steve austin Posted February 22, 2011 Posted February 22, 2011 Hello all, I know its not a biker forum but I am currently fixing up a 2000 Aprilia RS50 sports moped. Have stripped the carb, cleaned the tank out, put it all back together and got her to start on the choke. Problem is, she will tick over on the choke but if you try to rev her, she dies. Restart on the choke, blip the throttle fully open (to disengage choke) and she revs up but takes ages to rev down and will cut out if not on the throttle holding her above 4k rpm. I suspect carb fault but cant seem to find any mixture adjustment on this weird minarelli carb? Also, hope I am wrong but poss crank seal? HEEEELP!!!!! Have taken on another project when I should be fixing me autoshite up so need to out her asap!!!!!!!!!!
warren t claim Posted February 22, 2011 Posted February 22, 2011 Seriously, Those engines are a bit highly strung. I dread to think what a new carb would cost.
pogweasel Posted February 22, 2011 Posted February 22, 2011 Monkey spunk mopeds are rubbish. Give me a LEOPARDS FANNY BATTER CAR any day.
Cavcraft Posted February 22, 2011 Posted February 22, 2011 Is it an autolobe (as I suspect it will be) and have you put any oil in the petrol tank* at all? I'd also consider looking at the quality of the oil, cheap stuff can make bikes run like crap, even my Vespa doesn't like it. Have you owned it long and if not are you sure you have the correct jets for the carb, especially if there's a spanny or aftermarket air filter fitted? *Despite some bikes being autolube people chuck a bit of 2T in the tank as a precaution and this can lead to poor running problems.
michael1703 Posted February 22, 2011 Posted February 22, 2011 sounds like an air leak, spray wd40 over carb/inlet rubber mating faces and see if wd seals the air leak, maybe adjust the mixture on the needle, does it have an 'E' clip with grooves on the needle, try lifting the needle by trying the 'E' clip on a lower groove
peter9000uk Posted February 22, 2011 Posted February 22, 2011 sounds like an air leak, spray wd40 over carb/inlet rubber mating faces and see if wd seals the air leak, maybe adjust the mixture on the needle, does it have an 'E' clip with grooves on the needle, try lifting the needle by trying the 'E' clip on a lower groove Beat me to it! My money is on an air leak to start of with
scaryoldcortina Posted February 22, 2011 Posted February 22, 2011 Crank seals. On a stroker, the crankcase is full of mixture, and a blown seal lets air in leading to your symptoms. Can be a beggar to change, I'd advise new main bearings at the same time (because usually it's the play in the bearing that buggered up the seal in the first place)
peter9000uk Posted February 22, 2011 Posted February 22, 2011 Crank seals. On a stroker, the crankcase is full of mixture, and a blown seal lets air in leading to your symptoms. Can be a beggar to change, I'd advise new main bearings at the same time (because usually it's the play in the bearing that buggered up the seal in the first place) If the clutch side though that would lead to much smokage
scaryoldcortina Posted February 22, 2011 Posted February 22, 2011 It's pretty much always the genny side that goes. Probably because that side has a 2kg rotating mass on it and the clutch side has a small cog.
wackywacerwill Posted February 23, 2011 Posted February 23, 2011 What he said /\ /\ /\ Whilst your checking for air leaks spray a little squirty behind the flywheel. Give it a wobble up and down too and hope there's no play. From what you say it has all the tell tail signs of a crank seal air leak although it may well be worth re checking the carb to be sure.
steve austin Posted February 23, 2011 Author Posted February 23, 2011 Cheers people, I hope its either the oil in tank or air leak as I dread to think what crank seals are gonna cost labour wise!!! I did put oil in the tank as well as the autolube as when I got the bike, the cable to oil pump had snapped and the previous owner was running premix. Anyhoo, wont be investigating for a few days as back to the coalface but thanks for the info, I knew the Shiters would have the info!!!!!!!!
peter9000uk Posted February 23, 2011 Posted February 23, 2011 Just had a thought, Not sure what engine these use but Aprilia used to use Rotax engines at one time and they were rotary valve crankcase induction
steve austin Posted February 23, 2011 Author Posted February 23, 2011 Just had a thought, Not sure what engine these use but Aprilia used to use Rotax engines at one time and they were rotary valve crankcase inductionI think the 125's do but this is a minarelli engine, also known as the AM6 that goes in most of these little bikes like rieju, derbi etc.
steve austin Posted February 26, 2011 Author Posted February 26, 2011 Ok, an update, flywheel has no play, doesnt appear to be crankseal that side. No excessive smoke although I am running premix AND oil pump as wanted to make sure it was running before putting neat fuel in. Took carb off and sealed reed block (no reeds though??) with gasket sealer, massive improvement as it now ticks over at 1200rpm holding well but still a bit off tune. Cant see any mixture screw on carb, just idle adjustment, worn jet?
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now