I have an 04 300 Pro. I was out last night and all of a sudden the bike died on me. I kicked it back to life easily but it ran for about a second and then died again. (I know what your thinking, fuel right?) Well I had plent of fuel so it wasn't that. It did sound like a fuel problem as every time I started it it ran for about a second then died again. This happened probably five time but on the sixth attempt it wouldn't start at all.

I pushed the bike home (mostly down hill luckily) and put it away for the night. Tonight I've fully stripped and cleaned the carb and replaced the plug. It again started once but died after about a second again and wouldn't restart for a good half hour when it did the same again.

When it's not starting there it no spark at all but after leaving it for about an hour the spark comes back. Screw the plug back in and away it goes for another second.

Now I'm starting to think the CDI unit could be breaking down (electrically) after it gets a good squirt of juice from the running motor. I can't make it break down with just kicking. It has to run before it dies completely again.

Has anyone seen this sort of thing before? If so what was the cure.

Does anyone know of a set of tests to check the CDI unit?

Jim Snell has a good wee bit giving the resistance of all the parts on an earlier model but I can't find anything on the 04 PRO.

BTW The bike has a Ducati ignition system.

Bigfoot, I haven't the foggiest what the CDI characteristics are when they go belly up but a coil breaking down manifests itself as a misfire at higher rpms.

Silly suggestion, your air filters not blocked is it (not likely in your part of the world)? Rag in the airbox (don't laugh it's happened to me and most of my mates)? Sounds like something like that.

Not much help I'm afraid.

First thing to do is change the spark plug.

I had a ty175 which ran fine then died so i checked it was still getting a spark which it was then tried again .

It would fire up then just die.

So i changed the plug and it ran a treat again.

Sometimes these wierd things happen

Let us know what the problem was once you have sorted it please m8 but give the spark plug a try.

James

Toofasttim. Sorry not that. I've no spark at all after the bike runs for 1 sec. It takes an hour for any spark to return.

BigJohn. I check all that and the coil doesn't appear to be leaking and I've fully insulated it from the surroundings.

James. As I said I've tried the plug. I've changed it twice and no luck there.

Anyone else got any ideas. I would really like to check the CDI unit and coil as I think its in there that the problem is.

My 04 300 Pro did the same thing and the problem was the voltage regulator, the part with the big heat sink. The rubber-coated side had either gotten cut or cracked allowing water to get in and corrode it. It was quite a bit cheaper than the coil/cdi unit.

Brockway

You be on to something. I inspected the regulator rubber encapsulation and it looks like water may be getting past the side where the rubber contacts the heat sink (it should be almost vulcanised on the sides but its not. ) I've ordered a regulator and CDI unit and the good folks at GGUK are going to take the CDi unit back if its still in its wrapping so hopefully the regulator change will work.

On reflection John, Brockways onto something there. If the sparks there briefly it's likely a "power problem".

I thought about this one for the better part of the day and drove Lynn nuts. But it's summat to with energy or the lack of...

Good for JST and Jude.

It was indeed the regulator. Changed it last night and it started first time and ran fine. Thanks everyone. I'll be returning the CDI unit to GG on monday.

Can i ask how much did it cost to fix then?

James

The regulator was

not to bad really then, just bugs you when you dont know what the problem is, you think its gonna cost loads but it doesnt in the end

James