DNA 125 MOPED

[justanotherdude]

Hi there guys, am new to this forum, so apologies if its in the wrong place ive posted this!

I had a dna 125 and some div decided to reverse into the back of it, in anycase insurance paid out and i bought a new one off ebay last week.

So i set out on a 40 mile journey to collect the bike, give the dude the cash and leave the bike running while im counting the money. It runs fine. I then ride off and for the first mile and a half it was nice and smooth, but i could smell burning, smelt like paint burning... (he had resprayed the exhaust!!)

In any case all the service etc was in order and MOT has only been passed a week ago, a mile and a half in i got stranded as i breaked the bike cut out on me completely when i revved it.

So i pulled over switched the bike off and restarted it again, it was fine running again, however when i took it off the stand it switched off again. I started it again, it wouldnt start just merely kept trying to, eventually it did and when i revved it, the engine cut out again!!! So i got off and noticed some sort of oily fluid leaking from the centre bit under the helmet storage tank was leaking this fluid. From what a mate says he believes its gearbox fluid, but i have no idea.

My concern is if i kept teasing the throttle the bike would switch on, however eeerytime i breaked it cut out on me again.

I have no idea whats wrong with it, the sellers f'd me off by being useless!

I had to wait three hours for a mate to come up with a van so i could take the damn thing back to london. However while i was waiting i tried to start it up again, and the rear wheel seems to be going in reverse!!! AHH

I dont know whats wrong with it as being a previous dna owner for a year and a half i never had this problem, i had it cut out on me on dual carriageways but that was a fuel injection problem which i sorted.

Anyone with any ideas?? Would really appreciate any ideas as to what could be wrong..

So to summarize... Bike starts and when stationary is fine, any gentle tug of the throttle the bike either cuts out or the back wheel spins in reverse...

And there is a leak of some sort, believe gearbox fluid...

Thanks guys!!

[Pigeon]

Sounds like fuel starvation... check the carb for blocked jets, check the fuel supply to the carb is working... if it has one of those shitty vacuum-controlled fuel valves try setting it to "prime" and see if that helps.

The fluid leak is unlikely to be anything to do with it.

The running backwards thing is just one of those things two-strokes do sometimes, especially when they're not running well

[justanotherdude]

Pigeon said:

Sounds like fuel starvation... check the carb for blocked jets, check the fuel supply to the carb is working... if it has one of those shitty vacuum-controlled fuel valves try setting it to "prime" and see if that helps. The fluid leak is unlikely to be anything to do with it. The running backwards thing is just one of those things two-strokes do sometimes, especially when they're not running well

thanks for your reply. its actually a four stroke, dont know if that makes a difference? Also how do i check the carbs for blocked jets? being honest im not that experience with mechanics on mopeds, so would appreciate a bit of advice...

i just want the bike back on the road, as i have no transport i hope its an easy fix. i had a dna 125 before and the fuel starvation problem happened on that too, but it wasnt as bad as what is happening to this dna!

[Pigeon]

If it's a four-stroke I must say I'm baffled as to how it can run backwards. You might persuade a diesel four-stroke to run backwards, but not a petrol one.

As to checking blocked jets... take the carb off, take the float bowl off, that will usually reveal the bottom ends of the jets, you can then unscrew / look through / blow through them to check they're clear. Don't stick bits of wire down them to clean them, but semi-rigid cellulose/lignin or keratin fibres (non-synthetic bristles off a broom) are soft enough not to do any damage. Best to get the Haynes manual though because carbs differ. And while you're at it, check that the needle valve flows freely but shuts off with the float at the correct height.