Tech - Merc 500

[Tom P]

I own a 1985, 50hp Mercury 500, serial number A131168. It?s a 4 cylinder motor, with a coil for each cylinder. I installed a Telflex Value Series tachometer, part number 67291P, Sportsman Line. The direction don?t specifically include my 50hp, so I originally assumed All other 2 stroke models (12 poles, 6P). I?m using the cable from the control box to wire the tech.

Brown to Send
Black to GND
White to IGN
Nothing to LT for now

When I set the tech to 6P it reads 3K while idling with the muffs on. There?s NO Way the motor is idling at 3k. That would be cruzing speed. If I put the boat in the water and knock it just in gear I?d be doing maybe 5 knots in a 13? Whaler. I switched the setting on the tech to 2P/4C and the tech reads 1.6K at idle with the muffs on. To me, that actually reads what the motor sounds like. It?s fast, but not screaming. The other settings available for the tech are 5P, 8C, 3P/6C.

1. Is 2P/4C the correct setting for my motor? (Why)
2. My local Merc marina told if that for a motor that old, out of the water, anything under 1K at idle is ok. Any opinions on that?

 

[TriadSteeler]

Re: Tech - Merc 500

1k is the absolute upper limit on idle RPM. Ideally you'd want to be from 7-8 hundred in neutral and 5-6 hundred in gear.

Try to get it as low as your reeds will allow.

Check out the Timing and Sync Thread in the FAQ forum. Clamscanino has some really good info on how to perfectly tune your motor with respect to timing advance and carb idle setting.

 

[Tom P]

Re: Tech - Merc 500

Any takers on the Tech setting?

Tom

 

[diaric]

Re: Tech - Merc 500

you should be idleing about 700-900 with muffs, unless your idle is set way high, it will slow down in the lake from exhaust back pressure. try the 8c setting which is 4 pole for that tach. i woulda thought the 6 pole would have been correct. another thread along the same lines, they had to run a wire from the rectifyer on the engine, instead of the of the control box

 

[Tom P]

Re: Tech - Merc 500

Thanks - I'm heading out Fri or Sat. I'll try the 8P. I'm going ti try to call Telflex Friday durring the day. I've just been to busy during day light. Has anyone used Telflex support before?

Thank's again,

Tom

 

[diaric]

Re: Tech - Merc 500

when i couldn't figure out my faria one, i emailed them, got an answer the next day