1985 70 HP Evinrude bogs down past 1/4 throttle

[jasonm96]

Heys guys,​

I recently bought a 16' runabout that has a 70 hp evinrude outboard on it. I did all the regular maintenance things to it after i got it (new water pump impeller, lower unit fliud, new plugs, etc) I started it for the first time on the hose and it idled great and went into gear no problem. took it out on the lake and starts up and idles fine, and at low speeds runs fine as well. But if i try to go past about 1/4 way on the throttle it bogs down and starts to die. I replaced the fuel line and bulb to rule that out and it still does it. I tried pushing in the choke when it started bogging down and it took right off and had no problems after holding the choke in for about 10 seconds. when i back off the throttle to slow back down it bogged down and died. I cleaned the carbs after that, they looked fine but soaked everything in carb cleaner, replaced the floats and float needle and seats. Took it out again today and found that the boat sounds like its idling slightly higher than it did before and it still bogs down when i throttle up past 1/4 way. Anyone have any suggestions? I know spark is good, and the engine has good compression.​

Thanks​

 

[tblshur]

:welcome:i dont know a lot i just wondered if you took jets out and cleaned them and pumped the bulb while it was acting up

 

[jakedaawg]

Well, if it runs better with the primer open then you need to revisit carbs. Dont just soak, you need to be able to squirt cleaner through each little orifice.

also verify that all the linkage is hooked up and butterflies open fully and at same time. Compression #'s should be posted.

take a fuel sample into a clear container. Even new fuel can be phase separated.

but, sounds like you missed something in the carbs or one of the fuel lines to the carbs is kinked or bad. Or stuck float or needle. Probably something silly.

 

[jasonm96]

Well, if it runs better with the primer open then you need to revisit carbs. Dont just soak, you need to be able to squirt cleaner through each little orifice.

also verify that all the linkage is hooked up and butterflies open fully and at same time. Compression #'s should be posted.

take a fuel sample into a clear container. Even new fuel can be phase separated.

but, sounds like you missed something in the carbs or one of the fuel lines to the carbs is kinked or bad. Or stuck float or needle. Probably something silly.

I sprayed cleaner through the nozzles, and blew them out with air. And as far as the compression number all 3 cylinders were between 130 and 135. I'll try taking the carbs apart and taking another look/ cleaning. I'll check the linkages, and take a fuel sample.

Thanks for the quick reply!

 

[jasonm96]

Well, if it runs better with the primer open then you need to revisit carbs. Dont just soak, you need to be able to squirt cleaner through each little orifice.

also verify that all the linkage is hooked up and butterflies open fully and at same time. Compression #'s should be posted.

take a fuel sample into a clear container. Even new fuel can be phase separated.

but, sounds like you missed something in the carbs or one of the fuel lines to the carbs is kinked or bad. Or stuck float or needle. Probably something silly.

Took apart the carbs again, found the high speed jet was plugged up, I must not have looked through that one after cleaning it the first time. Spraying carb cleaner through didn’t clear it out though. Compressed air did the trick though. Taking it out tomorrow to see how it runs, thanks for the suggestions!

 

[jakedaawg]

While not really best Practices, the tip cleaners for Oxy-Acetylene torch tips make great little pokers. You getthem at the local welding supplies store. Maybe 3 bucks for a little set.