Yamaha YBR 125 hard starting

SOURCE: What are the valve clearances of the engine of

Valve clearances are
in 0,12 mm
ex 0,15 mm
on cold engine

SOURCE: yamaha ybr 125 top speed

Hi les
Not much to start with here unfortunatly mate. A free flow muffler will help top end speed, change the factory airbox to a K&N style pod air filter, other than that, hugging the tank at top speed :) If you do change these parts, you may also need to increase the main jet size to richen up the mixture for better tuning of the motor with the better flowing parts. This bike has a top speed of 100kmp and produces 10 hp, so you may only expect to get at best less than 1 extra neddy, and perhaps another 5 km/hr.... I suggest upgrading to a bigger machine of you feel the need for speed :)
If its 125's you are into, test drive a Honda CBR 125R 6 speed fuel injected 13.4 horsepower, and good for 120km/hr
regards robotek

SOURCE: Engine cutting out when open throttle. YAMAHA NEOS 50cc MOPED

i had a simuler problem with my honda cr 250 moto-x bike it would start fine and you could keep it ticking over with the throttle(i have deliberatly unscrewed the tickover in case i come off,it will cut out) when i got on it,it would go for about 400-500 metres then splutter and die and not start again for around 5 mins. i immediatly knew it was a fueling problem. so after stripping the carb and giving it a good clean out i was baffled when i got back on and it still done the same. i then dismantled the fuel tap cleaned it all out and put it back together and tested it,it was very very slow so i unsrewed my fuel cap a little and was greated with the familur gush it should deliver. problem solved! the vent in my fuel cap had crystalised up,so the fuel was coming out but the air was not getting in,causing a vacuum and slowing down the flow and basically emptying the carb quicker than it can fill back up!!! clean your carb,fuel tap and any vents in your cap or tank. if this does not work then your bike must be over fueling or low on compression.

SOURCE: 2002 yamaha 650 vstar, 20,000 miles. it won't

Could be the coil. Also could be several other things. Download a shop manual and diagnose it.

SOURCE: Yamaha 2001 ttr 250. Bogs above half speed, under load

I have the same problems with my 1999 TTR 250, were you able to find out anything?

Walt
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