easy questions 1971 Johnson 50

[Jconnell43]

1.When they say at idle your timing should be 4 degrees below top center should I be using the 4 marked on the flywheel or using the scratch mark I made on the flywheel?

2.If I have the timing correct but the cam follower and roller disconnected should the engine run or do the butterflies have to be completely closed when they are not being opened by the cam roller.

Thanks,
Jim

 

[jimmbo]

The timing is not set at idle, as the idle speed is controlled by the retardation of the timing advance there is no real spec as it will vary from engine to engine. There is often a timing spec listed for the point where the throttle linkage starts to open the carb a bit from fully closed.

 

[Jconnell43]

Then how should I adjust the rod that controls the advance.
I'm having a hard time keeping it running but when I do the timing is always around the scratch mark.
I guess I should be looking somewhere else for the reaso it's not running well?

 

[racerone]

Correct.-----Perhaps do a compression test.------My tester would show 140+ on that motor in good condition.

 

[Jconnell43]

No Title

Had the motor running for 5 minutes, trying to get slow speed idle screws set correctly and using rag to hold throttles slightly more open than usual.If I'm reading all of you correctly the timing at idle doesn't matter it only matters under load and throttle.
When I adjust the idle screw it it advances both the throttle and the timing mechanism right under the flywheel (see end of screwdriver in pic )
My question is:
What is a good initial idle setting for the timing mechanism by screwdriver, I have seen you tubes of running identical motors where it is further to the right than it is in my pic.If I am confident of that then I can get the throttles and cam roller done correctly.
Sorry about the "dumb" questions, I'm great on 40 year old BMW's.

 

[jimmbo]

What you need is the service manual. Then you will get the, initial idle mixture setting, timing specs, and how to synchronize the carbs to each other and to the ignition advance. Blindly moving this and shimming that, will only take you away from where you need to be

 

[boobie]

Agree 100%...........

 

[CaptnKingfisher]

My question is:
What is a good initial idle setting for the timing mechanism by screwdriver,

I'm just an amateur myself but I've heard people say tun the screw all the way in tight, then back it out 6 full rotations. From there you can start feeling out your fine tuning. Your manual should have an RPM spec for your low idle, I believe

 

[jbuote]

I don't have my service manual handy, but yes.. Use the manual!
​I also have a 71 50hp, and am also a "Newbie"..

​I know the full timing advance is 19 degrees. If all else is set per manual, the idle timing should pretty much take care of itself..

​As for the idle MIXTURE needle valves baseline, it's about 1-1/2 turns out from LIGHTLY seated.. (NOT all the way in tight..)
​The manual does have initial settings for the "Timing Stop" screws.. They are usually listed as "1/2 inch of threads showing on outside of bracket" type of thing.
​You'll find that when you look in the manual for the exact specs....,

​Again, I don't have my manual handy, so can't quote it, but definitely get one!
​It'll save you heartache..

​Also...
​Take heed to recerone, boobie and jimmbo.... They've never let me down yet... (As long as I paid attention...)

 

[jbuote]

OH.. And in the pic you posted, I see 2 yellow wire nuts on the wires from your main harness plug.



As far as that goes, I believe that's a big no-no with outboards...
​I'd replace those wire nuts with proper splices somehow...
​JMHO..

 

[Jconnell43]

Reason I do that is because you have to disconnect those 2 shift wires every time yo do a water pump and splicing them every time shortens the wires.
Good tip on doing something more permanent.

 

[jbuote]

Pretty sure down lower where it starts to head down to the foot, there should already be "Knife" type connectors or something so you can "unplug" the shift wires to lower the LU, and then plug them back in after you put LU back on... Maybe they were cut out on yours, but I'd think they should be there somewhere already so you don't have to cut and splice each time...
Just a thought... LOL