67 merc 500 plugged tattle tale revisited

[Rayzor]

So I have been messing with this new to me 1967 Merc 500 for a month now. Got it bolted on the boat and it starts and runs fine. No water was coming from the tattle tale while running in a barrel so I changed the impellar. Well that did not help matters as still no water. It tried wire, weed wacker line, air etc to try and get threw the plug but no luck. It would seem its behind the plastic fitting on the lower port side of the block. No easy way to get at it short of removing power head, and that would be pushing my mechanical abilities. So is there some place I can plumb into or D/T a spot to get a water stream from? If not...How can I tell my motor is pumping water. Is the spray and water drops coming out of the upper exhaust an indicator? I can run in the barrel for 20-30 minutes and the head is just warm to the touch. Any ideas welcome.

 

[GA_Boater]

Re: 67 merc 500 plugged tattle tale revisited

Don't know about your '67, but my '66 500 had a plug on top and no tell-tell from the factory. I removed the plug, added a fitting and ran the hose down to the existing tell-tell fitting on the starboard. Look for a plug on the top, port side just in front on the rear motor support bracket. Hope this helps.

 

[oldman570]

Re: 67 merc 500 plugged tattle tale revisited

If the motor was run for twenty minuts and you could hold your hand on the head, then the water pump must be working. You can take the hose off the fitting for the tell tail and see if you can get it out of the exhaust cover plate to see if the blockage is in that fitting or just remove the exhaust cover plate itself. Be very careful as the bolts are probly frosen and will take quite some work to remove them without braking them. If they brake off your troubles will be 100 times worse. You can use a air hose and blow back thru the tell tail and maybe disloge what is causing the blockage, which I would do next before trying to remove the fitting or plate. There could be dried up dirt, salt or oldimpeller fin part causing the blockage. Seeing how the motor is spitting water out the exhaust ports on the rear of the motor and it is not overheating the trouble has to be at the fitting or just inside where it goes thru the cover plate. JMO
Oldman570

 

[Rayzor]

Re: 67 merc 500 plugged tattle tale revisited

Don't know about your '67, but my '66 500 had a plug on top and no tell-tell from the factory. I removed the plug, added a fitting and ran the hose down to the existing tell-tell fitting on the starboard. Look for a plug on the top, port side just in front on the rear motor support bracket. Hope this helps.

I found a plug, has a flat screw slot plug inthe top. So if I remove that and water comes flying out im good?

 

[GA_Boater]

Re: 67 merc 500 plugged tattle tale revisited

I found a plug, has a flat screw slot plug inthe top. So if I remove that and water comes flying out im good?

I'd say you found it. Be careful on the hose routing. I originally ran it close to the flywheel and it chewed a little on it. Moved it so it was sort of over front facing edge of the rear bracket and no problem with flywheel interference. Mine pees like a race horse.

 

[Rayzor]

Re: 67 merc 500 plugged tattle tale revisited

Great info, I plumbed a line there and its flowing water great. Thanks for all the help! I used some epoxy to cap off the original fitting just incase it blows open going over water. Now, if I could just go fishin....