Checking for spark on 1978 Bravo

I have sorted out the variator issues and am trying to check for spark by cranking with a drill -- so far with no success. I have no idea of the sequence, and want to make sure I am doing the "simple" things right. I know I will have to pull the engine someday, but the bike is so clean that I believe I may just be forgetting something easy.

1). The ignition should be turned clockwise all the way, correct? What is the middle position for? My Bravo (EEV1) has blinkers powered by a separate battery. I have checked the bulbs in the tail light and they are both good.

2). The kill switch (right thumb) must be "on".

3). .....do any brake pedals need to be depressed? Does the throttle have to be open wide to check for spark?

Are there tests you do across the terminals (pictured) to check for continuity? I have read the coil is seldomly bad.

I hate to be a doofus, but I don't want to look back in a week and kick myself for not trying the simple things. Thanks everyone.

IMG_4477-1.JPG

Re: Checking for spark on 1978 Bravo

You wanna make sure you turn the right direction. And that the kill switch is on run. Take out the plug, still in the boot, lay it on the engine so the metal is in contact with metal. Spin the flywheel with the drill. You can remove the belt so it's not trying to spin the rear wheel while ya check. If no spark, try prying the little cover off the ignition so you can reach in and 1st make sure the points open at the right timing, and if that's good, but no spark - clean the points

Details of the how to, read thru Fred's guide in the wiki

Re: Checking for spark on 1978 Bravo

your bravo specific issues relating to no spark has been covered recently in repair, use search function on top. or just scroll down. suggestions:

1. learn how spark works, ext ig ground.

1a. clean reclean points

2. ground blue.

2a. it does spin cw

3. fix grounded wire to tail light hidden in rear fender bead.

Re: Checking for spark on 1978 Bravo

I was turning the engine clockwise -- so that's good. I do not think I can get to the points without taking the engine out. I had the spark plug out and grounded it in several different spots with the Little Lady running the drill -- still no spark. There is only 414 miles on it, so I was hoping the points and condenser were good, but it may be quicker to take the engine out and test it on a bench (there is a you Tube video). Apparently that is something I will have to learn to do at some point anyways, so maybe just surrender and pull the engine. Thanks WillD.

IMG_4499.JPG

Re: Checking for spark on 1978 Bravo

Pat; thanks for the tips. I had just checked the bulbs for continuity, so I will now check the ground wire. I think for the points and condenser I have to yank the engine. I posted a picture above. I believe all the info I am looking for is buried in the Forum somewhere, it is just sifting through everything gets a bit much. I appreciate all your guidance.

Re: Checking for spark on 1978 Bravo

So you are aware, as Pat tried to explain, the wires that feed the taillight run thru a rolled bead along the edge of the rear fender. It breaks and shorts out eventually at some point on EVERY bravo. When this happens, you will lose spark. This may not be your current issue, but if it's not now it will be at some point. It is really important that you understand how these silly Vespas get the ignition ground thru the brake light. There is tons of info on these electrical systems on this site, if you get good with the search function.

Re: Checking for spark on 1978 Bravo

I’ve had a few random no spark issues on the multiple Vespas I’ve had.

On one of them the wire in the kill switch was pulled off of the terminal and grounding out on the handle bars.

Another had corrosion in the spark plug wire where it screws onto the coil and at the spark plug boot.

I’ve also had a engine that had a break inside the wire coming off the ignition coil not sending power to the ht coil.

I had another engine that the return spring on the points broke and was grounding itself on the points cam.

I’m not saying any of these are your issue just a few things I found in picking up non running Vespas.

« Go to Topic — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account