rd500 yamaha

[Guest]

does anyone know why my rd500 runs on 2 cylinders only. i've changed the coil and plugs to no avail.thanks (desperate)

[Guest]

are you getting sparks on all 4 plugs,

if so the plugs and coils are ok,

if not, have you got power to the coils.. check with a multi meter, if there is power going into the coils, swap the working plugs over into the on working ones, and try again

this will eliminate plugs, so will be the coils, to eliminate the coils swap over and the fault if the coil will migrate to the other side, if it stays the coil is fine and its the electrics..

if theres no power to the coils work back.....

[Guest]

thanks walney frankie, i will try that this weekend if the weather holds.

[Chrissb6]

Quick test, whip out the plugs and rest them in there leads against the the engine casing turn the engine over and see if there's a spark at the plugs, trace fault back if you have any plugs with no spark, this is a quick way to check the plugs. If these are all working ok you might have a fuel problem, check the fuel strainer in the fuel tap to see if any of the fuel lines are blocked.

Hope you find a simple cure.

[Guest]

thanx chrissb6 will do

[Guest]

have tested plugs, all 4 have a spark,any more suggestions if fuel tap ok?

[Guest]

have tested plugs, all 4 have a spark,any more suggestions if fuel tap ok?

its doubtfull that your getting fuel to 2 and not the other 2 from the tap, must be a blockage on the lines to the 2nd bank of carbs, or a carb issue.

[Chrissb6]

Well if you've got sparks my friend next step is to check the fuel system.

Just looking at this web site below, l note that the fuel lines are coupled to the carbs each side of the of the engine. Next step, I would turn off the fuel tap and remove the fuel line at each carbs then open the tap and see if the the fuel is getting to each carb.

If the fuel is there at each of the carbs then, l would suggest putting it all back together and try and start the motor on the 2 working pots for a short moment, feel for the exhaust getting warm you will then know which cylinders are giving you trouble. You might then want to have to have a look inside the carbs and check the floats. Its just one step at a time till you find it. Best of luck mate.

http://www.racingsm.org/evo500.php

Some good pic's here

[Guest]

thanks for all your suggestions i will try them all and hope for the best. watch this space!!