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View Full Version : The Fastest RS50 "If Money Was No Object" What would you do



wizwiz
09-30-2013, 05:13 PM
Hi All, We have just brought a 2006 with an AM6 engine RS50 with some accident damage Cat C that we want to tune to the Max and Customise the overall appearance. My question is if YOU could buy any parts for your RS50 without concern for money what would you do. Big Bore kits, Pipes, Reeds, Carbs Bodywork, gearing, etc etc. I would appreciate as many tips as poss. There seems to be so many suppliers of parts and its left me scratching my head. I await in anticipation..... PS has anyone tried the Athena 80cc Big Bore Power valve kit?

mattology
09-30-2013, 06:35 PM
CR125 swap ;)

Zav
10-01-2013, 01:26 AM
If I had the money I would wanna do a mxs build

It involves this kit http://www.maxiscoot.com/pack-cylindre-vilebrequin-pot-mxs-gp90-course-46mm-am6.html/?campaign=magazine/gp90

Needs a 38mm carb or bigger
With upgraded clutch
15/40 gearing would have to be custom
with tp 6th gear
doopler inner rota
and for just a bit more fun ad some nitro meth to the mix and run it full nitro meth

Should make around 35 to 39 hp when setup right without the nitro meth and top out round 105mph maybe more

Who knows with nitromethane involved

apriliamandan
10-01-2013, 11:22 AM
Put a 125ccc motorcross 2 stroke engine in and keep the fairings off to show off that mental engine swap! Basically what Matt has! Think he's pushing out around 40hp! (imagine that on L plates...)

wizwiz
10-01-2013, 04:10 PM
If I had the money I would wanna do a mxs build

It involves this kit http://www.maxiscoot.com/pack-cylindre-vilebrequin-pot-mxs-gp90-course-46mm-am6.html/?campaign=magazine/gp90

Needs a 38mm carb or bigger
With upgraded clutch
15/40 gearing would have to be custom
with tp 6th gear
doopler inner rota
and for just a bit more fun ad some nitro meth to the mix and run it full nitro meth

Should make around 35 to 39 hp when setup right without the nitro meth and top out round 105mph maybe more

Who knows with nitromethane involved
Thanks for this link and tips. This is the sort of thing I was hoping for. What a gr8 piece of kit. Do you know anyone who has fitted it?

Zav
10-01-2013, 04:14 PM
No mate but I've seen vids on YouTube and they rock

But there a full race setup so can only prob 3 k miles before needing new top end and that's if your nice to it when there set up for road use what's about 30hp they apparently last around 5k to 7k miles mattering how nice you are to it

apriliamandan
10-02-2013, 01:03 PM
If you want to keep with the Am6 engine, then I'd suggest keeping it a mild set up otherwise you'll have endless issues with gearbox, clutch and going through pistons.

Remember these 'race set-ups' have HUGE ports (more holes than bore), which puts huge stress on the piston rings. Unfortunately, most high spec top ends are single ringers, so you'll be knackering up pistons very quickly. This is why I suggest you go for a dual ring piston kit that uses a cast iron barrel (cast iron can be rebored and honed). The more mild ported kits are much more ridable and still can produce decent power and have a much nicer power delivery! I suggest a Malossi 80cc, TP75cc or a Polini 80cc cast iron kit. I would stay away from the long stroke kits unless you have another bike....

Regarding carbs, 21mm - 24mm are generally best for mild 70/80cc set-ups. Too bigger carb and you'll end up loosing power and reducing torque. Get yourself a nice dellorto 21mm or a Mikuni 24mm carb coupled with a quality airfilter.

Crankshaft will have to be uprated, preferably with over sized crank shoulders. Common failure if the crank shoulder to shear off on the fly wheel side when running a tuned top end kit. I recommend a Doppler endurance crank with over sized bearings to go with it. Top performance do cranks aswell....

Even with a very mild set up you'll get a lot of clutch slipping when launching off, so you'll need stiffer clutch springs and heavy duty clutch plates. Barnet clutch kits are the best from what I have heard although Polini and Conti do some very good clutch kits for a good price.

