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115HP Johnson Timing

E

edloh

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" Hello Joe,

My engines ar


" Hello Joe,

My engines are coming along slow and steady...... i came to the point where the factory manual talks about adjusting timing on the engines. it says to place the controls in the start position and the timing should be 4-6 deg. advance. i do not have the standards controls ( twin engines) so there is no start position. can i use the start mark on the throttle plate instead? at what point would spark advance start to take place?


also, it says to check the engine with a wheel at 4500 rpm and the timing should be XX BTDC (can't remember off hand). anyway, i don't have a test wheel. can i manually move the spark advace lever to simulate this condition? i am afraid of doing so at it may cause preignition and blow the engine. any suggestions? "
 
"Ed.... Good to hear from you

"Ed.... Good to hear from you again. That low end timing you speak of pertains to the cam with the scribe mark and it's releation to exactly when it contacts the center of the carburetor roller. Don't be concerned about that unless you made radical changes to the linkages etc. At any rate, that's something you can always go into at a later date if need be. For now, just be sure that the cam scribe mark aligns with the center of the carb roller when the throttle butterfies start to open.

The full spark advance can be adjusted without have the engine running at near full throttle as follows.

To set the timing on that 115hp Evinrude, have the s/plugs out, and have the throttle at full, set that timer base under the flywheel tight against the rubber stop on the end of the full spark timer advance stop screw (wire it against that stop if necessary).

Rig a spark tester and have the spark gap set to 7/16". Hook up the timing light to the #1 plug wire. Crank the engine over and set the spark advance to 4° less than what the engine calls for.

I don't know full spark advance setting your engine calls for, but to pick a figure, say your engine calls for 28°, set the timing at 24°. The reasoning for the 4° difference is that when the engine is actually running, due to the nature of the solid state ignition componets, the engine gains the extra 4°.

If you set the engine to its true setting at cranking speed, when running it will advance beyond its limit by 4° which will set up pre-ignition causing guaranteed piston damage! You don't want that to take place.

As I mentioned above, no need to be concerned about the idle timing as that will take care of itself. The main concern is the full advance setting.

Be sure to use your own engines spark advance settings, not the one I picked out of the air here in my notes.

Joe
"
 
" Joe,

Thanks you for the


" Joe,

Thanks you for the tip. this is definately easier and safer. what would i do without you?? "
 
" What is the normal operating

" What is the normal operating temperature range for an Evinrude 88 specail, 1995 model. My engine seems to operate at close to 180 degreess when it is run hard at 5,000 to 5,200 RPM "
 
" I have a boat with a chevy 3

" I have a boat with a chevy 350 in it. The motor is bored .030 all marine setup, about 9.0:1 compression. There is a marine holley 650 cfm carb on it. My question is what should the timing be at wide open throttle??? My base timing is 8 degrees btdc. It runs great but my max rpm under load is only 3400, it should run up around 4800. It will rev up higher then 3400 out of gear.

I know it is not the prop because I can't buy a prop with a smaller pitch then what is on the boat now 14X14. The boat is a 21' bayliner weekender.

If anyone knows the full advance setting please write me back. If anyone has an idea that it could be due to something else other than timing please let me know.

Thank you,

Bob "
 
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