Re: RXG 135. Looking for help with modifications - engine and cosmetics

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Re: RXG 135. Looking for help with modifications - engine and cosmetics


If the bore is in last stage, keep using it until it gives away then purchase a new bore
Check the compression of the engine as you are saying the bore is almost a gonner case so tha's why the bike is not able to cross 70km, but still get it tuned properly.
But the average you are mentioning is quite fine i would say for this kind of engine.
Start your bike with help of the choke in the morning, keep the engine in idle state for 2min. and then ride.
Go for original rear shocks they are the best.

I would say (purely my choice thoug) don't spoil the looks of this beautiful bike by converting it to cafe racer infact keep it stock that where the bike looks best. I don't think you should convert the bike to 6 speed you won't find any special gaines plus the original 6 speed gb from malaysia will cost you fortune, one of my friend just inquired about the genuine and iam saying Genuine 6spec Gb and it was costing shocking 26000/- rs.

Crankcase and cylinder porting of an 2stroke engine is very complicated and debatable subject, the person who is porting the engine must fully understand the behaviour of the airflow in the engine, how does the air moves inside the engine, under the piston, around the sides,how to make intake tract smooth for better air flow(something related to CFD) the other part is of air density, which gets changed from time to time in summer it will be different and in winters it will be different plust the Elevation changes. A mandatory squish test is required plus the compression test, accurate and precise measurements, like width, height and radius are required, so all of this porting requires tremendous knowledge plus the computerised evaluation system which iam afraid to say is not available but if you can find someone who has the skill plus the necessary equipments then you can give this a try.

Re: RXG 135. Looking for help with modifications - engine and cosmetics

Thanks for the detailed and extensive reply. I really appreciate it.

The tuning I believe is done quite well by the mechanic now. What is the compression of the engine dependant on? Is it the bore and the piston? Will the bore being in the last size make a difference to the compression rate of the engine?

The average, honestly is more than what I expect(ed). The engine starts properly in the morning if i leave in on centre stand. The leaking (of oil+petrol) is still happening if left on side stand - what could be the reason?

You are right about teh cost of 6 speed gb. I can get it done for 20k including mechanic cost. Do you think refurbishing the engine with new bore and piston and cleaning the crankcase will give me almost the same performance as if I convert to a 6 sp gb?

I understand where you are coming from, regarding keeping it stock. I respect it and will definitely consider keeping it stock

Re: RXG 135. Looking for help with modifications - engine and cosmetics

Am I missing something here?? 6sp gb? When did the rx come with a 6sp gb???

Regarding the looks, I agree with kush, a little mod here n there is ok. But converting to a cafe racer, without proper tinkering knowledge can be disasterous. Take it from someone who had done it before.

Compression depends on several factors, quality of boring, quality and condition of the rings, condition of the block liner etc. So check it one by one. Most likely it is due to bad rings and wrong boring.

Regarding the leak, change your your bowl gasket and float pin. Check the floaters. Clean the carb throughly. That should solve the issue.

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Re: RXG 135. Looking for help with modifications - engine and cosmetics

Hi Bibhu, 6S is Malaysian spec.
And as per my understanding 6S isn't a bolt on fitting like our 5S GB (Crankcase also to be changed, I suppose)

Re: RXG 135. Looking for help with modifications - engine and cosmetics

if you are still interested in converting it to a cafe racer then visit the foll link ,it has almost all details in converting an rx into one :My Yamaha RX100 Cafe Racer modification thread! Dec 09 - back to stock! - Page 14 - Team-BHP

as for porting in the indian sense involves raising the height of the exhaust port (basically making the exhaust port bigger by grinding away metal from its upper areas) , the remaining transfer ports are usually left un molested as none of the so called tooners have the know-how, expertise or tools to modify the transfers accordingly to match the exhaust port.
advantages: your power out put will increase ,and the bike will become rev happy
Disadvantages: your mileage and engine life will be drastically reduced, low end pulling power (torque) will be reduced

as for the 6 gear set up , unless you intent to go out all out track racing with an all out ported set up, the 6 speed set up is useless , , better you go for the 5speed set up as it is best suited for indian conditions and would set you back only a fraction of what you are quoted for the 6speed one ,and you can invest the money saved into a front disc set up or better lighting setup or cdi unit

Re: RXG 135. Looking for help with modifications - engine and cosmetics

If you are talking about the rxz 6sp, It is derived from the brazilian rd125 and doesn't belong in the rx family per say. The gearbox from rxz 6sp is not a straight fit in our rx. Infact I am yet to see a properly converted one running on streets.

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Re: RXG 135. Looking for help with modifications - engine and cosmetics

Because of the proper tuning by your mechanic you are getting this 40km/l average, if your compression is near about some 120psi i will say its very good at this stage of the engine
The leaking of petrol can occur from carb, get it checked as Bhibu said, for oil leakage, open your bikes left side outer cover, clean it properly from inside, if the leaking oil is black in colour then most probably it's the extra oil from chain which is dripping,but if the colour oil is like your transmission oil than get your bike's drive sprocket seal which sits behind the drive sprocket

Every Yamaha rx version is very basic and very easy to work on that was the beauty of this vehicle becuase of which bike's is loved so much even today, just keep it simple that was the basic mantra of the bike, if your mechanic is competent enough then refurbishing the engine is no issue at all, obviously the whole engine, the crankcase should be thoroughly clean with degreaser and then should be pressure washed, Yes Yes it will give you the performance of a new bike no doubt.

Thank's for considering my suggestion of keeping bike in stock condition, you will yourself realise that keeping the bike in stock condition is the best decision you took.

Re: RXG 135. Looking for help with modifications - engine and cosmetics

"[QUOTE=kb100;1065628]"
"[QUOTE=kusmaker;1065636]"

Thanks folks for the replies.

So here is where I am at -

1) I will go for a 5s GB, hopefully try and import it from malaysia. How much should this ideally cost including labour ?
2) No modification. Stock is good
3) Leaking is still happening. It is petrol+oil, even ,more when the bike is on side stand. No leaking when fuel is turned off
4) Starting trouble still exists, only when the bike is left on side stand.

​Any views?

Re: RXG 135. Looking for help with modifications - engine and cosmetics

[QUOTE=kishorenkumar;1066298]"[QUOTE=kb100;1065628]"
"try and get an oe gearbox kit from here itself, will work out cheaper
as for the leak your carburetor needle valve is probably worn out get it replaced , also check the idle screw o ring also for damage.and replace
this should solve your starting issues also

Re: RXG 135. Looking for help with modifications - engine and cosmetics

[QUOTE=kishorenkumar;1066298]"[QUOTE=kb100;1065628]"
"
Get your carburetor float checked, i believe your carburetor is over flooding, check your carburetor float for bends and improper adjustment,do you feel smell of petrol when the bike is in idle state.