Ducati Sporting Club UK > General > Idle Chat > Anyone Know About Mini-Moto Engines?

[Ian Harris]

One of the kids next door to me has a mini-moto which he is trying to start up for the first time in several months.

It doesn't seem to be catching at all, so I took the spark plug out and cleaned it, but there didn't seem to be a spark when I turned it over with the spark plug out.

Do these things have a little dynamo that provides the necessary current? Or is there a little battery somewhere (ht lead seems to go into the crank-case cover, and I didn't want to start dismantling it, particularly as I'm trying to get some poxy ill-fitting track bodywork drilled ready for a track-day)

If anyone has any ideas what the problem might be, suggestions would be much appreciated.

[Scooter916]

Mate if its a chineese copy most certainly the cdi is buggered, Its very common and they are available on flea bay.
Glyn

[raykay748R]

What make?? Chinese are notoriously unreliable (cheap) but plenty of spares around.
No batteries I'm afraid, all magneto (l/h side), could be cdi, lead , cap, plug, earth etc,etc,etc.
Any help?

[Ian Harris]

Glyn, RayKay....Many thanks for the answers, it is as cheap and Chinese as a cheap Chinese thing, so I reckon the buggered cdi is a fair bet. I've found a store that sells them on ebay, so I'll get the make and model and send off for one.

Cheers,

Ian

[Edited on 19-3-2006 by Ian Harris]

[rcgbob44]

Shoot the kid and dump the bike, there a curse on society!

[Ian Harris]

I've fitted a new CDI to the mini-moto, and its still not firing, there's definitely a spark, but I'm not sure if any fuels getting through (that's the only other thing I can think of that would stop it "coughing" at the very least.

Also, after turning it over for some time, there seems to be a slight case of hydraulic lock Any ideas what's going on? My non-existent knowledge of two stroke engines is now totally exhausted.

[Spen]

How good is the spark?? If it's a dodgy spark plug it might be that the spark is being snuffed out under compression. Try another spark plug.

If you can't get it started with a change of plug, get back to me and I'll run you thru' procedures required in checking for 2 stroke problems.

[Ian Harris]

Thanks Spen, spark looked pretty good, and definitely felt quite strong when I applied the "turn over engine with fingers in vicinity of electrodes" technique.

I'm off to Jerez tomorrow, so won't be able to try anything else until next week. I'll ask the owner to get a new spark plug and, if you don't mind, I might pick your brains next week. My main worry was that the feeling of hydraulic lock might be a problem.

[Spen]

Check the plug is getting fuel on it. If not, ensure the jets are clear. If they're clear, you could be looking at a 'negative pressure' in the motor. An air leak in a crank seal can cause this and stop the fuel being drawn in. Two strokes are great when they're running properly........ I can't see it being hydraulic lock, unless the carb' has leaked SO much fuel into the crankcases.... it would lock up, not just feel stiff.

Make sure you change the spark plug first though. Any problems, ring me on 07810 866456.

[Edited on 22-4-2006 by Spen]

[Nattyboy]

U2U Duke2bsteve..his mate runs a mini moto track and is very handy with them. When you do get it running..dithc the cheap spark plug and get a champion or equivalent from your local lawnmower shop - makes an BIG difference in terms of ease of starting and performance..

Mine doesnt start now eithere but I put it down to the crabs being gummed up..just havent had the time to do anything about it ! Let us know how you get on !!

Nat

[Edited on 23-4-2006 by Nattyboy]