spike22 Posted August 31, 2008 Share Posted August 31, 2008 Hi I recently purchased a YB 100 1987. Seems to use alot pf petrol, about 70 miles to a tank, uses very little 2 stroke. I have checked the air filter and it is very clean and a little oily, no sign of any splits around the intake. Checked the plug and is a bit black and sooty indicating a rich mixture. Thinking about investigating the carb, it looks like the cover has been removed many times in the past. Would like to have some advice on the carb, how do you know when it is worn, is it worth replacing, can you get reconditioned carbs, are the carb kits any good. In short I know very little about carburetters and I'm looking for help. Many Thanks Spike22 Link to comment Share on other sites More sharing options...
JimR Posted September 7, 2008 Share Posted September 7, 2008 Hi I recently purchased a YB 100 1987. Seems to use alot pf petrol, about 70 miles to a tank, uses very little 2 stroke. I have checked the air filter and it is very clean and a little oily, no sign of any splits around the intake. Checked the plug and is a bit black and sooty indicating a rich mixture. Thinking about investigating the carb, it looks like the cover has been removed many times in the past. Would like to have some advice on the carb, how do you know when it is worn, is it worth replacing, can you get reconditioned carbs, are the carb kits any good. In short I know very little about carburetters and I'm looking for help. Many Thanks Spike22 Hi Spike22, Yb100 carb is simple to work on after the case is removed 1 screw & a couple of pipes and its off. In the past yb's didn't give much trouble with there carbs but if you drop off the float chamber & check that the float is ok and that the valve it shuts off is working and the jets r ok and of the right size. Do you turn fuel off when the bike is stoped? If not you may be loosing a bit of fuel thro the overflow pipes. While the cover is off its good practice to set the oil pump up. Do the following, with the carb cover off start the motor and watch the pump move in & out then stop the engine the pump at its furthest point out. Check the cable is adjusted correctly then measure the gap between the washer on the pump and the grey plastic wheel the cable lives in (you will see a high spot on the grey wheel measure there). I cannot remember the clearance so a Yam dealer will be able to suplly with that, if correct the oil pump is the set up, if not remove the washer & fit or remove shims as required. Back to the carb, while its off check the needle is in the correct clip position and that the slide is not worn. Air filter you mention its oilly, this should be so but only just so take it out and give it a good squeze just in case someone b4 you over oiled it. Regards mJim Link to comment Share on other sites More sharing options...
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