vashishth

Hi

I have a RTR 160 since July 2009 till now it has done 16k km.
I used to get a mileage of 42-45 and a top speed I rode till was 124 kmph.
But now since past 4-5 months I have problems with the bike
1. Low mileage (30-35)
2. The bike struggles to get at 105kmph.
3. The pickup is also not so good as it was before

Till now any mod done by me to the bike is that I changed the front sprocket from 13 teeth to pulsar 15 teeth.
But that should increase the top end and the mileage (at least that is what I thought till now)
But after seeing no change in both I put back the stock 13T sprocket back where is should be.

The service center guys have same solution to all the above problems i.e. take a screw driver and play with the carburetor pilot jet screw.

I am really surprised when I read about people telling that they get a mileage of 50 kmpl.

So now I think to give up going to the service center and help me myself with this problem.
For that I need some direction from some experienced folks.

Could you tell me any problem areas to look for?

Thanks in Advance
Sapan

ken cool

Hello Vashisth/Sapan. First of all Welcome to xBhp.

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Puneet1

change spark plug and air filter if it has never been changed . spark plugs should be changed approx every 12000 kms .

If screw on carb has been messed around with ,then change it back to stock setting which is approx 3.5 full revolutions from fully closed position . it is the small screw thats horizontal on the carb , the upside down vertical one is used to set the idle rpm .

also make sure rear tire moves freely while on center stand , sometimes brakes can get engaged lightly also if they are set improperly .

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psr

Vashisth from what you are telling it seems like the Air Filter is clogged.Take out your spark plug and see the color of the center electrode. It should be TAN color..if it has dry black soot on it ,you are running rich .If it is wet black coating you have oil coming into the combustion chamber.It could be through the rings or through Valve stem seals.If you have warranty,Please go to the A.S.S, if not to any knowledgeable mechanic and ,they will be able to solve the problem.If you haven't changed the plug yet,it is time to do it.

vashishth

Hi Puneet , Psr

Thanks for useful replies
I did change my spark plug and air filter, (bought it from the A.S.S. ) and set the pilot jet screw to 3.5 rotations.

Results:
1. mileage problem is solved , I got 42kmpl as per the last test.
2. Pickup has improved significantly (not as before but much better)

Still I am not able to cross the 105 kmph limit. I only doubt the main jet to be the cause of this . So I am planning to change it too just to confirm the problem.

Please suggest

psr

I hope you haven't changed the main jet before...so no need to change it now.What was the color of the Old Spark plug center?...after changing and riding on a new plug ,what is it now ? Try adjusting the AFR screw by0.5 turns till you get the top speed right.

vashishth

No I haven't till now.
The spark plug color was dark brown color without any oil, and new one is still new so it is little bit brown yet but no oil on this one too


I will try that, but afaik at higher rpm's the main jet is in control; and if it gives more fuel to the engine than the top end is reduced ...

I would like to change the main jet; just for trying it


Thanks
Sapan

psr

Your plug indicates correct AFR and no oil leak into the combustion chamber.If you get more petrol at higher RPM the engine will continue to rev more.Your plug does not indicate a rich AFR...so don't have to change main jet....plus as stock your bike did reach higher speed.Please check if the RPM is rising, but not the speed..If it is so then you have to check your clutch plates.

vashishth

Yes, you are right . The bike did get higher speeds, I think the idea to change the main jet is not that good

I will confirm that but I think that is not happening.

Thanks a lot
Sapan

nox2505

Do check the valve clearances. Factory spec is 0.06 and 0.08. But if you run under high stress, go for 0.07 and 0.1. This will give slightly lower top speed but better acceleration and red lining.

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