OK... A few things to consider here. First, that stupid air box and gasket must be installed properly or the engine will run lean at high RPM and stall out. But, in this case the engine kind of sounds rich. Now, that damn "primer" could be an issue. It has three positions: Off/warm up/prime.... Here is a case where OMC spent more money and made things much worse... When you pull that primer all the way out, it actually pumps extra fuel into the carb through that top hose (provided you have built up pressure in the fuel line with the fuel tank primer bulb). The warm up position just allows a little extra fuel to bypass the primer and help the engine warm up through that hose on top of the carb. And OFF doesn't allow any extra fuel into the upper carb hose. One of the big mistakes many owners make is pulling the primer all the way out, starting the engine, then forgetting to push it all the way back in after it warms up a bit. So, to rule out flooding/primer malfunction, simply pull the hose off the top of the carb while the engine is misbehaving to see if it clears up. Like I said, kind of sounds rich at high speed also. So, once the primer has been ruled out then we have to revisit that GD horrible plastic carb. You replaced that little rubber hose (idle circuit pick up) which is a common issue. But I am thinking you may have forgotten to reinstall that brown colored gasket under the white fuel pick up that sits at the bottom of the bowl. Think of the old style OMC carbs and that thick donut gasket that sits between the bowl nozzle well and carb body... Leave that out and it will probably run rich at high RPM because fuel is short circuiting into the main nozzle/bypassing the high speed needle. That brown rubber gasket on this newer carb serves the same purpose as that old cork donut gasket. Now onto the crazy sync process on this engine. Gone are the days of the throttle valve being completely closed at idle...See that screw/spring above the metal throttle arm on the carb?? That is the throttle cracking screw. I forgot what the initial setting is, but the throttle valve on these carbs is actually held slightly open at idle. There is no hash mark on the throttle cam because it is suppose to be set so the cam starts pushing the carb open immediately when the throttle is advanced. There is actually an idle timing setting on these engines, see the little moveable idle timing stop on the left side of the powerhead? I'm guessing you did not mess with that so probably do not have to worry about that setting. I have forgotten just what the initial idle mixture adjustment is as well. But, it probably from what the manual says because it looks like that plastic top on the carb has been replaced. The actual syncronization process for this engine is quite "involved", way too complicated for sure. Finally, you reported that that cheesy adjustable plastic cam was broken and you cemented it back together. Are you sure the carb is opening up properly at WOT?
@@donk499 Wow! I read that about three times. Thank you for the help, I will dig into it tomorrow. I’m thinking that bottom gasket isn’t in place. The thick donut one in the middle that the main jet screws into is in place though. It is fun for me to learn these things. I appreciate the thoughtful words!!!
@@OutboardMotorFun "thick donut one around the main jet..."?? Glad to help, hope it works out... Those carburetors are awful, and the sync procedure is way too complicated!
Good thing you had that old Johnson to get you back to the dock.
Thank God for that one!! 😆
OK... A few things to consider here. First, that stupid air box and gasket must be installed properly or the engine will run lean at high RPM and stall out. But, in this case the engine kind of sounds rich. Now, that damn "primer" could be an issue. It has three positions: Off/warm up/prime.... Here is a case where OMC spent more money and made things much worse... When you pull that primer all the way out, it actually pumps extra fuel into the carb through that top hose (provided you have built up pressure in the fuel line with the fuel tank primer bulb). The warm up position just allows a little extra fuel to bypass the primer and help the engine warm up through that hose on top of the carb. And OFF doesn't allow any extra fuel into the upper carb hose. One of the big mistakes many owners make is pulling the primer all the way out, starting the engine, then forgetting to push it all the way back in after it warms up a bit.
So, to rule out flooding/primer malfunction, simply pull the hose off the top of the carb while the engine is misbehaving to see if it clears up.
Like I said, kind of sounds rich at high speed also. So, once the primer has been ruled out then we have to revisit that GD horrible plastic carb. You replaced that little rubber hose (idle circuit pick up) which is a common issue. But I am thinking you may have forgotten to reinstall that brown colored gasket under the white fuel pick up that sits at the bottom of the bowl. Think of the old style OMC carbs and that thick donut gasket that sits between the bowl nozzle well and carb body... Leave that out and it will probably run rich at high RPM because fuel is short circuiting into the main nozzle/bypassing the high speed needle. That brown rubber gasket on this newer carb serves the same purpose as that old cork donut gasket.
Now onto the crazy sync process on this engine. Gone are the days of the throttle valve being completely closed at idle...See that screw/spring above the metal throttle arm on the carb?? That is the throttle cracking screw. I forgot what the initial setting is, but the throttle valve on these carbs is actually held slightly open at idle. There is no hash mark on the throttle cam because it is suppose to be set so the cam starts pushing the carb open immediately when the throttle is advanced. There is actually an idle timing setting on these engines, see the little moveable idle timing stop on the left side of the powerhead? I'm guessing you did not mess with that so probably do not have to worry about that setting. I have forgotten just what the initial idle mixture adjustment is as well. But, it probably from what the manual says because it looks like that plastic top on the carb has been replaced. The actual syncronization process for this engine is quite "involved", way too complicated for sure.
Finally, you reported that that cheesy adjustable plastic cam was broken and you cemented it back together. Are you sure the carb is opening up properly at WOT?
@@donk499 Wow! I read that about three times. Thank you for the help, I will dig into it tomorrow. I’m thinking that bottom gasket isn’t in place. The thick donut one in the middle that the main jet screws into is in place though. It is fun for me to learn these things. I appreciate the thoughtful words!!!
@@OutboardMotorFun "thick donut one around the main jet..."?? Glad to help, hope it works out... Those carburetors are awful, and the sync procedure is way too complicated!
You were 100% correct. The seal on the bottom was bad. Seems to work perfect after a carb rebuild kit. I will water test soon
@@OutboardMotorFun Cool, so happy it worked out