Cutting out in 4th gear - 30mph

[antvespa]

Taken out my VBB150 for its first run down after a 3 year restoration (slow I know).

Took it out a few times and seemed ok but today went for a longer drive but only got about 3/4 mile down the road and it cut out in 4th gear! Try to give it more revs but nothing and it just died on me.

Has a Pinasco 177 cylinder head, 20:20 carb and a SIP road 2 Exhaust.

Any ideas? Is it not getting enough fuel or too much when in 4th? I admit I Don't know the jetting just what came with the carb!

Could it be a soft Seize? Didn't feel like the back wheel locked up at any point just the revs dropped and the engine died

[mijapxman]

You really should check your carb jetting, Bud and let us know what jetting you have?

Have you had the engine running, since this happened?

Take it you mean it has a 177 cylinder AND head fitted, did you fit this?

Did you rebuild the engine when you restored the scoot?

Did you fit a new fuel tap?

Did you clean the fuel tank? Was it rusty inside?

Did you renew the wiring loom?

How does the compression feel when you use the kickstart? Does it feel like it needs the same amount of force on the kickstart to turn the engine?

Reason for these questions is to try and ascertain if you've seized the rings to the piston OR holed the piston OR it's an electrical problem OR it's a fuel tap problem.

Mij☺

[ironsloth]

What's the jet size in your carb?

[antvespa]

Checked the carb today and the jets are as follows 48:160 and 112.

The engine was rebuilt with all new seals bearings, new Marzucchi (spelling) crank and the work was done by Atoms in Maidstone, very reputable garage for Vespas down south.

They never had it running as I was sourcing a clutch when they were working on it and was over a year ago due to a long restoration.

Fuel tank is new as old was unsalvageable and the fuel tap is a new SIP fast flow one.

Today I took it out and it kept stalling at idle - managed to get it home but only keeping the throttle open!

So it seems the opposite of yesterday but it kept hesitating both days as if it wasn’t getting a rough fuel at any point.

[antvespa]

Also the wiring has just been renewed and seems to working well so I don’t think that’s the issue.

Kickstarting seems ok and doesn’t take more than 1-3 kicks at the most to get it going.

Compressions wise I’m no expert so I wouldn’t know what is good or bad

[antvespa]

This may be a stupid question but could it be old Fuel with potentially too much oil in the mix that are causing issues??

[jackthekipper]

if its never been tested..it could be something simple as adjusting the mixture or air screw on the carb

[antvespa]

I'm hoping so - Did realise I filled it up with fuel that was over a year, I old grabbed the wrong Jerry can so my fault.

[ironsloth]

That could well be it. Drain the tank, mix up either super unleaded with your two stroke, or normal petrol with this:-

rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F283439830667

[antvespa]

Tried new fuel - It still bogs down at low revs and the engine just dies when idling! Have to twist the throttle a bit to keep it going and this is with the choke out.

Seems fine in 4th now with loads of throttle - when it sounds the healthiest!

[ironsloth]

Did you flush the carb or just dump it in?

[antvespa]

How do I flush the carb?
Complete noob to a lot of this

[mijapxman]

Because your a noob and Atoms( who have a very good reputation, as far as I know) build the engine, I would ask them to take a look at it, especially as they never run it.

Mij☺

[scooterg]

Well said mij, so they should,you paid the piper

[antvespa]

Managed to get it to idle well this evening, mixture of new fuel tube cut to 24 inches, clean out the carb float, jets. Mixture screws etc and fiddled with the choke that kept coming loose!

Then the throttle cable had come loose so tightened that up.

Least I got it to idle so tomorrow night I’ll take it back out for a spin to see how it runs.

[scooterg]

And now you walking with your head held high
Saying to yourself,,(every time you look at the scoot) I FIXED THAT

[antvespa]

Haha I will wait until the ride tonight......

[antvespa]

Short lived excitement as tonight I can’t even get the bike to kick start.

Losing my enthusiasm and confidence in it all now

[scooterg]

Now you look at it and say *&£&*&£#

[antvespa]

Took a look at the spark plug and it was coated in oil - taking that as a bad sign

[mijapxman]

Turn the mixture screw at the back of the carb right in,( clockwise) then turn it 2 full turns out, (anti clockwise), ( all this 1 1/2 turns on a spaco /Dellorto oil pump carb or 2  1/2 turns on a Dellorto is not accurate, imho 😉, as all engines are different) this should be enough to try starting it ,after you do this 👇


Don't worry about the spark plug at the moment, clean it and while it's out, with the fuel tap closed, kick the scooter ,10 times ish, to clear the cylinder of fuel, replace the spark plug, turn on the fuel and ignition an try starting the engine, it may take a few kicks .

