just jot a 1972 4 hp. needs some tinkering. can you help?

[section8]

hello yall. tried my new used trolling motor today. it took about 30 pulls to get it to burp then a new plug i had kickin around fired it up. it ran for about 30 seconds then petered out tried again and it took quite a few pulls to do the same thing. i switched gas tanks and it did the same and now it doesnt wanna fire at all. the plug looks flooded. it came with a surface gap ngk buhw and the one i put in is surface gap buh8. i held the plug to the motor and the spark looked kinda weak. question 1; should i use a conventional plug? if so, any recommendations? question 2; the carb says "mercarb 1399 4664 on it. is this the right carb or was it switched somewhere? i wanna do a carb clean but not if its the wrong carb. mercury parts express and iboats shows some other ka10 and when i google it theres people with ka9 and 1399 4654 or some other #s. the #s on the fuel pump are 53240 61541 then a sideways 3 like an "m". question #3; any idea on the fuel pump diaphragm/gasket #s i need? im planning to order them from iboats but want to make sure the parts are right. should i swap out the coil while im at it? any other advice beyond that would be extremely appreciated. Thank you guys! Erik

 

[markallen72112]

Re: just jot a 1972 4 hp. needs some tinkering. can you help?

I recently obtained a 1972 model 4 hp motor as well. Luckily, after the motor sitting in a shed for 5 years without being used, the sucker started on the third pull. Took it out and it never died, and it idles like it's new. I also had to do a little tinkering on this motor. Here's what you need to start with. Check all your lines especially the gas line. The gas line on these models come as an assembly and are quite a job to replace. Next, check and make sure your motor is pumping water. The impeller may be dry rotted. Replace your spark plug. Finally, there is a fuel pump diaphragm on these models that dry rots over time and will bust apart when new gas hits it and you fire the motor up. I can almost guarantee you that it is the fuel pump diaphragm thats causing the problems. Also, I would like to add, I do not know your level of experience with outboard motors, but in my experience less is more when it comes to replacing things on outboards. The less you have to tinker with this motor the better off you will be. Good luck...