aprilia mx 125 PLZ HELP!

[mx125cc]

I recently bought myself a seized aprilia 125 mx supermoto, and left it with a novice to get fixed, he changed the piston and hommed the barrel, he couldn’t understand why she had locked up, so believing it was the oil pump, he changed it and and set it to run a bit richer. This was due to the fact the bike was fully destricted and had a full sports exhaust.

When I collected the bike and drove it home, it was running fine but wasn’t taking over very well, and usually died out when left to take over. So I decided I would clean the carb out, and adjust the take over myself. When I took the carb apart the bowl was pretty clean and there was nothing blocking the jets, I gave all this a good clean and a blow out. But I all so noticed when I took the air box off, there was no air filter inside. So when I was building the bike together I wrapped abit of girls tights round the hole entering into the air box, so it would stop any dirt or anything getting into the carb.

With the carb and that back on, the bike started first time and took over sweetly. But when I took the bike up the road and went to giver her any throttle she just spluttered really badly and drove like a bag bones. I believed the bike is running to rich or something because it was always very reeky. I have had the plug out of it, and its not that bad, and theres a good spark. So I am now wondering is there anything else that might be wrong, it wouldn’t be anything to do with the ht lead or anything.

I was also wondering how many tanks of petrol would the bike need before its fully run in, I have just been through about 1 tank of petrol, and have been pretty easy to her, but don’t fancy pulling more thought it till the bikes more enjoyable to ride.

Any help would be greatly accepted!

[swainston]

hello,,, hope someone can help,,, i've got exactly the same problem...

stefanallum@yahoo.co.uk

[mx50boy]

sounds like it needs rejetting

oh and btw its tick over not "take over" as you call it

[swainston]

thanks,,, wasn't my bit about tick-over,,, just a guys thread i found that had same prob... haven't got a clue about where to start re jetting though..

[mx50boy]

do a plug chop and see what colour the plug is to start off with

[swainston]

plug chop? as in just change the spark plug you mean? its currently a ngk "r"
BR10EG and the plug is very oily and black..

[NeoGeniX]

Bring it to someone who knows what he's doing...

[swainston]

re plug chop...got it now,,, will try later and see what i find out... thanks

[swainston]

hi chaps,,, well the running rich on oil bit has been sorted,, it was a stuck throttle cable near the oil pump so the marks where not lining up,, but now they are its a lot better and hopefully a few runs will clear it out...

Anyway,,, i checked the CDi unit under seat and its been moded( bit cut in side of unit and the circuit jumper clipped).... so that seems to be done,,

nrg 'r' br10eg spark plug in use,,,,

Power valve/solanoid (or however you spell it!) are or seem to be working too..

So wheres the 33 bhp???? flat out its 60 mph max,, it gets there fairly quick but thats it,,, she's screaming and i'm laying on the tank !
even the local scooter boys can keep with me ! its embarassing(spelt wrong i know!)...

So where have i gone wrong? other than a arrow or similar exhaust is that really all it offers?

thanks for help
swainston..

[mx50boy]

bigger front sprocket

[swainston]

anyone know where i can get a petrol cap for my aprila mx125 the sort with a small breather pipe and valve thingy on it?

any www.?

thanks

[TEZFOSTER]

Hi have same mods as you self mine doing just over 70 mph been told it needs the exhaust chainging to a full power unit or the like of an arrow system and will need the jetting sortin aswell
to many people tell you different ways to to jet it so might be better paying a shop 50 quid or so so u know its running 100 %
if you do find out befor me could you please let me know or when i get spare cash 1st i will let u know
the 11kx mx 125 does have different exhaust to full power unit so basicly the exhaust is strangling your bike

[swainston]

hi tez,

thanks for post,,,, however it must be about 2 or 3 years old now my post above,,, i've moved on from the APRILIA long ago after taking my bike test..
(BY THE WAY>> the aprilia blew up and i sold it for spares...)..

Good luck with yours though,,,, get yaself a 4 stroke when ya can,,2 strokes are fun but dont last long! cheers mate..swainston

[Daniel-S]

Im preety sure that running the bike without an airfilter wont be helping you much!... The air filter doesnt just filter the air going into the engine it restricts te amount off air getting in, so without it you will be running too LEAN and if your getting a rich looking plug its likely to be too much 2 stroke rather than petrol.

i originally planned on getting a geared 50 when i turned 16 but got a Rev and go instead but i spent a good 6 months on the internet for at least an hour trying to get to know the bikes. From what i understand the larger the front sprocket the higher the top speed and the larger the rear sprocket the faster the acceleration so to increase acceleration drop the rear sprocket size down and up the front sprocket. Bikes usually take 100 miles at around 30mph or just keeping the revs low for 100 around 4000-5000 RPM should be good.

And iv just wrote all that out and then realised it was 2008 Fuck My Life! -.-