Key to performance with a 2 stroker is the expansionchamber. You'll need to find a exhaust that matches you set up just right.

You'll need to adjust the ignition timing and fit a 'race' CDI unit for a better and more suitable timing curve.

Oh and a HUGE set of main jets aswell as throttle slide needles and pilot jets to get her running spot on!

Keeping the standard 39mm stroke, you'll struggle to get over 18-20hp. With a highly ported long stroke kit, you might see 25hp very briefly...

Stay away from meth unless you want holed pistons....

Zav
10-02-2013, 01:48 PM
If money isn't a object tho why would that bother him if he's got the money he can put up with the best couch best gearbox best whatever Anna's many pistons and barrels as he wants

There is also a new airsal 88cc kit what has twin rings but now sure when it's coming out

apriliamandan
10-02-2013, 02:49 PM
If money isn't a object tho why would that bother him if he's got the money he can put up with the best couch best gearbox best whatever Anna's many pistons and barrels as he wants

There is also a new airsal 88cc kit what has twin rings but now sure when it's coming out


Why would it bother him? I explained the issues with heavily ported & tuned set ups Zav....

1) Wont be able to ride any distance
2) Never garentee he'll be able to complete the ride
3) Always replacing pistons (pistons don't let go when he's on the drive way, it will let go 100 miles away...)
4) Forever replacing bearings and gearbox's
5) Has he got the skill to modify the crank cases???

Read my previous post!

Obviously money is limited, why would any one spend 3 million on a Am6 engine.....

Zav
10-02-2013, 03:11 PM
I just gave him what he's asked for

im not the type to put people down like others all he wanted to know is what he can do with no limit to money so I told him he didn't ask for all the negatives and what he should do

wizwiz
10-02-2013, 03:30 PM
Hi Guys thanks for the tips. Longevity is important. I don't want to break it down every few Hundred miles. But 20 Plus HP was also my target. Where would I get a long stroke crank and cylinder kit. D they make them is cast? with a twin ring.

Zav
10-02-2013, 03:35 PM
There is a cast twin ring tp 86cc kit but it will only have about 18hp tops at rear wheel as Torah is struggling to get more than 19at rear wheel with single ring and ally kit what have a lot more oh then cast twin ring

and it's here http://www.vsmotoparts.com/brands/yamaha/tzr-50/top-performance-maxi-kit-86cc-minarelli-am6

will Need somet like a jollymoto 80cc and a 32mm carb or bigger for pure high end power

apriliamandan
10-03-2013, 09:36 AM
You will not be able to get 20hp++ for an AM6 engine, while keeping it relatively reliable. You will find the bike very lively with a true 15-18hp motor as these bikes are so light!
Zav, I am not putting anyone down...I am being realistic here.
As I have mentioned before, Stroker kits require crank cases being opened out....do you have the know how to do this?

Read the theads about Tora's Derbi, he has a Airsal 88cc stroker kit (with port mods) and he is getting 18hp at the rear wheel. This is a crazy amount of power from such a small capacity engine....think about the RD125's, doubt they're getting any more than that!!!

The best set up for longevity and performance would be ; TP75 Pink cylinder kit, or Airsal 80cc cylinder kit (actually its a true 76cc kit), Doppler crankshaft or equivalent and a 21mm dellorto carb. Jetted right, with plenty of oil going through it, it should last a good 5,000 miles without any issues. This should put out with all the other mods around 14-16hp at the rear wheel maybe? (would need to be confirmed but around that) and will leave any 125 4 stroke sports bikes like the Sach XTC, YZF R125 and Rieju RS3 125's standing and be far more fun as its half the weight! :)

Zav
10-03-2013, 09:50 AM
It's a skill that can be learned or paid to do and I agree 100% with the airsal 80 setup dan just posted except the 21mm I would go for 28 or 30 as I'm using a 24 mm with my airsal 70 and I still think I can go bigger with it

apriliamandan
10-03-2013, 01:14 PM
I wouldn't go any larger than 24mm on a road set up, but by all means play around with different carburettor sizes.

