Re: fouling plug
Wild Wolf<br />You do not say what brand engine you have so do not know what type ingition you have. To start with a volt meter reads volts not amps. If it reading 10 volts that is way too low should be at least 13.8 volts with the engine running. A 90's model 35 HP could have straight points and condenser in which case the voltage would make no difference. More likely it has some form of cd ingition or a power pack and then the voltage that low could really affect the spark and cause the plug to foul.<br />In general I think 4 things cause plugs to foul. Low compression, (should be 100 to 140), Motor running cold, (Thermostat stuck open), Motor running too rich (Carbrator float too high) or weak spark.<br />I would do a compression check first then will have a good idea of rings, next I would start it up in a tank if you can or with ear muff and let it warm up. You should not be able to hold finger on motor for more than two to three seconds. Third I would start it up and run at fast idel and pull one spark plug wire off at a time. Should get a good strong spark to block of at least a half inch. This will also tell you if one cylinder is weaker than the other. Use insulated pliers so you do not get zapped. If all that looks ok then I would pull carb and clean all jets and passages, check the float level and check the needle valve and seat.<br />With the info you have given you could just have a bad alternator and a weak battery causing a weak spark. I would also check the battery voltage with another meter to make sure the ten volts is not just a guage problem. Some motors use the alternator stator to provide voltage to the power packs to insure a good spark.<br />Check the basic areas and report back with Brand and model and what you found and I am sure someone can help you.
