My bike is running very rich at the moment. I've had the carbs cleaned out but I can't find the mixture screw. What does it look like and where is it? 1988 fzr250 2kr.
The carbs only have an idle mixture screw. If you bike is running rich all through the rev range you should check things like float heights, ovaled out emulsion tubes and clip position on your needles. I wish it was as simple as turning a screw but it isn’t.
There's a fair few things your gonna need to go through to get it running well, and as with all FZR's the major thing is the carbs. BUT before we go playing with carbs it may be simpler than you'd expect. 1. Air filter If you don't know where the air filter is then chances are it needs replacing. (BTW, it's underneath the fuel tank ) An old air filter will reduce the amount of air able to get into the engine and cause the bike to run horribly rich. Inspect the air filter and if it's anything other than spotless, replace it. Many mechanics just spray it with compressed air in the reverse direction to normal air flow, but you can quite easily replace the paper filter with a foam element for less than $20. 2. Clean the carbs I know you said you'd already done this, but since i'm writing this up... i might as well do it properly. Clean the carbs with carb cleaner (or petrol), and when you think their immaculate... clean them again. 3. Carb balance If their out of sync, again it'll run very badly and chew through fuel. 4. Needles and emulsion tubes In most old FZR's, their pretty worn out. My needles have a bit of wear and tear on them, but their ok. My bike runs well... and as such i haven't bothered/needed to replace them yet.
The needles and co and worn, but not badly. I haven't had the carbs balanced as the local shop want to charge a fortune, but I see there is a method on this site. I'll have a look at the airfilter tommorow, it's actually in front of the fuel tank underneath the tank cover <!-- s --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s --> .
Ok, ok... 2KR owner You and your round airfilter. 'Ze air feelter is round!' 'Ze air feelter is FLAT!'
Paper air filters work at best filtering efficiency when they have a bit of crud in them. Problem is too much crud, it will filter air better than ever but airflow will drop off. Cleaning a paper air filter is also not recommended by any manufacturers, it can separate the filter material and put tiny tiny holes in it that will let small particles into the engine. Just change it once it has changed form a white to a definite brown colour.
