Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1

TOPIC: 1974 merc 85hp idiling issue

1974 merc 85hp idiling issue 14 years 7 months ago #4713

I just aquired a 1974 85 hp merc outboard it runs fine on fast idle,but will not slow idle.can someone please provide some ideas of what could be wrong.

Please Log in or Create an account to join the conversation.

Re: 1974 merc 85hp idiling issue 14 years 7 months ago #4727

Always start the trouble shooting with a compression test.

Please Log in or Create an account to join the conversation.

Re: 1974 merc 85hp idiling issue 14 years 7 months ago #4837

As mentioned, check compressions are all good then go through the carbs & fuel pump. Check timing is correct. If all this is good then there are some small plastic restrictors located in the transfer ports on cylinders 1-3. By all accounts these can work free & get ingested, after that the thing will never idle any sense.

I believe I may have the restrictor issue on my '84 115 as it won't idle any sense & everything else is done.

Please Log in or Create an account to join the conversation.

Re: 1974 merc 85hp idiling issue 14 years 7 months ago #4861

have you cleaned the cap and rotor if it has one.

Please Log in or Create an account to join the conversation.

Re: 1974 merc 85hp idiling issue 14 years 7 months ago #4870

  • g3jim
  • g3jim's Avatar
  • Offline
  • Platinum Boarder
  • Platinum Boarder
  • Posts: 1009
  • Karma: -27
  • Thank you received: 0
end cap seals?? especially the bottom seals

Please Log in or Create an account to join the conversation.

Re: 1974 merc 85hp idiling issue 14 years 7 months ago #4884

if lower seal was bad it would pull water in the lower cyl.

Please Log in or Create an account to join the conversation.

  • Page:
  • 1
Time to create page: 0.172 seconds

Donate

Please consider supporting our efforts.

Glassified Ads

1967 23 ft powercat flybridge
( / Boats)

noimage
11-17-2024

Mercury outboard
( / Engines)

noimage
11-03-2024

Classic Mercury Outboard Motors
( / Engines)

Classic Mercury Outboard Motors
10-18-2024

FG Login

FiberGoogle

Who's Online

We have 9061 guests and one member online