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chillsrs50
12-08-2013, 09:54 AM
hello all iv just recently got myself a 08 rs50 and unaware of parts for It to improve the performance iv got a few things that I want to do like up jets , pod filters , removing baffles , bigger carb ect as I really don't know anything about them can I have some suggestions on a good setup and also the outcome to the modifications. I want it to look standard but when the time comes have the performance.

thanks

Zav
12-08-2013, 10:10 AM
If you just want pure speed and power use the setup on sig bit in blue

Ust to top out at 75 to 80mph without fairings so with it will be about 80 to 85 mph and went through full tank in 50 miles

And be warned no one on here except me pretty much like pdfilters they all think there rubbish and kil engines but when setup right do a lot of good

chillsrs50
12-08-2013, 11:29 AM
thanks for the response I will look into it , iv heard good things about podfilters just got to get the upjet and the setup correct

Zav
12-08-2013, 12:49 PM
Pod filters are good as long as maintained as in cleaned and reoiled every week

They don't give any power increase on these small bikes nor do they loose power they just make the sound of the engine so much deeper and nicer

But they do take time to tine in but once have there fine

apriliamandan
12-08-2013, 03:20 PM
thanks for the response I will look into it , iv heard good things about podfilters just got to get the upjet and the setup correct

Have you? Maybe you should read a little more then!

Zav
12-08-2013, 03:28 PM
My point proven

I wanna see some one do a test a stock engine with airbox and stock engine with podfilter drive them till the blow up see what lasts longer they will both last about same they'd will both do about same mpg they'd I'll both do same speed they won't make the same noise the airbox is tinny the podfilter is deep and loud

Plus it makes a lot easier to acsses carb and tune the carb

apriliamandan
12-08-2013, 04:34 PM
My point proven

I wanna see some one do a test a stock engine with airbox and stock engine with podfilter drive them till the blow up see what lasts longer they will both last about same they'd will both do about same mpg they'd I'll both do same speed they won't make the same noise the airbox is tinny the podfilter is deep and loud

Plus it makes a lot easier to acsses carb and tune the carb


They require bigger main jet = more fuel useage.
They dont filter out fine particles, like airbox's do, this will reduce the life of the engine.
They're more weather dependant than airbox's, throwin jetting slightly off.
This is why you have had so many engine seizures Zav.

I too love the induction roar from an open airfilter, but a nice noise is the cost of the above. Also, airbox's can be modified (like you have done I think) to sound lovely aswell.

Back to the original question, fit a tuned pipe, like an Arrow or Gianelli. Cast Iron Big bore cylinder (47mm bore = 67cc) and a decent carburettor. You'll need a heavy duty clutch and a range of sprockets to try. This will get you to a real 70 mph and get there reasonably quickly for a moped.

Zav
12-08-2013, 05:47 PM
Yeah I modified my rx one it was crap ran like crap sounded worse so I took the podfilter out of the airbox and put it in front of it behind fairings not had any problems yet

And I haven't siezed on since the change to podfilters my rs blew up once with stock airbox due to warn parts and my rx blew up a piston due to whatever reason

And cast iron 70 kits same power to the stock derbi engines bore due to it being alloy stock trust me I have a few mates I've tuned up and they've all said same about derbi engines alloy all the way

As for clutch the derbi engine doesn't need one with a 70 kit unless it's already warn mate with the red rs is running a airsal m racing 70 kit with stock crank and stock clutch (only done 5000 mile since new) and 21mm and arrow exhaust his never slips at all

As for sprockets a derbi engine can pull 15/53 with arrow pipe and stock carb very slow acceleration but will pull in 6th in tuned right most I've tuned are now running 16/53 with the airsal m racing kits and they top out at 80mph all day long some are using stock 17.5 carbs so are even using 24mm all top out at same speed with that gearing just get there at different rates the best setup of gearing I find with stock engine stock exhaust stock carb is 14/53 tops out at 70 mph ish and for a tuned engine 16/45 takes a while to get there but tops out at 85mph ( we run out of road) that was on a airsal 80 with 19mm carb and arrow exhaust we still had 3k revs to go before we got to end of road


Dan a good way to mod your airbox from my experience is to add a trumpet where the intake is to suck air in then get rid of the foam sheet and use a TNT small one filter attached to the carb sides tube inside the airbox runs like normal needs 1 maybe 2 sizes upjet but it makes a deeper tone

As for new shape rs and derbi airboxs best way I've found to mot them is get rid the restrict the air in due to the inlet touching the frame and only having half the inlet able to suck air in what we found is good to go is use a silicone tube same diameter of the carbs inlet and move the tube up to where the old airbox was so its out way of weather and use a double layer podfilter of make a box with a inlet that sucks air from under the frame (both of theses also need a 2 or 3 size upjet

Reason I know this is I've tried on mates rs and debris and my own they work give a nice sound and still keep reliabity if done right

apriliamandan
12-09-2013, 02:21 PM
Yeah I modified my rx one it was crap ran like crap sounded worse so I took the podfilter out of the airbox and put it in front of it behind fairings not had any problems yet

And I haven't siezed on since the change to podfilters my rs blew up once with stock airbox due to warn parts and my rx blew up a piston due to whatever reason

And cast iron 70 kits same power to the stock derbi engines bore due to it being alloy stock trust me I have a few mates I've tuned up and they've all said same about derbi engines alloy all the way


Well thats rubbish, It depends on the port timing of the cast iron 70 kit.

