Rieju RS2 50 Matrix 2003 WILL NOT START

[dolly3900]

Hi Y'all,

New to this place (and bikes), so this may have been discussed and resolved previously.

Got the above bike for my lad to pootle around on and gain some roadcraft ready for him getting a 125 next year, can't do any harm and it means I don't have to be a taxi all weekend

Problem is whilst he was practicing for his CBT last weekend (passed no problem), it stopped running and would not start.

Initially thought it had just run low on fuel as the reserve light was on to start with.

Put a fiver of Mr Shell's finest in and topped up the 2 stroke oil whilst I was at it.

Push the starter switch and it turns over lovely, turning the engine and all moving fine, but does not fire at all.

Tried bump starting down the drive (2nd gear and drop the clutch), which turns over the engine nicely, but still not starting.

After turning over for a while, you can smell the fuel and even see a few drops out of the exhaust, so it is obviously getting through.

I suspected the electrical system next and have removed the plug to check the spark only to find that when the plug is grounded against the frame, there is no spark.

AH HA!!!!! I thought, but by accident, my lad pressed the starter button whilst I was just removing the plug from the connection with the frame and there was a nice spark from the ground electrode of the plug to the frame.

Appears to me that the HT is entering the plug at the top and instead of going down the electrode, it is shorting out to the case of the plug and preventing the plug from sparking when in the top of the bore

My question is, is it common to have a plug fail in this way and is it going to be as simple as change the plug and away we go?

Sorry to prattle on, but the more info the better answer.

Cheers in advance.

Mike

[finpos]

Yes, sounds very much like you've ended up with a fouled plug - the problem is that there's enough oily carbon crud accumulated between the two electrodes that instead of jumping the gap and making a spark the electricity is discharging to earth through said crud.

Spark plugs self-clean by burning off the crud but when pootling about on a two stroke they often don't get hot enough to do that and thus lots of discussion about how hot a plug to use for town/open road use etc. How hot a plug is can be determined by it's number and it's accomplished by it's shape which means more or less heat is sunk into the cylinder head.

Easiest thing is a new plug, or if you are tight try to burn of the crud yourself with a blow-torch/gas cooker. Don't waste your time trying to wipe it clean.

f.

[dolly3900]

Many thanks for that, I suspected as much after I realised that the business end of the plug was rather cruddy.

Having done a lot with 4 stroke and Diesel cars, but nothing with 2 stroke I just needed a little reasurance.

New plug on order, so all being well will be having a blast around tonight.

Cheers

Mike

[dolly3900]

Resolved.
New plug and fired up first time without a problem.

New problem though
pissing petrol out of the bottom of the carb (overflow pipe)

a few taps with the end of screwdriver on the side of the float chamber and sorted.

Cheers for the advice, much appreciated

Probably be on again sometime when i get confused again.,


Mike