTC quote
Can a clogged air filter cause this ?
I removed the air filter to check and I am not too familiar with oiled foam filters but to me it looked a little soggy and old. Scooter has 2.7k miles on it. So I dabbed up the extra oil, did get some oil on the paper towel. While there were some traces of oil in the air compartment there was nothing dripping or in the bulb. I also dusted it off. After putting it back there is a marked improvement in this idle throttle start response. It starts much better now.
I have a new oem filter being delivered on Sunday.

Question about filter placement - when putting the filter back into the compartment should the filter element be placed in the lid or should it be placed in the compartment on the scooter side and then the empty lid put on ? Looking at the ductwork it seems like if the filter is placed in the lid then unfiltered air could flow into the engine. Goofy emoticon
⚠️ Last edited by scoot_pfm on UTC; edited 1 time
@jimc avatar
UTC

Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 44220
Location: Pleasant Hill, CA
 
Moderaptor
@jimc avatar
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 44220
Location: Pleasant Hill, CA
UTC quote
It's pretty normal for a carb'd bike. As Greasy says above. Give one or two twists before you hit the starter, and this sends a squirt of fuel through the accelerator pump, giving an instant hit of gas fumes into the intake manifold. Then it should start easily.
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