Merc 3.9HP Overheats & Stalls-PLEASE HELP!

[kandemar17]

I know very little about outboard motor repairs. I have a 1964 Mercury 3.9hp outboard motor. Model 39 & S/N 1698270. Starts fine, then heats up and stalls. Then difficult to start again, once it becomes really hot. Otherwise, it runs a short time and then quits. Entire exterior becomes way too hot to touch. I have read a few messages regarding thermostats, impellers and water pumps. Where do I start to diagnose my problem and do I have all of these parts on this antique motor? Can I do the repairs myself or do I need an expert? I am mechanically inclined. I just don't know much about outboards. Willing to buy a manual if necessary. Let me know if there is a manual I should get? Thanks and PLEASE HELP!

 

[bill giffear]

Re: Merc 3.9HP Overheats & Stalls-PLEASE HELP!

KANDERMAR17,you can order a service manual from this web site or any good marine repair shop.<br />sounds like your water pump is shot ,don't run that engine any more or you"ll burn it up<br /><br /> bill

 

[Bear]

Re: Merc 3.9HP Overheats & Stalls-PLEASE HELP!

This is for larger Mercurys but you'll get the idea:<br /> http://www.brokeboats.com/newpump.html <br /><br />Read this too:<br /> http://www.brokeboats.com/cooling.html <br /><br />The best thing is to get a manual.<br /><br />/Bear