Zav
10-03-2013, 02:45 PM
Why would you not go bigger than 24mm if a 70 cc kit can take a 24mm and run great then it would just be holding back the topend on the 77cc kit as that's what the airsal kit is

Nuttynat416
10-03-2013, 03:07 PM
shove a 2t kx 250 engine in there and try not to kill yourself !!

If you were nuts aha !!

apriliamandan
10-03-2013, 03:13 PM
Why would you not go bigger than 24mm if a 70 cc kit can take a 24mm and run great then it would just be holding back the topend on the 77cc kit as that's what the airsal kit is

You seem to think bigger the carb, the more power you get Zav.... 21mm-24mm is large enough for all stock stroke engines. I think you need to do a little research of the basics Zav....

Nuttynat's right, go crazy and shove in a KX250 lol

Zav
10-03-2013, 03:19 PM
well if machan however spell his name can run a 28mm and say its better than any other size carb on a stcok 50cc engine then why would a 24mm be to big or a 28mm be to big for a 77cc heavly ported topend

Nuttynat416
10-03-2013, 03:27 PM
Those kx250s scare the hell out of me, rode my uncles road legal one and as hard as I tried couldn't stop the front wheel thinking it was some sort of aircraft aha !

apriliamandan
10-03-2013, 03:57 PM
well if machan however spell his name can run a 28mm and say its better than any other size carb on a stcok 50cc engine then why would a 24mm be to big or a 28mm be to big for a 77cc heavly ported topend


Oh dear Zav....you've got a lot to learn! He was managed to get more peak hp on a dyno with a 28mm carburettor - yes, and what? His bike was not being used on the road. The powerband would be crazily narrow, no bottom end power, it would be dreadful on the road!!! Why do you think everyone runs 21mm carbs? Let me tell you, its about compromise between low down power, ridability and top end power.

Remember, where you gain, you loose somewhere else!

Would love a go on a KX500 Nat!

Zav
10-03-2013, 04:34 PM
See that's where the problem is I only drive in the powerband I don't use anything else and use the gearbox to keep it there

RS_Patrick
10-03-2013, 05:50 PM
Zav's got a close ratio gearbox installed ;)

mattology
10-03-2013, 08:09 PM
125 !!!

scottydog
10-04-2013, 10:32 AM
250 !! :banana:

RS_Patrick
10-04-2013, 01:00 PM
AM6 !!!!!

with Pink Top Performances kit, Doppler ER1 Crank, TP Race Clutch with extra stiff springs, TP Yellow CDI, 24mm mikuni TM24 with custom made adaptor for stock airbox, custom made throttle cable part from splitter to carb, 24mm carb manifold with oil injection nippel, 0.40mm Carbon/Kevlar reeds, B11EGV sparkplug, Modified airbox, Giannelli Race pipe, 15/47 gearing and some slight modifications to various parts.
That was my old setup wich was good for ~90mph, but got even more out of it with a smaller rear sprocket :p:

Probably will install something similar again with a true 70cc+ pipe and a topperformances 6th gear.

Nuttynat416
10-04-2013, 01:22 PM
love that setup Patrick, If only money was no object :P

RS_Patrick
10-04-2013, 05:56 PM
Yeah, was really reliable also, never gave me problems exept with the cops... :(

wiseman
10-06-2013, 05:42 AM
If money is no object, why waste it on an RS50? just go and buy an RS 250, or RG 500 V4 two stroke. But im guessing your young and not fully licensed yet.
But seriously, i would just swap out the engine for a 125, rather than stressing out the 50 with a big bore kit.