Let us know if it starts and revs.

One thing I am concerned about is your ignition timing, as Atoms can't have set it properly, because they haven't had the chance to run the engine, this is very important, especially as you said they fitted a new crank.. See here for how fitting a new crank can change ignition timing 👇



If it starts don't be tempted to take it for a run at the moment, get back to us and let us know if it started.

I really recommend you getting Atoms to have a look at it and get it started, as they built the engine and can set the timing and carb up.

I'm in the middle of splitting my mates p200 engine, with it still in the frame as his clutch side oil seal has blown, only came in for a drink, before I get sunstroke 😂😂 and thought I'd have a little look at the forum, lol.😂😂😂. That's me going back out to top up my sunstroke now 😱😚.



Mij☺

[mijapxman]

That's me in for another Pepsi break, just got the 4 nuts to remove from the studs under where the stator plate was and I can split the cases and see what the story is with this clutch side crank seal. My backs getting sore now though, more painkillers and a bit of stretching will hopefully help a bit, or my mate will be well p*shed off, if I leave it as it is, outside in my back garden!😂😂😂.

Mij😉

[antvespa]

So got my Mechanic to take a look - he is called Vespaman based out of Wimbledon vespaman.co.uk and can't recommend him enough

He put on a new 6v stator a while ago as the 12v kit I brought and I made Atoms install was basically garbage - My fault really.

So he set the timing and got it working for me when he finished up a few final jobs so I'm under the impression that its all ok.

What we did discover though was that the fuel hose was just too long by around 10cm so it was restricting the fuel into the carb a lot which is sort of what I felt all along. Shortened that and cleaned out the jets and it runs as good as ever.
He said I could potentially go to a 55/160 as I'm only running a 48/160 at the moment so I've got one of those coming and also down jet to a 105 or 108 but as its running ok at the moment to wait, do some more miles and check the plug regularly etc as I'm still running in the new cylinder and rings.

[mijapxman]

Some cheap prices from vespaman there, I know a guy that got charged £85 for getting a new clutch inner cable fitted by a garage in Kirkcaldy Fife Scotland, think they were a lawnmower repair place that said they had or were getting a Vespa franchise!!! That happened 15 years ago!

Mij 😱

[antvespa]

Thought I had fixed it but after a good 10-15 mile run tonight the bike started to lose power again and cut out in the higher gears.

Seemed to run ok on Saturday but tonight not so much and again struggled to tick over on idle without giving it some throttle.

My 55-160 jet came so I’ll try that to see if it helps otherwise I’m out of ideas.

[shovel1]

Hello fella I’m by no means a mechanic or expert hence why when having an issue I turn to the guys on here (they act and direct on all the info you send if there’s one thing that lets this site down it’s the ability to up load a video of your issue, admin hopefully you can look into this 🤞🏼🤞🏼🤞🏼)
From my tales of issue and woe (see previous posts) I would suggest a) if premixing don’t mix 3% MIX 2%, b) even though you’ve a new parts and fast flow etc the scooter can only manage the petrol it runs on ie you could be over fuelling so look at smaller jetting, c) trial and error carry your jets etc on you and try find an area close to your home where you can just keep testing and running up and down the road it’s the only way unless you have a dyno, this along with info from the chaps on here sorted my recent issues from what you’ve said regards jetting, I would look to start with a 98 jet, I went up and down jets thinking I need more fuel but it was often more than what the engine can deal with so I started with a 98 playing with the mixture screw and always running a little rich ie 1.5-1.75 turns out (this is just a guide you may find you need a little leaner between 1-1.5 each scooter is different) on the mixture screw, get it running well then once confident it’s seems like it’s running well/consistently go for a little longer run to do a plug chop to check plug colour (all these will give/gain experience and confidence for the future, good luck and in the meantime site managers please have a look at an easier way to upload our pictures and videos 🙏🏼🙏🏼🤞🏼🤞🏼👌🏼👌🏼🙌🏼🙌🏼🛵 🛵 🛵🛵🛵🛵🛵🛵🛵🛵