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Evinrude 175 Bogs right before plane then after some tinkering takes off. (year 1977)

S

StophinHousen

New member
Hiya,
I've got a old 175 that acts up when it feels like it, it will bog down just before plane. Sometimes pushing in the key for the choke will get it to go, where other times only if I run it without the cowling will it take off, while other times it will go like a bat out of hell all on its own. The motor has decent compression at high altitude on all 6 cylinders (they are within 10 PSI) and so far Ive,

Rebuilt carbs,
rebuilt fuel lines,
replaced fuel pumps,
replaced primer bulb and hoses,
replaced plugs and one coil,
replaced rectifier,
replaced intake manifold gasket

I've played with timing some but I honestly don't know if I have my numbers right as Sealoc doesn't have anything for 1977, and I don't know if I have my carb pick up adjustments right either.

I'm thinking maybe my timing is too far Retarded ? I've got it set to 26* BTDC as its max but it maxes out really quickly and I'm not sure that is enough. Or I'm still missing a fuel issue somewhere and its running lean until it gets just the right amount of vacuum. OR my 25:1 break in oil was too much and bogged down the motor (ive since added some 50:1 to try and dilute mixture but will no real difference.

Oh and also when I tilt the motor forward a lot of fuel comes running out of the carbs into the intake plenum and proceeeds to leak into the cowling and down the motor, I don't see a real good way to stop that but my ignorance might be blinding me to a solution.

this motor is really only a stop gap till I can get my bubble back 140 from the machine shop and rebuild it so a hack repair is not below me on this old pig.

Thanks for any info
 
I should say it runs like stink after it idles for a minute or two in the water, I have to play with the high idle to get it to wake up and will usually be a big old cloud of smoke after I do that
 
Hopefully someone will jump in here to state, for sure, what the full spark advance is for a 1977 175hp Evinrude.

Carb throttle linkage between carburetors:
1 - Loosen roller set screw and back the roller away from the cam so it's not touching anything.
2 - Adjust the throttle linkages between carburetors so that they close at the same time and open at the same time.
3 - Now, adjust the roller so that the throttle butterflies just start to open when the scribe mark of the metal cam is dead center with the roller. Tighten the roller set screw.

If you tinkered and changed the adjustment of the horizontal threaded rod that goes between the vertical throttle arm and the metal cam... you'll need to reset the idle timing to whatever it's supposed to be.

Use Champion QL77JC4 spark plugs gaped at .040 .

A tilted engine will have fuel dripping out of its carburetors... BUT... perhaps you carbs need the float levels looked at. If you're using portable tanks that can be pressurized by the sun, loosen the fuel cap to relieve the pressure on the carburetors when tilted.

Let us know how the above works out for you.... precisely, in detail.
 
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