RS_Patrick
10-06-2013, 08:24 AM
More fun getting as much out of that little engine as you can, much more satisfaction also if people ask you how you got it to go so fast.
Engine lasted me 10k km with out problems.

apriliamandan
10-06-2013, 02:01 PM
If money is no object, why waste it on an RS50? just go and buy an RS 250, or RG 500 V4 two stroke. But im guessing your young and not fully licensed yet.
But seriously, i would just swap out the engine for a 125, rather than stressing out the 50 with a big bore kit.


Wiseman, you're being too wise! No seriously, you're missing the point of small capacity tuning! Its far more satisfying getting a 'slow' bike go fast!
Plenty of full motorcycle licence holders tune small CC bikes...

The Am6 engine can be tuned to stay with 125 2 strokes from the 80's so can be a right laugh! Oh and for us nippers, insurance is still as cheap as a 'ped!

wizwiz
10-07-2013, 04:17 PM
Hi Guys, Actually I am 47 and my eldest son is 17. I have another 12 and 6. My days on 50's was the FS1-E. I had so much fun as a teenager. clip on bars. YB100 Carb. Rotary Valve cut and cover had a new tube for the YB100 carb. Loadsa fun. One of my friend's was UK 50cc Sprint Bike champion so his father helped tune my Fizzy's. We want to have some fun with this RS50. Not for me to ride ( I will though ;-) but overweight now) but more for my eldest son. He has had scooters 50cc and 125cc but this is a Laugh. Some fun with my kids, and perhaps a trip back in time for me. A challenge perhaps. Anyway I really do appreciate all your tips. I have noted the Athena 80cc with a power valve. A few quid but looks like a very useable setup with low down torque. Has anyone tried it??? The Bike is on an 06 plate but has the AM6 engine. I paid 200 quid for it. Cat C Write off. Its had a front end and side accident. I am goner try to wrap the fairing. Perhaps stealth Black or carbon fibre mix. Anyway we will take pics and post them on here as we progress. Thanks Wes

RS_Patrick
10-07-2013, 09:38 PM
Problem with the Athena 80cc (actualy 76cc) Powervalve is you would need a specail pipe for it also to get the full benefit of it, didnt try it and never seen one in person.

apriliamandan
10-08-2013, 02:23 PM
Hi there wizwiz. I would suggest you get an Airsal 80cc kit (true 76cc actually ;) ) coupled with a 21mm Dellorto carb, set of 0.35 carbon reed petals, performance exhaust (makes the biggest difference, like night and day), like a Gianelli, LeoVince or Arrow and a heavy duty clutch. Oh and very importantly, a uprated crankshaft, unless you want it to throw a rod or snap an arm when you're tucked in! You'll need a pack of jets and a few sprockets to play around with. Biggest sprocket you can fit is 15 tooth I think. Stock is 12:47.

The Airsal 80 (76cc) is an aluminium plated kit with a bridged exhaust port (better for the rings) so should last a fair while. They are very well priced as well.

These bikes can be mental with the right set up and leave 125 4 strokes for dust!

RS_Patrick
10-10-2013, 11:03 AM
Giannelli and Arrow pipes are no good for 60cc+ kits, the old ones where, but the new ones are really a bit restricted for anything over 60cc.


If you want a good big bore pipe get a Yasuni R3, or for a long stroke kit a R4

durkn
12-17-2013, 02:23 AM
Has anyone stuffed a CR500 engine in one of these?
Will the frame hold up?

Ive got a street legal CR500AF dirtbike & an RS-250, but id like to have another CR500 powered street bike.
Im thinking an FZR400 roller might be a better option than the RS-50...

Zav
12-17-2013, 04:49 AM
Has anyone stuffed a CR500 engine in one of these?
Will the frame hold up?

Ive got a street legal CR500AF dirtbike & an RS-250, but id like to have another CR500 powered street bike.
Im thinking an FZR400 roller might be a better option than the RS-50...
some one has put a cr500 in a 50cc frame it was a derbi Senda and he died in a crash riding it
and quiet a few have put them in tzr125s and rg125s and there frames are weaker (I know this from personal experience)
But the rs50 frame should hold up but it will need a lot of reinforcement and then you will have to find a custom pipe for it and so on

Your prob better off with the fzr400 or a little 250 frame

apriliamandan
12-17-2013, 01:10 PM
I reckon a 99-05 frame would cope the the power of a CR500 engine.

