Vespa grande won't start

I rode my grande for about an hour yesterday and let it sit for a few hours. I went to start it and it won't start, it has been taking longer to start lately and now nothing. Thanks in advance for your help.

Re: Vespa grande won't start

I had the same problem when I first got my Grande. As soon as I shut it off, it seemed like I had to wait longer and longer to get it going again. Try removing the cylinder head and taking a wire brush or light abrasive pad along with some carb cleaner and clean the carbon off of the piston and the inside of the cylinder head. Hopefully it should start up much easier the second time around.

Re: Vespa grande won't start

Check the state of the breaker points. If they are burnt in, the condensor probably died, which results in burnt points, which then results in no starting.

grz Thijs

Re: Vespa grande won't start

Mark, does it have spark? there are a whole list of things that will cause a no start condition.

Spark and the condition of the spark plug are the first things to check.

let us know and we will help you keep that Grande on the road where it belongs.

Re: Vespa grande won't start

Dirty Plug? Carb clog?

Re: Vespa grande won't start

Who has a favorite spark plug and gap measurement for a Grande? Just picked up a sweet '79 in great (visable) condition.

Haven't had a chance to turn it over yet. Sopposedly, it has no spark, but the seller didn't realize that the "little hood ornament" was the key. I'm hoping he had it in the wrong position when he was testing it out.

I've been told the points are difficult to get at. That the engine might have to be dropped. Do I have to remove the variator, the rear wheel, and that plate to get in there?

Is there a way to make sure that the key being in the correct position is doing what it should be, and same thing with the kill switch, so that I can check these things before I dig deeper into the bike?

Thanks for anything you've got...

:Mitch

Re: Vespa grande won't start

Mitch, check it out yourself and see if it has spark or not. There are a few things that will cause a no run, no spark is just one of them.

Does it have the handle bar switch or a key switch{on the speedo}? either should be labeled run/off. do you have any pics?

If it does not have spark you want to make sure the points are bad before replacing them. Yes the engine has to come off to replace them.

You can remove the rubber piece that is on the flywheel to inspect the points. You can check the gap and maybe even file them a little with a point file.

Its not hard to replace them just a little time consuming. If you are not familiar with it do your home work first.

To replace them you remove the belt and the variator, the air filter and carb,dissconnect wires{be careful these old brittle wires have a habit of breaking}

Then remove the long bolts and the one short bolt and swing it down and out. Its highly recommended to use a flywheel puller to remove the flywheel but it can be done without one using extreme caution and common sense.

You can get the points and puller from Zippy{ I am sure he is lurking on this forum some where}

http://www.zippymoped.homestead.com/

You can also go to the repair section of this website

http://www.mopedriders.org/

and look at some of the repair manuals they have . There is also a link to a cio bravo haynes manual{very good manual} on this site some where . You may have to use the search to find it.

Hope this helps.................

Re: Vespa grande won't start

thanks. i was wondering about that little rubber peice, didn 't want to pull it off and find out i shouldn't have.

it definitely doesn't spark. the handlebar switch looks fine inside, and all of the wiring everywhere on the bike seems ok. the key mechanism also looks pretty good. maybe i'lll go and try to get into those points and see what they look like. i really don't want to have to pull off the engine, but if that's what it takes...

having a bad bike night. can't get my girlfriend's suzuki to run either.

:M

Re: Vespa grande won't start

Switch on top of the headlight should be a 3 position, 11, 12 and 1 o clock. Switch should pushed down in the 11 o clock position to make sure it is engaged and then turned to either 12 or 1 o Clock. Right handel bar Run switch must also be ON or RUN.

Pull the center engine cover and make sure the two ground wires on the top left (red) and the Top right side of engine (black or blue) are plugged in for ground. The right side is a little bit under the fuel petcock. This one (right side) is your ignition ground.

Also check the wires going into the back of the coil.

Screw off the spark plug cap and snip the tip off the spark plug wire to get a clean connection and then screw cap back on. Look up inside the cap and check for a clean contact.

Put in a new plug NGK B5HS or B6HS gapped at .020"

Re: Vespa grande won't start

Thanks Zippy. Checked all of this out and it seems ok. My understanding of electrical systems is nil. A friend check connections with me using a voltage meter, and says that when he took readings at the kill switch and key switch he was getting a ground reading at all settings (on/off, key pos. 1,2,3). Not sure if this is as it should be or not.

All of the wires on the bike seem intact, and there's no indication that there's been any corrosion anywhere besides where the front signal stem broke from the headlight casing (we snipped the signal wire there and remved the whole signal unit and stem).

We took a reading from the spark plug wire while i pedaled and got a small amount of voltage. So I'm guessing that it is the magneto after all, and i'll have to get in there. I cleaned the points, but that didn't help. What am I looking for once I get inside? Will it be something obvious? Any help appreciated. Thanks!

:K

Re: Vespa grande won't start

If you have spark, try removing the spark plug (you are using a new one, correct?) and squirt starter fluid in the spark plug hole, then replace the plug and try starting it again. If it starts or tries to start, then you have a fuel flow problem and need to remove and clean the carb, check the fuel flow at the petcock, etc....

