Hello! I have some pretty basic questions, so I think this is the place to put them? Any way, im not a total noob, I've raced 2 stroke kart's in the British championship for 9 years since I was 10, and I've owned an NRG Power DD and an RS125 which was pretty 'tuned' with bolt on stuff mostly Now though, I have an Aprilia SR50, and I have been slowly buying all the bits I want for it and im nearly at the point of putting it all together, the spec is - S6 racing 70 kit, yasuni c16, MHR 21mm dellorto (on premix), short intake manifold and pod filter instead of an airbox. The gearbox will be pretty standard for now, just stronger clutch springs, lighter rollers and a stronger contra spring 1. I have no idea where to start on Jetting, what would you recommend please? 2. What spark plug? i dont want to be melting the piston 3. What oil ratio? i was thinking 4%? 4. What roller weight would you reccomend? i was thinking 4g? Any help is appreciated, thanks :good:
Been sent a fooking 19mm MHR carb instead of a 21mm! cba messing about with a company all the way over in Germany, so this will do for now, i would like to know a starting point jet on this carb instead now please
yeah lol, oh well. aye i see sm is banned also now haha, i still do a bit of snooping lol racings over for this year but am stickin to the rs for another year thanks am on this cause i got a jetforce in bits and when it comes to rebuilidin it ill need a LOT of help lol
lol now all we need is me back, which is never going to happen, he got countless chances i got one lol. awh well. yeah am 16 in feb so hopefully have her going by then, neeed a barrel and a exhaust for it,
yeah but i got the whole lot for free so i want to spend as little money as possible on it to see if i can get it going first before i spend any money on it tuning it. its a fuel injected model too which people say give bother
sell the rs... you pay for them every three years "as in you spend on them what there worth over and over again using them on the road) as for roller and jetting questions, if youve raced karts for years who has set them up? surely starting the bike would give you an indication of whats right and what isnt. as per the million odd posts ive replied to with this exactt reply, i shall reiterate bash in some mid weight rollers (around the 5g mark) put some mid weight springs in, throw a big ish jet in (around the 90 mark) and start with the needle in the middle. then start the bike and have a read of the really clear and concise roller and carb guides in the relevent section. use the stock plug and ajust accordingly. i usually run a slightly colder plug (so a br9es rather than the stock br8es as i like em a little rich on idle and this kills the 8's..... oil i run 2% happily
Thanks for that! As for the RS i sold it just over a year ago. I have always set my karts up, but they use diaphragm carbs with needle jets, still, its always handy to have a basic starting point I will put a 90 in, I know how to set the jetting from there lol just thought it would make my life a bit easier to have a starting point cheers for the info on the plug and oil ratio, these thing vary massively in karting, 2% in the class i race in would seize it, and an 8 plug would melt the piston I'll get pics up of the SR when it is completed, hopefully around new year
HEEELP im properly confused now, fitted all the parts, fuel mixed at a very safe 4%, 98 main jet, and it fired straight away.. then i let it warm up and cool down a few times just blipping the throttle and it seemed spot on, temp wasnt too high or anything... an hour later i took it up our lane and it was a bit fluffy at the bottom, which i expected it to be a bit rich but it was fine in the higher revs, so i turned it offf after 3 or 4 mins gentle riding and the cylinder was soo hot! but them temp gauge said it was fine .. basically now it wont start, and it only has 90 psi compression, so im thinking its lightly heat seized? the plug was white, but ive literally done less than a mile so i dont think i can really go by that any ideas lads?
Been there, done that :banghead: Pump belt had come loose and I didn't notice, went for a quick test spin with my new barrel and pulled up 200yds later with steam shooting out of the rad.
