91 rm125 bogs down on acceleration,changed spark plug,cleaned carberator,replaced air filter.?

Question

91 rm125 bogs down on acceleration,changed spark plug,cleaned carberator,replaced air filter.?

Answer 1

When you say you cleaned the carburetor does this mean you opened it up cleaned out the float bowl and fuel jets? How old is your bike?Has it sit for weeks or months unused at any time?If yes heres the possible problem.Gasoline will turn to a brown syrup like mixture after it sits for 3 or 4 months or more.If this is the case this brown syrup is clugging the jets in the carburetor and likely is formed in the bottom of the float bowl inside the carburetor and also in the bottom of the fuel tank.Replacing the fuel  will not remove the brown syrup mixture.You must find the drain valve in your owners manual drain all the fuel from the carburetor and fuel tank.Then purchase 1 gallon new fuel into your gas can ,then add a liquid called C-foam,Add the correct amount for 1 gallon of fuel,you will find this at your local auto store..Now pure the gallon of fuel into your fuel tank.Let it sit for an hour,this will give the c-foam time to melt the brown syrup that has built up in your carburetor and fuel tank.Then start the bike.The exaust will be kind of smokey intell all the c-foam is burned off.This is normal.You can also confirm this problem removing the air filter and spraying starting fluid or wd 40 in the intake of the carburetor.If the engine will start and run for a few seconds.This confirms your ignition is working fine and there is a lack of fuel do to the brown syrup mixture blocking the fuel flow to the carburetor.. Best of luck!

Answer 2

it depends...It could be you have old gas. Maybe needs new oil..or i could have something like dirt or water inthe motor, but you said you cleaned the carborator so its probably the oil or gas...If its not gas most likely the oil.

Answer 3

Some great answers so far..all are pretty much on point and you should try them.

One thing I will add, there should be a rubber boot running from your airbox to your carb...make sure that boot is connected on both ends, should be either compression clamps or maybe hose clamps.  If either side comes loose you get too much air..the bike would idle fine and ride ok at low RPMs, but as soon as you tried to give a little throttle it would bog BAD.

Also check that boot for damage, if its cracked or cut it would do the same thing.

Its something simple to check... just thought I would add it.

Answer 4

Did you just buy this bike? The reason I ask is because a bike can run differently at different altitudes (more or less oxygen). It can also run different depending on weather changes, eg temperature, humidity. If this were the case then you might have to play around with the jetting.

Answer 5

maybe bad fuel, but i am thinking bad reeds, or if it bogs out midrange and above it is time for a top end rebuild