Metal rattling sound on my old Mercury 7.5 HP

Hello everyone,

I purchased an old Jon Boat last year with a 1976 Mercury 7.5 HP motor. It ran OK last year but constantly had problems with the pull string and carb. Anyways this year I cleaned out the carb real good and replaced gasket seals. I also replaced the starter rope string. The motor is idling and running pretty good now. However I noticed that when I go in full throttle I hear almost a metal clankety rattle sound coming from the motor. Its not a knocking sound or anything. It almost sounds like a piece of metal just bouncing around somewhere. Any ideas on what it might or could be? I've already taken the pull string assembly apart and put it back together again in hoping this may clear the sound, but I won't be able to test it out until this weekend. Thanks in advance!!

David

Hey thanks for getting back! That sounds like it could very well be it as it does seem like something is flopping around in there. Thanks again!

kimcrwbr1 said:

http://www.marineengine.com/parts/m...33-thru-3801457/top-cowl-and-starter-assembly
There are three small wave washers and one large one. Look close at the retainer plate you will see alot of wear where the pawls are flopping around. They are a pain to put back together correct and keep the proper tension on the return spring. When you pull on the rope the pawls extend out fully and when you release the rope the pawls shoud pull in fully. You may need a new plate but normally replacing the wave washers will tighten it up and hold the pawls fully retracted.

Click to expand...

You know what.. I don't remember seeing any wave washers under the pawls? (I assume they go under?) I'll probably just order some of those for now and see if that helps with the noise. Thanks for listing the parts for me!!!

If you want to eliminate the pull starter making that noise, fire her up, let her warm up. then shut her down and remove the recoil assembly. Wrap a rope around the flywheel and away you go. (You'll have to jumper the coils to the block.)

Jeff