T5 not starting

Hi chaps my friend has bought a T5 mk2 and he is having a bit of hassle with it it just will not kick over it needs the spark plug heating over aflame before it will start then its ok for the rest of the day but if you just try to kick it you could try all day for nowt [:rolleyes:] [:rolleyes:]

Hey Dirk,
Jumping on grahams wagon a bit but my PX 200 is only 3-4 weeks old and has always flooded if the fuel tap is on. Should the dealer be doing this float needle replacement under warranty or is it not worth the hassle so I should do it myself…

Cheers [:bounce:]

Speaking of which I have just had to send my new(600miles) 24si T5 carb to the supplier as one of the blanking(i think thats what theyr’e called)balls had dropped from its position ergo my scoot wont tick over.I tried tapping it back in once but got a hefty 20 miles before it fell out again.I have never heard of this happening before whats the view on this?? have we hit a dodgy batch of dellortos or are we all just unlucky??:shoot1:[:dance3:]

Hi bod when it is kicked a few times and doesnt start the plug is removed and it seems oily dont know if this is just exess petrol or what but the timing seems ok because it can tick over for ever once started ?[:lickout:] [:lickout:] [:lickout:] [:lickout:] [:lickout:] [:shock1:] [:shock1:] [:shock1:] [:shock1:] [:shock1:] [:shock1:] [:shock2:]

[:D] Just confirming what bodichi has said, I had exactly the same problem with my new PX200 and was about to take it in to the dealer to get the bloody thing fixed when my brother suggested turning the fuel tap off after riding it. Three of his previous Vespas could be left with the tap on but on two of them he found he had to turn it off or else it would not start the next morning, weird…
Mine was an absolute bastard to start before but now its on the button every bloody time.
Hope this solves your problem too,

[:bounce:] Good luck…!

i dont think this problem is to do with float needles it seems to be a problem common to vespas and lambrettas with standard carbs as they both have very small float chambers. Leaving the fuel tap on dosn’t seem to be a problem with 28-30mm carbs [:rolleyes:]

Sounds like it needs a new float needle. This will stop it flooding and will mean that you can leave the fuel on. They are cheap and easy to replace.


If your float needle is not seating properly you should should get a few drips of petrol out of the carb overflow when the petrol tap is left on. Try parking on some clean tarmac over night with the tap on and see if there is any leaks in the morning. I had to replace my float needle after 15000 miles, it was visibly defective and had worn a circle at the top on the plastic/rubber tip.

check ignition timing and jet sizes in carb. Also check plug after riding a few miles, if it wet or oily it means jetting is too rich which will make starting difficult.

Back to the original question i had a brand new T5 Mk. 1 that wouldn’t start in the rain .Turned out that it needed a grade hotter spark plug.Put one in & problem solved.Apparently it had been set up for a warmer climate!

My new Vespa PX200 (my first one) which I have had for approx 3 weeks was a poor starter from cold. It started but it took a few turns of the starter motor which I found disappointing considering it was new.

Anyway at 1000km I gave it a service etc and changed the spark plug. The original was a Champion (a make for some reason I have never liked) and I replaced it with a NGK. The starting is much improved. Perhaps the grade is different I don’t know.

Incidently I have had no problems with flooding and I leave the fuel tap on every night.

Cheers, Andy.

[:roll:] [:roll:] [:roll:]

Sparkplugs can be funny things, I’ve been using Denso B9 Platinum plugs with no trouble at all, but my scoot doesn’t run very well with the standard Denso B9 plug. [:rotate:]

I would take it back. This just shouldn’t happen to a new bike. It could be that there is manufacturing fault with the carb. i.e the seat that the needle seals against could be imperfect or set in the wrong position even (fairly unlikely, but you never know)…unless you just can’t bare to be apart [:D] or you live miles away…in which case a jet probably only costs a couple of quid (or euros or dollars)…and really is easy to change yourself. If you want to do this I can explain the procedure…just let me know[:dance3:]

i would check main and choke jet sizes it sounds like they are too big , also always turn petrol tap off when not running dont forget its gravity feed and can cause engine to flood[:roll:]