I also remember your Airsal 70 kit seized after a few hundred miles.

Zav
12-09-2013, 02:28 PM
Yeah used stock airbox what I found out to have a air leak was a very light seize tho still running nw done close to 5000 miles on that puppy still has 101psi

And dan alloy makes up to 1.7 times more power than alloy rember I have used stickyparts 120 kits I have mates bikes that I have set up with 90cc kits and they still gave about same power at top end they do have a little more ow end and that's about it

apriliamandan
12-09-2013, 02:35 PM
Yeah used stock airbox what I found out to have a air leak was a very light seize tho still running nw done close to 5000 miles on that puppy still has 101psi

And dan alloy makes up to 1.7 times more power than alloy rember I have used stickyparts 120 kits I have mates bikes that I have set up with 90cc kits and they still gave about same power at top end they do have a little more ow end and that's about it


101psi is low mate.

That last paragraph made no sense, but any performance difference will be down to port timing, pipes and carb set up. Yes the Derbi alloy cylinder might make more power than a cheap crap big bore kit, but that will be down to port timing, not whether it is Alloy or Iron.

Zav
12-09-2013, 02:48 PM
Still starts within quarter a wheel turn when bump starting and still revs of the clocks with no problem

And it does make sense I've said it many times before alloy kits are more powerful full stop and derbi ports are a very good standard raise the exhaust a bit and raise the boost and transfers and clean all the ports up and it flys but it will eat piston rings

Cast revs less and is now getting even more out dated I admits some cats kits are good but most are crap as Patrick always says about stock am6 engines get rid of the cast get the alloy it's a better kit more powerful

apriliamandan
12-09-2013, 03:55 PM
Still starts within quarter a wheel turn when bump starting and still revs of the clocks with no problem

And it does make sense I've said it many times before alloy kits are more powerful full stop and derbi ports are a very good standard raise the exhaust a bit and raise the boost and transfers and clean all the ports up and it flys but it will eat piston rings

Cast revs less and is now getting even more out dated I admits some cats kits are good but most are crap as Patrick always says about stock am6 engines get rid of the cast get the alloy it's a better kit more powerful

Im not going to argue with you Zav, you simple do not understand what you are typing. You need to be careful you don't give wrong information out there.

There simply isnt anything in performance whether its cast iron or alloy. Yes, alloy cylinders displace heat better than Iron, the plating is hard wearing so providing the bike doesnt seize it could last longer. However cast iron can be honed after a slight seizure and re-bored.

The performance differences you have found between certain barrels are port timing, not the material. The Am6 alloy barrels had a larger exhaust port, which is why people choose those, over the later cast iron cylinders.

Atleast think before you type Zav.

Btw, 110 PSI is low, there no doubt about it. An engine with slight low compression can still rev out, but will lack low down power. You probably wouldn't notice unless you had the same set-up with the correct compression. Stock Am6 engines are about 120PSI.

Zav
12-09-2013, 06:43 PM
Easiest way to explain this to you is get a airsal m racing 70 kit and compare it to the stickyparts 120 kit the ports are similar and both twin ringed that will prove my point that alloy is better

I ust to think like you till I fitted a cast on a 19mm arrow exhaust setup then did a alloy with 19mm and arrow exhaust the cast goes nicely pulls well but you ride a alloy and it's a totally different bike as you have no low end very minimal mid range and a lot high range

So until you try a alloy kit with similar ports to a cast please shhh

apriliamandan
12-10-2013, 06:18 AM
Airsal and cheap crap stickyparts kit porting is totally different Zav, the quality of the ports, the layout of the ports and the finish of the ports. Also the Airsal has a different compression ratio.
It is fact that whether its cast iron or alloy theres no real difference is performance. Theres no point trying to convince me, because it simply is not the case. My father has been building 2 strokes for many years, he has just confirmed with me that you're wrong.


Yes, alloy kits transfer heat quicker than Cast iron cylinders, however this is not noticeable on the road. Alloy kits are generally harder wearing because they are plated. The benifits of Cast Iron is that they are much more stable than alloy kits (less expansion with heat) and you can re-hone them after a slight seizure, whereas plated kits your stuffed.