Re: Vespa grande won't start

Unfortunately, that's the main problem right now. New plug, but no spark. Once I get it sparking I'll mess with the fuel system, which is really the only part of the bike I'm familiar enough with that I know I can fix if theres an issue (at some point I'll need a carb gasket, it appears to be leaking. and a drive belt, natch.).

So, a friend checked connections with me using a voltage meter, and says that when he took readings (with the bike not running) at the kill switch and key switch he was getting a ground reading at all settings (on,off and key pos. 1,2,3). Is this bad? Or should is this the way it should be?

:M

Re: Vespa grande won't start

Bruce Wilkinson /

My Ciao had no spark. I took the engine out and flywheel off ( you may need to buy a puller from Zippy ) and found that a wire on the secondary coil was bad. The wires are tight under the flywheel and one can touch the cam and get worn through like mine did.I soldered the wire back together and made sure it was away from the cam. It's a bit of work to take the engine out and I would put new points and condencer and oil seal in while it's all apart. Parts from Zippy.

Re: Vespa grande won't start

Bruce Wilkinson /

The carb can leak from 3 or 4 places. If you tighten the banjo too tight the threads on the carb body strip and it's hard to fix. I've ruined a couple of carbs this way. Do NOT over tighten this banjo bolt.Look closely to see exactly where the leak is. Make sure it's not at the petcock and running down the gas line to the carb. A gasket set is available as a package from Zippy.

Re: Vespa grande won't start

Thanks Bruce.

I haven't even looked at the fuel system at all yet. Want to get it sparking before I invest time in anything else. It just appears to be leaking from the seal... will investigate in the future. It's not so bad that it's dripping, it just looks wet. Thanks for your advice on the banjo bolt.

I'm resigned to having to take the motor out and get into the flywheel. Hopefully the flywheel puller I have for my Moby will work (anyone know?). So I don't have to buy anything or wait for it to show up.

Anyone have any thoughts on the electrical situation in my last post? The guy that was helping me knows some engineering stuff, but nothing about bikes, so it's possible he had no idea what he was doing either.

:K

Re: Vespa grande won't start

I stripped out my carb like that too :(

Re: Vespa grande won't SPARK

So the bike in question is all kinds of spotless. All wires and connections are super clean. The only two visable problems are the broken horn switch (just the plastic part of it is snapped), and the 'lever housing' on the throttle side is a little broken, so the break light switch is not screwed in anymore. However, these breakages don't appear to effect the connections at all.

Here's the big new clue (possibly): When I pedal the bike to start it, even though I still get no spark, the horn is always sounding! So that would make it seem that the magneto is working smoothly, if it's powering the horn. The center stand rusted and broke off (wait, that's the third visisble issue) before I could spend more time exploring this selective electricity thing, so now I can't pedal it until I get a new one or rig something up.

Does this mean anything to anybody?

Thanks!

:M

Re: Vespa grande won't SPARK

i wonder if... nah it couldn't be....

do you think that all the electrical is wired through the horn?

i've known a few bikes now to run strange electrical... i had a bike that relayed everything through a turn signal. i re-wired that entrie bike, and of course, the last thing i replaced... the left signal, happened to complete the circuit and grounded the entire electrical system.

i had a suzuki fa50 that was re-wired by some tweeker, and the horn doubled as a ground. just a long shot i guess, but wouldn't that be nice. it would explain why the horn is constantly sounding... could be grounding out due to shotty wiring? just a thought.

Re: Vespa grande won't SPARK

hm. that's crazy. i'll see if any of my friends that actually understands electrical shit buys it. maybe someone out there that knows grandes can fill me in.

i had forgotten to mention, there was some corrosion in the wiring. the left turn signal wire was rotting out, and the stem was hanging off of the frame, so i just clipped the signal wire short where it leaves the headlight housing.

:K

Re: Vespa grande won't SPARK

I have been trying to follow this thread and am having some difficulty, but would like to offer the following fact.

Keep in mind, the Piaggio Vespas Grandes, like the Si, Bravo, and Ciao, as well, I think, will not run, ie, no spark, if the brake light is not working. This is by design. You said the brake light circuit is disabled. That circuit will need to be connected and brake light working before you will get a spark.

Zippy can further elaborate on what you may need to do.

SPAAAAAAAAAARK!!!!

Thanks everyone for all of your ideas!! Even the ones that weren't right helped me learn a lot about the bike. Frankman wins it with brakelight issue.

I looked at the bulb, and it was blown. So I replaced that, then realized that with my rusted-in-half center stand I wasn't going to be able to test anything out. So I stole the center stand offa my Bravo, made the switch, and pedaled up. No dice. Then I remembered the switch that had come out of its housing behind the break lever, so I grabbed that, pushed down, and with about a quarter turn of the pedal saw a nice huge bright spark firing away!

Thanks again everyone for answering all of my questions! Without the moped Army I'd be pedaling everywhere, if that.

:Mitch

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