Logo
FULL SITE MENU

1982 75hp Johnson bogs under load

M

mike77cj

Regular Contributor
"Carbs have been torn down, cleaned, ensured orfices are clear and reassembled with OLD gaskets.

When the boat is put in gear the engine bogs down. If I 'feather' the throttle slowly I can get up to half throttle.

With the boat tied securely to the dock I put it to half throttle and choked off the carbs with my hands. After five or so seconds the engine jumped to life and I am able to drop her to WOT.

Once back down to idle I need to manually choke out the carbs to get her going.

I verified that all the "nozzle gaskets" were replaced, but they are not new.

Could the old gaskets be allowing air to bleed through causing an over lean condition?

It is almost like the engine needs an inital vaccum to pull fuel up, but once flowing it is fine.

Hoping I am on the right path here, because running to the stern to choke out the engine then running back to the console is a bit dicey... haha.

Thanks!"
 
"make sure the rotating piece

"make sure the rotating piece under flywheel,..(timer base),..is moving freely,to its stop...if it is,..i'd say u need to put in NEW kits,as ur problem could be w/nozzle gaskets,..IF---everything is clean,and floats drop ok...new parts r cheap!"
 
"Timer base is moving freely.

"Timer base is moving freely.

Purchased new nozzle and bowl gaskets, broke down carbs, inspected them again and rebuilt with new gaskets.

I can now get the boat on plane SLOWLY, apply a bit of throttle at a time and get it to WOT without having to choke it.

It is definately a fuel issue..

--> primer bulb is hard
--> screen on fuel pump is clean
--> fuel lines from fump to carbs are NEW
--> plugs are new and gapped at .030

For kicks I am going to buy some Seafoam tonight and mix that in with fresh gas.

Again, once on plane and at WOT the engine sounds and runs great.

Thanks for the help!"
 
"Have someone with you pumping

"Have someone with you pumping the fuel primer bulb (acting as a manual fuel pump). If this cures your problem, you have either a fuel/air leak at some point between the pump and fuel supply OR a faulty fuel pump.

The electric choke has no effect? It should. There should be no need to choke it manually.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay store at:

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"
 
"I tried that (pumping bul

"I tried that (pumping bulb) this evening while a friend drove. No effect. The bulb remained hard.

The electric choke has an effect in helping the engine gain RPMs. My last post was just stating that I am now able to get to WOT w/o the assist of the electric choke.

Again, once the boat is on plane and the RPMs have spun to around 4000 or greater, she runs fine. It is just getting her there that is the problem...

Thanks for the help!"
 
Back
Top