'92 40 hp Johnson, full throttle dies

[DrinkingEmu]

'92 2 stroke oil injected 40 hp attached to 17 ft tracker tx17.<br /> -Idle is fine<br /> -throttle in N is fine, rpm revs no prob<br /> -in gear 1/2 throttle is fine<br /> -in gear from 1/2 to full throttle engine stumbles,and hesitates,and feels like it is trying to go. When the throttle lever is pushed all the way the engine starts to die, until you back the trottle off, back to the 1/2 point. At this point the engine comes back.<br />Ideas of where I should start to look ?????

 

[BoatBuoy]

Re: '92 40 hp Johnson, full throttle dies

Water in the float bowl would be my guess. Needs carb clean & carb kit.

 

[OBJ]

Re: '92 40 hp Johnson, full throttle dies

Just made a repair on just such an engine last week....89' 40hp with the exact same problem.<br /><br />Now this may not be the case with yours....when I check the pump, I found the fuel diaphram was split and the quad ring seal between the motor housing and fuel housing was bad. The oil had long been disconnected from the pump so the owner opted for a standard fuel pump.<br /><br />An OEM service manual would show you how to check the pump.<br /><br />Again.....this may not be the case with yours.<br /><br />Check all other possibilities as BoatBuoy has suggested. A clear piece of tubing from the pumps fuel outlet to the fuel manifold can tell you if your getting air into the fuel supply to the carbs. You will see bubbles in the fuel flow.

 

[DrinkingEmu]

Re: '92 40 hp Johnson, full throttle dies

I put the clear hose on the pump outlet to the fuel manifold. <br />(Boat is now running with those ear muffs) <br />- don't really see any bubbles (how small would they be?)<br />- the clear hose makes a curved 90 deg turn to manifold, just like black hose did.<br />-used hose clamps so no air could leak in<br />-The clear hose does not stay full of gas at idle, is that normal?<br />-I ordered a Sieera fuel pump kit in case the pump does need service, but I am hesitant to pull that apart.

 

[DrinkingEmu]

Re: '92 40 hp Johnson, full throttle dies

Status update:<br /><br />-new plugs<br />-new gas<br />-carbs taken off, cleaned , new floats and seals<br />-new fuel filter<br />!!!Boat now jumps up onto plane on full throttle like a dream!!<br /><br />-new problem, when motor is at idle, and tilted all the way down for take off, it stalls. Partial throttle req'd for restart. Does this sound like an improper float adjustment ?

 

[tashasdaddy]

Re: '92 40 hp Johnson, full throttle dies

very possible, or too rich idle adjustment. thus flooding it.

 

[DrinkingEmu]

Re: '92 40 hp Johnson, full throttle dies

Hi thanks for help. Clean carbs make a world of differance. Boat runs realy nice<br />I have rechecked the float adjustment, holding the carb upside down the floats measures right and are parellel to body of the carb.<br /><br />What is process for idle adjusment? Is there a stardard number of turns? (I took the idle jets out when I cleand the carbs and didn't write down how much I turn them, and now the motor is hard to start)

 

[fireman57]

Re: '92 40 hp Johnson, full throttle dies

Do a search for carb adjustment at the top of the page. Joe Reeves has the best step by step on this procedure.