Help me please, anyone i beg you.How can i get my free revving engine to make as fast as the aprilia rs50 that i am due to race in th nextmonth or so.I want to know how to race prep my bike.It does feel fast at all.After i do a rebuild the power drops off within minutes.Why? Help.Anythink you know about AR50s would help.Oh yeah i need to keep it as a 50cc bike.I already have a micron race can, and am looking for the next modification.
some racing tips:
- Mount a carburettor as large as allowed by the rules of the racing organisation, look for a Keihin, Sheng Wey, Kitaco, Takegawa or Honda carburettor, they're the best. Don't forget to calibrate the carburettor correctly.
- See if you can get thinner cylinderheadgaskets, this will incease the compression ratio and power.
- Enlarge the intake and exhaust portals in the cylinder, or even better, get a 50cc racing kit with a lightweight high pressure piston.
- Get a really good exhaust, don't mess with the exhaust by drilling holes in it and stuff, that'll only ruin it. Gianelly, Polini and Leovinci exhausts are very good.
- remove the speedometer/odometer cable for less motion resistance, if you're racing you don't have time to look at the speed gauge anyway.
- Don't use mineral gearboxoil but use a fully synthetic oil, expulsa 10W40 is very good. It allows smoother shifting, lubricates much better at high revs and is gennerally much better for the engine.
- Use racing oil for the mix, don't use common 2-stroke oil.
- Pump up the tires a little harder for less motion resistance, and use slicks.
- Mount adjustable rear springs on your bike and set them as stiff as they go, this will cost you some driving comfort but will take away a lot of motion resistance.
- The front suspension is oil damped telescopic, right? Fill up the oil in the front forks (use common 10W40) with about 25cc's each. This will make the front suspension harder for better handling and decreased motion resistance.
- Strip everything from the bike that's not really needed, don't drag extra weight around.
- Don't fill up the gastank all the way if you don't need that much feul.
- See if you can get an advancing ignition, this will allow much higher revs and therefor more speed.
- I don't know where the clutch is on an AR50, if it's on the crankshaft then get a different clutch set with the clutch on the primairy gearbox shaft, this will allow much higher revs and the clutch is a lot more reliable. I've seen standard clutches explode (for real), a racing clutch is a must if you're into racing.
- Finally, don't forget to choose the right sprocket ratio.
The one way I have found to make the AR go significantly faster is to find a sprocket off of an AR80 which has 4 less teeth on it than the original 50 sprocket.
Fitting this will reduce accelleration slightly but bring up the top speed to over 55 and this speed is only judging from my standard model so with your racing can you should be able to go even faster and keep up with the RS's
Hope you find this helpful.
Ian
Yo buddy the first thing to do is get rid of that crappy pipe. The micron is very restrictive and if anything will loose power. Why they ever built it i dont know. Exhaust wise u need either a BDK pipe or a Nikon exhaust. I prefer the nikon exhaust for a 50cc even 80cc. Both exhuast are designed for the AR and are pure race use, even though i use mine for the street. Check the back of performance magazine that they sell in the UK. There is no way that an aprilia RS 50 will ever beet the AR. If it does let me know and i have more tips that will work. I know when my AR was a 50cc it was reaching 65mph . I probably could have gotten higher but thats when u get a bigger cc engine. Well good luck and kick that aprilia;s ass.
later
Glenn
Hi Glenn
I've been told that the AR50 is restricted in three places, the carb, the exhaust and the cylinder. Do you know of this? Any tips you can throw me to de-restrict other than changing the exhaust to a Nikon (incidentally, know where I could get one of these from?) would be appreciated.
Cheers
Tim
pete, hi i have a micron race can, 37 sprocket on the back and a 15 sprocket on the front and i also have a honda melody cdi unit which will allow you to rev all the way upto 11000 revs and that does about 55mph, but you could also put a new plug in and fully synthetic oil, which will boost it up a bit. you can also take your air filter off and then it will go faster due to the increase in air sucked in. try and buy a thinner gasket and that will go like shit off a shovel. my ar pisses all over rs50's so this should help, if you want to buy a new ar in about 2 mths e-mail me.
cheers, james from lincoln
i added a pic for moral support.
pete, hi i have a micron race can, 37 sprocket on the back and a 15 sprocket on the front and i also have a honda melody cdi unit which will allow you to rev all the way upto 11000 revs and that does about 55mph, but you could also put a new plug in and fully synthetic oil, which will boost it up a bit. you can also take your air filter off and then it will go faster due to the increase in air sucked in. try and buy a thinner gasket and that will go like shit off a shovel. my ar pisses all over rs50's so this should help, if you want to buy a new ar in about 2 mths e-mail me.
cheers, james from lincoln
i added a pic for moral support.
I've got an ar50 which struggles to break 45 going down hill at a maximum of around 8000 rpm. I'm running with an aftermarket exhaust which was on the bike when i bought it a K&N filter and AE80 Sprockets (the kawasaki field bike from the same parts bin as the AR80). What could I do to free up the revs as 7000-8000rpm is the best i'm getting.
to the guy who got 65 mph out his 50 well done iv got an ar80 witch does 60 at 10,000 , where do you get the nikon can from? cos my staderd one was clogged up with oil so i got some guy to cut it open clean it out and welded it back up, fine untill i got it back, he must have welded some thing up cos nothing was getting through so i put a small hole in the bottom it so it at least worked. that night on the way home it started juddering and chugging and finaly stopped it would not start and its stiff when you kick it over, so it looks live iv over heated it and ceased the engine up, so thats what im doing tommorrow i just hope its not going to be a re-bore, i might be able to get away with some new pisto rings. any surgestions or advice , thanks
i have been given an ar 50 which actually does 72 miles per hour. I really want to get it on the road so i need various parts such as indicaters a battery and a new peice of farring at the front can anyone help???
Wehre are you?
I have the smoke- colored windscreen, and the mounting hardware. I don't have the peice that goes around the headlight.... paint shop mess up.
i live in farnborough
Hi to all you AR owners.
I have just restored my ar50 and it only did 35mph so i did some fiddled around with it and managed to make it 55mph on the flat. i work at an engineering shop so i bored it out to its max got it honed and got a piston for it. then i advanced the timing, found out there was a restricter in the micron exhausts so i took that out, got an ar80 inlet and carb, put the 50 jets in the carb and got the head skimmed at work and fitted an 80 sprocket on the front and this got me 55mph.
i soon got bored of it so took the 80cc engine out of my AE80 rebuild it got it rebored and honed put 50 cases on it and rubbed off the 80 markins, fitted 80 sprockets and it does 77mph. i am so chuffed.
theres a picture of my ar in the attachment.
oh yer please check out my website.
Neat bike- gets me inspired to work on mine again. I just need time, money and parts.
Who is the best source for barts that will ship to the US?
You got any spare body panels that you could sell me?
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