Search results

  1. M

    spark plug orafice size

    Anyone know the size of the spark plug orafice on a 1975 johnson 50hp? I may purchase a used compression guage to check the motor, but am not sure of the size I need. <br /><br />Thanks
  2. M

    difference is compression

    just a general question, when looking for used johnson outboard what is an acceptable difference in compression betwwen cylinders?<br />Thanks
  3. M

    any bad years for Johnson?

    After i service my lower unit,I may buy a "newer"<br />motor (1975 50 hp now)Are there any year/models that I should avoid? I am looking at a 1978 140 hp, but think it my be too heavy and too much power for my 15' starcraft. Any thoughts?
  4. M

    Lower unit seals

    Weighing whether to replace lower unit seals on my Johnson 1975 50hp myself, or to pay the shop to do the job. I have a manual, and it shows how to totally take apart the lower unit. I am curious as to how much needs to be removed to replace the seals, and if it is one of those jobs that is...
  5. M

    lower unit

    Drained the lower unit today on my '75 johnson 50 hp and found milky oil. Had same problem last year, so I made sure there was an o ring on each drain bolt. can I assume water has entered the lower unit? Does this require a whole lower unit rebuild, or just new seals? Is the job a do-it-yourself...
  6. M

    replacing axle

    HELP!! My brother was returning my boat to me on its trailer and has become disabled. 15' foot boat on a single axle dutton-lainson trailer with 2000 lb axle. He says it looks like the bearings blew out. Fortunately boat is at a rest stop parking lot. I will have to travel there to fix it. Is it...
  7. M

    need screws

    need screws for my Johnson 50 hp (1975) air silencer cover. Use to to get parts from the shad connection, but they seem to have gone out of business. Any suggestions?
  8. M

    air silencer screws

    Motor is a 1975 Johnson 50 hp. Rebuilt the carbs last fall, and lost the screws for the air silencer cover. Is the cover necessary?<br /><br />If so, are the screws a type which I could pick up at a hardware store? Or should I just reorder from online outlet.<br /><br />Thanks<br /><br />p.s...
  9. M

    lower unit question

    about to re-attach the lower unit to my '75 johnson 50hp. Npticed that when i push down on the "boot" where the shift rod enters the lower unit a small amount of water squeezes out. Does this mean water got where itshouldn't be?<br /><br />If so, what now? Rebuild!!??
  10. M

    Shift rod/lever

    OK, so i replaced the water pump on my '75 johnson 50hp. I am trying to reassemble the lower unit to the exhaust housing. I have all the lower bolts on, I go to re-attach the shift rod to the lever, and the shift rod is about 1/2" short of where the bolt goes through!? Did I do something wrong...
  11. M

    gasket sealing compounds

    I'm replacing my water pump, and the manual says to dip the screws in OMC gasket sealing compound. None came with the kit, is there a substitute I can use? How about grease? What about the "moly LUbe" packet that came with the kit for placing on the upper drive shaft splines?
  12. M

    water pump "key"

    currently replacing water pump on '75 johnson 50hp. Trying to slide new impellar down over moon shaped key on drive shaft. How hard should i have to push down on the impellar? It seems like I'm using an awful lot of force, and it won't go down. Curve of key facing center of shaft. Do I need to...
  13. M

    while i'm ordering parts...

    While I'm ordering new drain plugs/o-rings for my '75 50hp, I am considering replacing the water pump impeller, just because it's an old engine and I don't know if it's been done yet. Have an OEM manual, but it does not have specific directions for replacing this part. Is it difficult, and what...
  14. M

    grey lower unit lube

    Lube in lower unit came out a kind of grey, milky color. I assume this means water where it shouldn't be. ( '75 johnson 50 hp) Other than drain/fill screws, what are the most likely suspects? If I try to fix myself, do I need special tools, and is it a do-it-yourself project. Just rebuilt carbs...
  15. M

    carb rebuilt, thanks!

    Just finished rebuild of '75 50 hp. Motor runs great. Thanks to all who shared their knowledge. Love this BB. :D
  16. M

    leaf plates

    OK, I am rebuilding the carbs on my '75 50 hp Johnson. Carbs are off, and I am inspecting what I can see of the leaf plates. They all seem "straight" and not warped. One or two look as if there may be a "hair" size gap off the plate.(and I do mean just a hair) Is this within normal tolerance? I...
  17. M

    gasket removal

    Whats the best way to remove old gasket from the carbs? Do they make a special remover?
  18. M

    how clean should carb be?

    '75 johnson 50 hp was running very rough at low speed. Figured carbs must be gummed up, so I took 'em off and opened them up to clean and rebuild. They look pretty clean to me. Not really any varnish. My question is, how dirty do they have to be before they start to cause rough running. If not...
  19. M

    1975 50 hp gaskets

    Need to find gaskets for the air silencer on my 1975 50 hp (50esl75) There are two, one for the cover and one for the carb side. Can't seem to find them anywhere. OEM part numbers are 316051 and 316091. Is it possible to reuse or make on my own? If not, anybody know where I could find such...
  20. M

    leaf plates

    As a general rule, do the leaf plates need to be changed on a Johnson 50 hp 1975 as regular maintenance, or only if something causes them to distort or bend?<br /> How do you know when it's time to replace them.<br /><br />thanks :p
Top