Modern Vespa

I was having this problem of hard starting so I bought a new battery to replace the 4 yr. old one and installed a new plug as well.
It tries to start when cold but just can't do it.
Before that, with the old battery, I could get it running in the morning if I just kept holding the start switch until it finally caught. For the rest of the day it would start OK since the engine was warmed up. When I could no longer start at all in the morning I replaced the battery and plug but the same problem persists but not finally catching at all.

What do I need to check out?

Might have a very dirty idle port in the throttle body. Take the air cleaner tube to the throttle body off and you will see a small port in the top left if I remember right.
Get some Throttle body cleaner and spray it slowly into that port while it's idling. It will most likely stall just start it back up. Rev the motor a little and spray as you let up off the throttle.

Unfortunately bad cold starting can be a symptom of many mechanical and electrical problems. Assuming that you have not seen the engine fault light come on when previously running it may be better to start with mechanical checks. Also assuming that your new battery turns the engine over smartly I suggest that first you should check for tight valve clearances. Then if possible check the compression.

After that obtain some ether based cold start spray and attempt to start the engine while spraying this in the intake. If the engine then starts easily it would point to fueling problems. To start from cold the engine needs a very rich mixture and this would normally be supplied by the injector being open for a far longer period than normal.

We're having a slightly similar problem - first we had just a dead battery , however now after trying two different brand new batteries in it - neither one works - no lights, no staring - nothing.

If we could only just get it started once we would take it to the shop for a full checkup. But right now it's DOA even with a brand new battery - maddening!

I've read some things off and on about fuses being blown but no clue what to look for and we aren't mechanics or electrical engineers so voltmeters etc. are not possible for us.

Sounds like maybe a blow fuse. You don't need to be a mechanic or engineer to check on the fuses. Just need a manual to show where they are, and maybe a screwdriver to open up the fuse covers. It's easy enough to do these simple things, that is if you want to.

I started thinking about this and thought I'd try the "spark" test just to see if either one of the brand new batteries actually had juice. A simple wire from - to + quickly brushed up for a millisecond should result in a small spark to tell you there's something going on.

Neither one showed even a glimmer of voltage. So back to the store where we just bought the 2nd one - and exchanged it for another - but not before trying the spark test again in store before buying - voila - battery #3 was a success.

We're back in business. 1 in 3 chance of getting a working battery is not very good odds - either that - or really bad luck.

Oh wow, I wonder what store it was that sold you dead batteries 2 out of 3. That's not good at all...

I don't expect the change a battery anytime soon with 3 EarthX Batteries.
But sounds like bringing a Volt Meter with you may be a good idea before leaving the Retailer.

I keep one of the Batteries + AGM 14BS as a spare on a Battery Jr Charger for me, or for Friends who live near me. They borrow it every now and then to test, or I have them pay me back by giving me another Battery. They always seem to fail in the Winter coming out of Waffle House after Breakfast before we started on our Ride.

Keith,
Marietta, GA

Cleaned the idle port with throttle spray...that did it!
Thanks a bunch

Dennis

Bad battery #1 - Amazon
Bad Battery #2 - WalMart
Good Battery #3 - WalMart - probably wouldn't have gone back for another but had to return the bad one anyway so it was a matter of convenience to just check another one and see.

I would definitely recommend taking a voltmeter for any local battery purchase after this experience. But one would have to own a voltmeter first. That's not a common household thing and buying one just for the purposes of testing a brand new battery seems ridiculous.

You can get a digital voltmeter for $20 or even less. You don't need a lab-quality instrument to check a 12V battery. A proper load tester is best, but you can learn a lot just by testing a battery's voltage before, during, and after a start/stop.

I forgot to mention that the air filter and housing needed cleaning...another factor to consider with hard starting.
The bike runs and starts excellently now.

I thought your lifestyle choices changed?