Modern Vespa

Hi
Th esaga of my gtl 125! Replaced the fuel pum and carb to address a flat spot. Now I have the problem that the scooter refuses to start when temp below about 9 degrees (48 degrees F), even using jump leads from a car etc

Starts pretty readily at higher temps like after 3 seconds of churning.

VArious peple (JimC in particular) aalways said it was likely to be teh valves. I'm going to recheck them tomorrow as everything else has either been checked or replaced.

IS there a specific guide to the procedure for the 125s - just checking in case I've missed anything.

To check the valves, it's easiest to drop the engine at the back so the valve cover swings towards the vertical. This is best done when doing a full service with the rear tyre and transmission cover removed, and with the centre-stand on a 2" high bit of wood. With both shocks removed the engine will swing down a lot without hassle (though ensure no wires/fuel lines or coolant pipes get strained).

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You can't go wrong following Jim's advice.

You're right. An interesting discovery perhaps.....

I removed the battery from the scooter and charged it overnight (scooter lives outside). I fitted it this morning. I wasn't even going to try starting it as it was still cold weather. However, it started almost instantly and ticks over perfectly!

Could it be that the scooter is very sensitive to the battery voltage/ current which would be reduced somewhat - perhaps a lot - in the cold? I bet if I had charged the battery and fitted it yesterday and left it outside overnight, it wouldn't have started.

That would help explain a lot - I never really "got" why the valves / engine could be so affected by a few degrees difference of cold.

My next plan now is to try to insulate the battery to keep it warmer as an experiment.

Thoughts?

When the battery is cold, even if fully charged, the available current from it may be greatly reduced.

Also, in the cold, the charging system on a Leader 125 engine will struggle to charge the battery completely. If there are any accessories added (heated grips for instance) then it you're doomed to have to put a charger on it every day.

Add to that that if a battery has been fully discharged, it's life has been shortened - fully discharge more than a few times (and left for more than 24 hours in that state) and it'll need replacement.

On the other hand, cold per se isn't bad for a lead-acid battery, it's self-discharge is slowed right down - just don't use it if not fully charged.

If you park the bike on your own property then have something like an Optimate handy to attach every day. Fitting a 12V 'ciggie lighter' socket to the left-hand 'knee cover' works well for this.