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1971 Mercury thunderbolt 500 help needed

L

Longtrain

New member
My buddy picked up a 1971 Mercury Thunderbolt 500 outboard in pretty fair shape. The engine runs smoothly, however the throttle does not increase the engine speed until the lever is at about 12 o'clock, at "full" throttle it runs probably at 1/3 of expected speed. Adjusting the gross throttle adjustment under the cowal a bit allowed higher speeds, but the idle increased also. It appears possibly that the throttle cable is not allowing the engine to adjust to higher speeds. If this sounds plausible, can and how is the cable adjusted to allow full range of operation.

This and any other info is greatly appreciated.

Greg
 
is the timing advancing?do you have a distributor?if so it has a grease fitting on it and turns to advance timeing..they get hung up...
 
papyson said:
is the timing advancing?do you have a distributor?if so it has a grease fitting on it and turns to advance timeing..they get hung up...
Click to expand...

I believe so, yes, there is a distributor, with the cowel off you can actually physically move the distributor and increase the engine speed, it seems to move freely, from a low idle to quite fast, it doesn't seem to be hung up. But it does not have that range of motion via the throttle cable. Moving the throttle does not move the distributor for at least half of its travel.
 
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kimcrwbr1 said:
http://www.maxrules.com/oldmercs/Wiring/1966ona/26A.jpg
Does it have the 7 pin connector on the motor for the harness?
Click to expand...

I'm checking with my buddy, serial #2741917 with MerControl, if that helps.

Via the magic of the Internet he sent this photo.
image.jpg

Thank you for all your help, much appreciated!
 
kimcrwbr1 said:
Is the throttle and the shift cables reversed at the motor? Pull both cables at the motor and put the handle straight up the first cable to move is the shift cable either forward or reverse. Push the warm up lever all the way down and then put the motor in neutral and the throttle to the slow position then connect the cable and adjust as necessary.
Click to expand...

Ok, we'll take a look at that...thanks. Although, I doubt they are reversed there, this motor was purchased with a boat, all connected.
 
Pdanno..he didn't get back to us on the fix so I doubt if he will answer you...you need to start another problem entry..
 
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