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**aalop143** · 02-14-2009, 01:10 PM

nice info dude but we want more about to increase the top speed

**psycho 98** · 02-14-2009, 01:26 PM

Originally posted by c_sbk View Post

Pics plz if possible

.

Here you go check this ad Yamaha RX/RD spares - xBhp Classifieds : Buy & Sell

**torqu3e** · 02-15-2009, 11:54 AM

Originally posted by aalop143 View Post

nice info dude but we want more about to increase the top speed

If you read the last part of the post,

You will see, I tell you to get the RDD CDI, which will increase your performance by a lot, get a UNI filter, fiber reeds, high compression head. All these things are mods which are external, that you dont have to port the engine or use a chamber and do extensive jetting.

Ron supplies a jet with the UNI, so you just put that in once, and that is it you are done.

This will give you a nice boost in power all around the rev range.

For info on any of these, PM/mail me.

**bhpistorqintorpm** · 02-17-2009, 07:47 PM

RX 5 speed conversion

at first 'm thankful to both Sandeep and Torqu3e

Originally posted by torqu3e View Post

Let me demistify a lot of your doubts and misconceptions, I have been into RXs for the last 7 years now, own 2 of em, details for both on the page before this, have done enough research on em to know what all is possible on them and what aint.

Lotta you people may not know me and might think i have only 4 posts so am a newbie, you can search for the same nick on RDDreams:Indias First and best Automotive Forum and you will come to know.

4 speed can be converted to 5 speed no problem there, parts needed are...

5 Speed block piston kit - Rs. 4800 (this is the new price) but difficult to get nowadays.
5 speed gearbox - Rs. 3400(old price), not sure of new price
5 speed head - Price unknown, impossible to get new, used is next to impossible
5 speed carb - rs. 2500 brand new, almost impossible to get
sprocketing should be changed to 16/37, but aint necessary
With all these mods I recommend changing the crank too, new price is rs. 2800 again not available.
New bearings advised which cost 800 rs.
new oil seals cost about 150 odd rs
new gasket set cost about 170 rs
labor is free for me cuz i do all this myself, else anywhere from 800 to 1800 is normal

Now that you cant get the 5 speed head, and if you use a 4 speed head your compression goes really low, what do you do, as sandeep said shave and mod the head, find me one guy who can give you the right kinda job a on a head, calculated squish width, angle, MSV figures, centering of squish, combustion bowl volume, squish clearance.

The only person who can do that right is Ron Chinoy.

Secondly very difficult to find a 5 speed carb, my advise use the 4 speed carb, it is way better for a 5 speed than the 5 speed carb.

I know this because I have run 8 different carb setups on my RXs, not counting another one which I have for which an interface plate is being machined....

now I have 2 problems:

first is availability of spares
2nd financing

cost of available spares excluding all the optional changes and labour

piston kit- 4800
Gear Box- 3400
Bearings- 800
OIl Seals- 150
Gasket- 170

total Rs.9320

can I go for changing the spares in stages. say piston kit change first and later the gearbox and other things. (that is around 5k expenditure at first stage)

important factor would be finding the mechanic who can 'do' the 4speed head.
@Sandeep can you please help me in this regard

'm planning for these changes in a couple of months. but till then i wanted to know if my engine is all right or does it needs a immediate rebore or bore change?
at idle speed the engine emits that gzzz.. sound though light but it is present. but when you rev it hard it sounds solid and pick up is great. it touches 80kmph easily. i have not crossed 85 till now(haven't had much time with the bike)
please friends help me with this.

PS: whatever it is - riding this pocket rocket is one helluva experience. i do not regret paying little high for this. just love to rev it to the limit

**Sandeep_K_Ram** · 02-17-2009, 08:18 PM

Umm I don't know if its a good idea to do it in stages.

I used the 5speed bore piston kit with the 4speed gbox and the 4speed head. I was running 4speed sprocketing for a while. It sucked.

Even if you dont get the head worked...you need to get the gearbox and sprocketing changed along with the bore piston kit.

**bhpistorqintorpm** · 02-17-2009, 08:34 PM

Originally posted by Sandeep_K_Ram View Post

Umm I don't know if its a good idea to do it in stages.

I used the 5speed bore piston kit with the 4speed gbox and the 4speed head. I was running 4speed sprocketing for a while. It sucked.

