fouled spark

[mpourkoulas]

Hello there!
I have a problem with my P200E. the mix in the cylinder is not fully burned so it remains there and the spark becomes oily and black. I tried a smaller main jet (105 insted of 118) with no result. i use lub 2% ratio. except for this my bike runs well. IS THERE ANY CHANCE THAT THE EXHAUST IS DIRTY AND THE MOTOR DOESNT BREATH WELL???PLEASE HELP

[joey]

for a start put the 118 back in, it's not that, a 105 is way too weak and you'll go bang!
It could be an ignition fault or something as simple as a faulty plug, then again it could be a lot of things, but not your jet.
Do you decoke regularly? What timing are you running on? What 2 stroke oil do you use? What plug have you got in?
A lot of questions I know but the more info you can give the better chance someone will be able to help, there's a wealth of experience and know how on this forum so more info please.

[Rudi]

i dont think it has to do with the oil ratio. i run with 4% ,no problem.

could be exhaust is clogged, but that would mean you should feel a sharp decrease in top speed

if not , and the vespa can reach high speeds,( it also means ignition timing is ok), that leaves a too cold spark plug

OR other possibilities that may cause rich mixture: dirty air filter or some kind of partial block in the airway.
choke maybe open a bit
i have a feeling you checked the last two but im mentioning those anyway...

[mpourkoulas]

-spark: NGK B7ES
-oil: Castrol mineral 2T ratio 2%
GUYS, THANKS FOR YOUR INTEREST...
-decoking recently but not the exhaust
-top speed 95-100 km/h

-good acceleration
-good idle
-recently cleaned carburator and air filter

[joey]

You're plug should be hot enough to burn off most residue so stick with that, unless doing long distance in which case put an 8 in, but I'd start using fully synthetic oil as mineral does tend to foul plugs quicker.
If your scoot is standard then 60 to 65 is the top you should be expecting anyway so not too much to worry about.
Is your top speed indicated or checked on GPS?

[Rudi]

b7es should be hot enough...wierd...
i run on b8es (colder than the 7), and its a delight, no carbon at all, and no over heating

i too wouldn't recommend is the castrol mineral... its the lowest grade oil
go for a semi-synthetic ,
maybe that would solve the problem

[Ian]

I've recently had my PX 125 disc kitted with the Malossi 166 and been using the spec spark plug as recommended by Turners B8HS as opposed to the PX 125 B6HS . Only i've gone through 3 plugs in 800 miles though.Any thoughts. The machine is running a little rich and one plug lasted 200 miles and one 35 and the last one 500 ish. Can't figure this out apart from a sh*tty batch maybe

[dto79px]

your p200e should be running on semi sythetic as basic mineral is crude oil and will foul plug and carbon up engine ..

( above ) as with all kitted scoots are you running fully sythetic 2-stroke oil