Expert: tyler boehner - 2/18/2008

Question
Hello. I have a 1989 140 johnson vro with the oil disconnected. the problem is at full throttle it will cut out for a second then go again. it will not die completely just cut out. I have change both fuel filters. but it still happens. It starts and idles great. and trolls without a problem and even seems to go fine at half throttle without cutting out any suggestions are greatly appreciated thanks

Answer
Does it cut out all of the sudden like it is loosing spark then regain it suddenly again, or is it just loosing power due to lack of gas.  It may be tricky, but if you could figure out if it is loosing spark at high speed, you may have a power pack or trigger issue. If it is gas, check your fuel lines and make sure you don't have an air leak.  You can do this by putting a clear piece of fuel line in and watching it for bubbles as the motor is running.  Last thing to look at is the high speed side of your carbs may be plugged up.  To eleminate the fuel pump as the problem, simply get someone to squeeze the primer bulb and keep it tight as you run full throttle and see if it still cuts out.  If it doesn't, probably have a weak pump.