72 Evinrude 50hp Lark, 50273c
I've been working on the damned engine for years and it just refuses to run right (or maybe I refuse to fix it right, anyway..). The previous signs were low power output, poor fuel economy, and intermittent hard starting.
Recently I discovered a crack in the fuel line that was effecting the vacuum. While repairing it, I decided to service the carbs and reed valves, and install new gaskets.
After the work was all done the engine wouldn't start. I managed to get it to crank on by opening the throttle and cranking repeatedly. After that, she seemed to run well, but today when I tried starting it up I couldn't get a pop out of her.
The engine has:
New spark plugs/caps
New head gasket (125 psi on both cyl.)
New power pack- spark is fine
Solid, tested wiring
New fuel pump
No evident leaks from p' head flange
Good fuel & bulb that pumps to rock hard (good vacuum)
Sparkling clean carbs and all new gaskets
Floats adjusted to manual specs- no lower than 1 5/8, no higher than 1 1/8'', from flange to float bottom (I basically set them both in the middle of these figures).. maybe I managed to set them wrong somehow.
Reed valves seem fine. When I removed them a few of the reed petals had bent up a bit so, by lightly tugging them down repeatedly, I managed to get them back flush with the block.
The carbs don't have mixture needles, so that's out of the equation.
.. I just don't get it!
One thing I did notice yesterday was fuel leaking down the inside of the exhaust cover, out at the lower unit vents. I chalked it up to flooding, but could it be an indication of something else?
Also, I removed the spark plugs today and gave it a few cranks with my hand over the plug holes. What I got was white-ish vapor, which I ***ume is correct; it didn't get my hand wet, but appeared to be vapor. However, the 'puffs' coming from cyl. 1 were noticeably stronger/more forceful than from cyl. 2. This doesn't seem good.
ANY ideas???
Thanks for bearing with me, I know this was a long one.
I've been working on the damned engine for years and it just refuses to run right (or maybe I refuse to fix it right, anyway..). The previous signs were low power output, poor fuel economy, and intermittent hard starting.
Recently I discovered a crack in the fuel line that was effecting the vacuum. While repairing it, I decided to service the carbs and reed valves, and install new gaskets.
After the work was all done the engine wouldn't start. I managed to get it to crank on by opening the throttle and cranking repeatedly. After that, she seemed to run well, but today when I tried starting it up I couldn't get a pop out of her.
The engine has:
New spark plugs/caps
New head gasket (125 psi on both cyl.)
New power pack- spark is fine
Solid, tested wiring
New fuel pump
No evident leaks from p' head flange
Good fuel & bulb that pumps to rock hard (good vacuum)
Sparkling clean carbs and all new gaskets
Floats adjusted to manual specs- no lower than 1 5/8, no higher than 1 1/8'', from flange to float bottom (I basically set them both in the middle of these figures).. maybe I managed to set them wrong somehow.
Reed valves seem fine. When I removed them a few of the reed petals had bent up a bit so, by lightly tugging them down repeatedly, I managed to get them back flush with the block.
The carbs don't have mixture needles, so that's out of the equation.
.. I just don't get it!
One thing I did notice yesterday was fuel leaking down the inside of the exhaust cover, out at the lower unit vents. I chalked it up to flooding, but could it be an indication of something else?
Also, I removed the spark plugs today and gave it a few cranks with my hand over the plug holes. What I got was white-ish vapor, which I ***ume is correct; it didn't get my hand wet, but appeared to be vapor. However, the 'puffs' coming from cyl. 1 were noticeably stronger/more forceful than from cyl. 2. This doesn't seem good.
ANY ideas???
Thanks for bearing with me, I know this was a long one.
Comment