Spike died on a Derbi Senda with CR 500 engine (apparently), hardly a surprise though, would be a manic machine!

Zav
12-17-2013, 01:13 PM
I reckon a 99-05 frame would cope the the power of a CR500 engine.

Spike died on a Derbi Senda with CR 500 engine (apparently), hardly a surprise though, would be a manic machine!

The 99 to 2005 is quiet a strong frame but the swinger will need eather reinforcing or replacing with a different one

mattology
12-17-2013, 08:06 PM
Has anyone stuffed a CR500 engine in one of these?
Will the frame hold up?

Ive got a street legal CR500AF dirtbike & an RS-250, but id like to have another CR500 powered street bike.
Im thinking an FZR400 roller might be a better option than the RS-50...

I would say that I may or may not be working on a KX500 swapped "SuperSingle" road racer this spring.. The vibrations are going to be the toughest thing to deal with. Even with my little CR125 powered bike, and its twin that will be done very soon, the vibrations are tough at certain RPM's.

The motor would fit relatively easily. There is a lot of room between the spars of the RS50 frame, and the frame itself is pretty heavy.

freedomgli
12-18-2013, 02:50 PM
I've thought a lot about what road bike to transplant a 500cc 2-stroke but I don't have any answers yet. I'm still brainstorming. As much as I want a hopped up RS50 I don't think the RS50 is the best choice for a swap of this magnitude. I'd rather use a better chassis even if it ends up being heavier. By better I mean like Honda NSR250R (MC28) or Honda RS250 or Yamaha TZ250 (3YL). The trick is keeping the weight down so you get the wicked performance without the bike falling apart or getting torn apart. Seems everyone complains about the vibrations. Why is it that all the swaps I've seen use solid mounts? Why don't people use vibracoustic engine mounts?

I've even considered a RSV Mille chassis as you can find them so cheap, but I worry about weight. I'd love to build a few Bimota-/NCR-esque bikes or a Moto2 or Moto3 replica.

Zav
12-18-2013, 03:00 PM
I've thought a lot about what road bike to transplant a 500cc 2-stroke but I don't have any answers yet. I'm still brainstorming. As much as I want a hopped up RS50 I don't think the RS50 is the best choice for a swap of this magnitude. I'd rather use a better chassis even if it ends up being heavier. By better I mean like Honda NSR250R (MC28) or Honda RS250 or Yamaha TZ250 (3YL). The trick is keeping the weight down so you get the wicked performance without the bike falling apart or getting torn apart. Seems everyone complains about the vibrations. Why is it that all the swaps I've seen use solid mounts? Why don't people use vibracoustic engine mounts?

I've even considered a RSV Mille chassis as you can find them so cheap, but I worry about weight. I'd love to build a few Bimota-/NCR-esque bikes or a Moto2 or Moto3 replica.

The rev miles chassis is lighter than a rs250 chassis and the rs50 99 modal chassis is heavier than a 250 chassis according to the 250 forum

Micah / AF1 Racing
12-25-2013, 11:06 AM
If I were doing another RS50 I would be installing the AM6 into a late model Honda RS125 chassis, I would be using my micro roots blower with 28mm carb on intake side, probably a stroker, pv equipped motor, fueled by alcohol and out to tear down some small bore two stroke records! I would have to mod my carb for on-the-fly mixture adjustment. Even a blown/boosted 50cc full race kit would be fun in a 160lbs package!

mattology
12-25-2013, 05:24 PM
40lbs is significant. My 125 powered RS50 is 204lbs with a close to dry tank

Micah / AF1 Racing
12-25-2013, 05:31 PM
A 96-98' Honda RS125 chassis WITH the magnesium wheels, and a few other parts and an AM6 can weigh under 150 lbs WITH fuel...awesome chassis!