I have a Yamaha Nouvo 135 about 7-8 ys old but served me very very well but now when i give it full throttle and increase speed it stutters and not so much power.

I have to go to 50-60% and then gradually increase the throttle.

 

Any ides what could be wrong. Trying to explain to thai is not so easy.

Carb or FI ?

How many kms on the belt? 

1 hour ago, canthai55 said:

Carb or FI ?

I know nothing about bikes or engines im afraid to say.

45 minutes ago, VocalNeal said:

How many kms on the belt? 

Just coming up to 65,000

 

Any recommendations

I'm thinking that if you haven't changed the belt then it has worn thin. So the engine revs up and the transmission does it's thing but because the belt is thin you are not getting sufficient drive and the engine revs increase until the rev limiter cuts in.

 

That OR the main jet in the carburettor is clogged and there is insufficient fuel at full throttle. If willing you can buy a bottle (from Tesco/BigC/etc. automotive section ) of fuel system cleaner and bung the correct proportion into the gas tank and see if that clears it up.

 

Or it might simply be that the fuel filter is all plugged up. Same symptoms as the main jet. Ie. Fuel starvation.

 

Take it to Yamaha and if you can't explain in your best pantomime Thai ask the mechanic to take it for a ride with emphasis on the full throttle wrist position :-) 

If you don't even know the basics it's impossible to help you here

Take somebody who can translate for you with you to a mechanic? Then you can explain it and he can have a look

+1 vote for the carburetor issue, needs cleaning/repair....  

#1 - replace spark plug

KISS - first rule of troubleshooting.

2 hours ago, VocalNeal said:

I'm thinking that if you haven't changed the belt then it has worn thin. So the engine revs up and the transmission does it's thing but because the belt is thin you are not getting sufficient drive and the engine revs increase until the rev limiter cuts in.

 

That OR the main jet in the carburettor is clogged and there is insufficient fuel at full throttle. If willing you can buy a bottle (from Tesco/BigC/etc. automotive section ) of fuel system cleaner and bung the correct proportion into the gas tank and see if that clears it up.

 

Or it might simply be that the fuel filter is all plugged up. Same symptoms as the main jet. Ie. Fuel starvation.

 

Take it to Yamaha and if you can't explain in your best pantomime Thai ask the mechanic to take it for a ride with emphasis on the full throttle wrist position :-) 

Thats it.

I have a Nouvo Elegance 135cc, great little bike, probably the same as yours. I take it to a little motorbike shop in Bangsare every year for a service, they check all and change all oils etc for a few hundred baht, it's not worth the effort of gettin your hands dirty.

Probably your carb, I don't believe they did FI (fuel injection) on that model, could be quite a few things, take it to a small bike shop, one on reconmendation if possible, they will tell you immediately I should imagine.

15 hours ago, canthai55 said:

#1 - replace spark plug

KISS - first rule of troubleshooting.

Agree. 

 

Actual first rule of troubleshooting? = What has changed.

Thanks for advice guys will take it down to Yamaha dealer when next time if off work.

 

My 2010 Nouvo 135 has a carb and if I don't ride it for a week or two it is hard to start and if I don't let it idle for awhile, it will not accelerate when given throttle.  It just bogs down.  However, once warm, it runs great.  I have only 9,000 km on the bike and  I have it serviced annually.  I have heard that this is common with this carburated model.