1957 evinrude Big twin 35

[eolsen]

Where the lower unit bolts to the mid section I am getting exhaust bubbles there. It appears from a few of the bolts. Should this be happening and could this affect the compression in the engine? I have rebuilt everything from the top secret files on reviving an old motor. I can get the starter to rotate the flywheel put in in gear but when I cut the power to the starter it stops.

 

[HighTrim]

From the bolts? Sorry not understanding.

So the motor will not start? Has it ever ran for you?

What is compression? Spark jump 1/4" gap on an inline tester? Spraying pre mixed fuel into cylinder get it to fire for a second?

 

[F_R]

I am assuming you are saying it leaks where the lower unit bolts onto the exhaust housing. The answer is it is perfectly normal and does not affect compression or running in any way at all. There is exhaust inside there and no kind of gasket or anything to prevent it escaping. Anything that does get out there was destined to go out the underwater exhaust outlet anyway

 

[eolsen]

Yes, and thanks FR. High Trim, I have 90 in each for compression with the pull start. I have tried spraying WD and oil gas mix with and occasional backfire sound and that's about all I get. I rebuilt magneto(coils, points, condensers), I have spark that jumps almost 1/4". I rebuilt carb. The starter engages flywheel beautifully but the minute I cut power to starter the motor stops. ( I'm giving the starter power directly from a battery) for testing purposes. I have not gotten it running. It seems like it's running when the starter is turning the flywheel. Could it be maybe it's only running on one cylinder? I'm at a loss.

 

[HighTrim]

What are your needles set at? What plugs are you using? Flywheel key not sheared? Did you torque flywheel nut?

 

[eolsen]

I followed the top secret file carb settings. Flywheel key is not sheared. Nut is torqued to 65.

 

[eolsen]

Oh and Champion j6c plugs

 

[HighTrim]

I wonder if your cut out switch is shorted? Has anyone added any kill switches to it? Is it running on fuel pump, or original pressure tank?

 

[eolsen]

Yeah it has a kill switch with the two black wires that lead to the magneto. The kill switch is an old momentary push button. I got rid of pressurized tank and installed a fuel pump.

 

[HighTrim]

Disconnect kill switch and try. DIsconnect cut out switch on side of block and try. WHich cylinder is the pump run off ofÉ

 

[eolsen]

Top cylinder bypass cover. And thanks for all the info you're giving me. You are giving me ideas I haven't tried yet.

 

[eolsen]

Well I tried disconnecting kill switch and cut out switch............ no change.......
Heres what im doing. I am jump starting the starter directly from a battery. It engages the flywheel and the motor sounds like its running, with exhaust coming out. I can place it into gear forward and reverse and it gets the water kickin' in the barrel. But the starter never disengages from the flywheel. Then when I cut the power from the starter, the motor stops.
Maybe i should try to post a video?

 

[tomhath]

When you checked the spark did you use the starter motor to spin it or the rope? If you have spark using the rope I'd check the timing, it might be way off.

 

[eolsen]

By checking the timing I'm guessing you mean setting the points?

 

[F_R]

Sounds like it is just basically sick. Like low compression, but you say that's ok. Possibly crankcase compression. Trash, critters, whatever, in the reeds?? Maybe something to do with the abandoned tank pressurizing valves. Maybe reed plate gaskets?? Badly scored piston skirts?

That 90psi with the pull starter---was that with the compression relief disabled?

OK, I admit, just some educated guesses.

 

[eolsen]

No, compression was with it enabled

 

[F_R]

Ok, that explains why it is low (normal under the circumstances)

 

[eolsen]

If it were something in the reeds. Would I notice it upon removing the cover on the carb side? Or could it be debris on the piston side? I actually checked it a day ago and they look spotless on the carb side but I didn't fully remove....I don't wanna give up on this baby but my patience is wearing thin.

 

[singer202]

I know this may sound crazy, but I just rebuilt an engine almost identical to this and had a similar issue. Turns out my brand new Champion plugs were either defective or don't play nice with these motors. Its a silly thing, but try getting some new plugs of a different brand (I got NGK and they worked great) and see what happens.

 

[eolsen]

Thanks singer. I'll try that too