Even if you dont get the head worked...you need to get the gearbox and sprocketing changed along with the bore piston kit.

looks like the waiting period is only gonna increase
thanks for the quick reply Sandeep. that brings to the next question : can i still use the present bore set up, can we decide based on the engine sound and the performance.

**torqu3e** · 02-17-2009, 08:55 PM

My advice would be. Do the bottom end first, that is the gearbox, bearings and oil seals and if you can the crank too or atleast refurbish that, and then the top end.

No mech you can find will give you the correct head mod for the 5 speed barrel, there are TONS of parameters that one needs to know to mod the squish on heads and noone I know except Ron Chinoy in India knows that right.

**Sandeep_K_Ram** · 02-17-2009, 09:45 PM

Originally posted by bhpistorqintorpm View Post

looks like the waiting period is only gonna increase
thanks for the quick reply Sandeep. that brings to the next question : can i still use the present bore set up, can we decide based on the engine sound and the performance.

Whats wrong with the current setup ?

Basically, it boils down to this -

For a proper 5 speed mod you are looking at least 10K.

If you want to retain your 4speed as it is ...just get a rebore done or a new bore piston kit. Then you can go for porting/filter-upjetting/etc etc etc you can use the money you save on the 5speed conversion for all this work.

**bhpistorqintorpm** · 02-18-2009, 02:26 PM

Originally posted by Sandeep_K_Ram View Post

Whats wrong with the current setup ?

Basically, it boils down to this -

For a proper 5 speed mod you are looking at least 10K.

If you want to retain your 4speed as it is ...just get a rebore done or a new bore piston kit. Then you can go for porting/filter-upjetting/etc etc etc you can use the money you save on the 5speed conversion for all this work.

nothing wrong with the current setup. it is running fine for me. but one of the mechanics at yamaha service center said the engine needs a new bore kit. so i was thinking instead of replacing the 4speed bore kit- i would go for complete 5 speed make over(greedy..!?

). but because of some financial commitments at present thought of making it in stages.

@torqu3e
thanks for the advice

the more obstacles 'm facing the urge to to change over for 5 speed is increasing

.

**psycho 98** · 02-18-2009, 04:35 PM

@csbk this is how the filter looks.

**torqu3e** · 02-18-2009, 06:42 PM

psycho 98

remove the 2 bell mouths, use a single slimmer pvc pipe from the carb rubber boot to the filter, performance will improve.

**Joel** · 02-18-2009, 08:04 PM

That belly like shape will end up acting as a intake resonater and building mid-range, however at the cost of top-end revs. Remember the legth of the intake tract, before and after the carb will make a lot of difference. Most people get this wrong and then blame the engine. Intake tuned length is really critical.

**Sandeep_K_Ram** · 02-18-2009, 09:01 PM

His bike revs out to 8.3K easily in 3rd gear. Top end - for a 4speed - is good. There is no excessive slackening in 4th. I felt his bike was in near perfect tune when I rode it. I would say he better leave it at it ...

**torqu3e** · 02-18-2009, 09:59 PM

Joel it will not work like a resonator, the positive pressure pulse from end of filter will mess with the negative from the carb in the intake cycle and there would be a pressure front formed there.

A typical fluid dynamics problem.

Sandeep, the bike will work better with a shorter intake tract.

**psycho 98** · 02-19-2009, 12:43 PM

Originally posted by Joel View Post

That belly like shape will end up acting as a intake resonater and building mid-range, however at the cost of top-end revs. Remember the legth of the intake tract, before and after the carb will make a lot of difference. Most people get this wrong and then blame the engine. Intake tuned length is really critical.

Originally posted by torqu3e View Post

Joel it will not work like a resonator, the positive pressure pulse from end of filter will mess with the negative from the carb in the intake cycle and there would be a pressure front formed there.

A typical fluid dynamics problem.

Sandeep, the bike will work better with a shorter intake tract.

Originally posted by Sandeep_K_Ram View Post

His bike revs out to 8.3K easily in 3rd gear. Top end - for a 4speed - is good. There is no excessive slackening in 4th. I felt his bike was in near perfect tune when I rode it. I would say he better leave it at it ...

Thanks for the inputs i am using those bellys coz i am not able to find a 26mm pvc pipe belive me i stop at every hardware shop i see, the entire yediyur lake area doesn't have it so i am using these bellies, once i get through i will defenetly fix it on.

Teji you had taken a spin on my bike did you feel the top end lack

its the same set up since you rode last time.

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