Vespa Bravo has spark won't start

Hi folks my vespa bravo has spark but won't start.... I don't have a bulb in the rear tail light so that may be the problem it has fuel in the tank so I don't know what the issue may be .

Re: Vespa Bravo has spark won't start

Put a brake light bulb in, then check back.

Re: Vespa Bravo has spark won't start

Here's my chain maybe I am missing something

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Re: Vespa Bravo has spark won't start

Heres a diffent pic

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Re: Vespa Bravo has spark won't start

Does this need to be pushed down to start I don't have the chain guard ?

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Re: Vespa Bravo has spark won't start

normally outta that rubber gromet theres a blue n a black. blue needs to be grounded for spark, black goes to coil. check out the wiring diagram in the wiki. some switched out your blue for....and added an ext. condenser.

Re: Vespa Bravo has spark won't start

oops u have spark. spray some premix in the plug hole and drill start, u did mix oil w the gas right?

Re: Vespa Bravo has spark won't start

I've been going over these pics, and I gotta ask a question. I see you're new to mopeds. How is your mechanical ability? Be honest. The reason I ask, is while a Vespa Bravo is relatively simple in it's design, they can be pretty quirky if you're not familiar with them. They have certain nuances, which you will discover soon enough, that will frustrate you immensely, but once you solve them you will wonder why it was so difficult. These quirks and nuances are easily overcome by even a novice mechanic, if he has a clean slate, or a stock bike, to start from. You do not. Somebody scribbled all over your chalkboard. Your bike has been modified. These modifications will make your life hell while you try to troubleshoot a problem somebody else created.

In your first picture, I see several things. First, as Pat pointed out, someone installed an external condenser. I'm wondering if the original condenser under the flywheel was removed when this was done. Sometimes you can get away with leaving it in. Sometimes not. Best to delete the original when installing the external. Next is your variator. That's the front pulley thing that the belt goes around. It has that big nut in the middle. Yours is not stock. It's a performance upgrade. Improperly installed. See how the nut does not have full threads? Those particular variators are a little too thick overall, and a little has to be removed from the inside bushing. I had to remove about 2 mm from mine, but be careful not to remove so much that it rubs on the subframe. If you don't, you risk stripping the threads off the end of your crank. In other words, Your variator must be narrower so you can get a full nut of threads on the crank. Also, that washer under that nut MUST be bent up against a flat side of the nut to keep it from backing off. Bad things happen then.

In the second picture is another view of your externally mounted condenser (top left). I don't remember what that red wire connector on the case is for, lights? Someone will pipe in on that. It's been a minute since I messed with my electrical.

In the third picture is your rear variator, and start clutch assembly. See that yellow spring in there? That's your contra spring. Yours, once again, is aftermarket performance. The yellow spring is stiffer than stock. No problem if you have enough horsepower to compress it! Do you?

In the fourth picture, see that black button? Push it in to put the transmission in bike mode. This makes it so you can pedal around like a bicycle without engaging the engine starting system. Flip the little lever next to it to disengage.

In the last picture, that lever is your choke. Push it down to start when the engine is cold. Also in this pic I see that you have an aftermarket high flow air filter. Which means you probably have a bigger carburetor also. Maybe not. But should have, because you probably have an aftermarket exhaust, too. I can't see it. What I'm getting at, is there has been a whole bunch of stuff done to get this bike to the non running state that it is in, and it's gonna be a long row to hoe if you aren't mechanically inclined.

Re: Vespa Bravo has spark won't start

Just saw the pics of your bike in your first and second post... Yup, you got a pipe on it. Big ol sack hangin under it!

Do us a favor, take a pic of your cylinder and head. I'd like to see a good side view of the engine to see if it has a kit on it.(edited)

Re: Vespa Bravo has spark won't start

Yes I added a 2% mix with the gas

Re: Vespa Bravo has spark won't start

> Tom D Wrote:

> -------------------------------------------------------

> Yes I added a 2% mix with the gas

It's probably flooded. The choke lever is down and most times you don't need to even when cold. Once flooded it's a real pain to start. At least mine is.

Re: Vespa Bravo has spark won't start

> pat splat Wrote:

> -------------------------------------------------------

> oops u have spark. spray some premix in the plug hole and drill start, u

> did mix oil w the gas right?

This^^ take starter clutch slipping and belt slipping out of the equation. Try to drill start it.

Re: Vespa Bravo has spark won't start

Here's some pictures of the cylinder..

> Seth B Wrote:

> -------------------------------------------------------

> Just saw the pics of your bike in your first and second post... Yup, you

> got a pipe on it. Big ol sack hangin under it!

>

> Do us a favor, take a pic of your cylinder and head. I'd like to see a

> good side view of the engine to see if it has a kit on it.

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Re: Vespa Bravo has spark won't start

Yeah, you've got a kit on it, too. It will be a great performance bike, if the mods are done properly. It shouldreally rip! That is, if you can get it to go. It looks like it's wired for spark, and maybe deleted the tail light. Hard to tell.

Re: Vespa Bravo has spark won't start

Oy.... The light bulb thing.....for crying out loud. The bulb thing is not right. A broken bulb, or a missing bulb won't prevent spark UNLESS YOU ARE PULLING THE BRAKE. But who pulls the brake when they're trying to find spark? Nobody.

LOL Get it together, Vespa guys!

Other than that, good job.

At the OP, if it has spark, you need to check strength. It has to have powerful spark in order to run. It looks like you have an old HT (external) coil. It might be that that is bad. They go bad often enough. An adjustable gap spark tester is the tool for the job. You need the spark to jump a good cm or half inch to be strong enough. I had a Bravo that had spark, but I didn't realize it was too weak. I spent 6 months checking and fixing every single thing . In fact, even the HT coil was new.

Unfortunately, you are not starting from scratch. If you had all those mods and it ran, that would be great. But since it doesn't, and you have no way of knowing what was actually done to that engine, you can't count on anything.

So, you need to start with the assumption that every single part is bad and needs repair or replaced. You need to systematically overhaul and/or clean/test every part of the system. I'd look up Fred's guide in the Wiki and start there. Also, google "Vespa Bravo Haynes" and download the repair manual. Even with aftermarket parts, it will help you refurbish your bike.

If you have solid, strong spark, then it can only be fuel (clean the carb, use a filter with new fuel line, and clean the petcock) or air. Air includes air leaks and bad compression. I have a friend who's Ciao engine was perfectly sealed, and it ran fine as long as you were on the throttle, but died every time he stopped. Bad decomp leaked so bad he didn't have good compression. Air leaks are usually from a bad crank seal or at the carb.

But, that is what I assume when I deal with stock bikes for the first time. With a modded bike, there are absolutely no guarantees about anything. Assume it is bad until you prove it is good. It is the only way. Unless you get lucky. And I never do. LOL

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