6HP Johnson

kiwiguy

Seaman
Joined
Jun 8, 2002
Messages
72
I have an 81 6hp which starts first time cold.<br />As soon as it warms up it is VERY hard to start.<br />What should I be looking at?
 

Xcusme

Commander
Joined
Apr 21, 2003
Messages
2,888
Re: 6HP Johnson

......girls, at the beach....just kidding....<br /><br />Something isn't right if you're having problems starting a warm motor. <br />A few things to consider....<br />Is the cooling system working OK?? Is it overheating??<br />What are the compression figures? Cold and warm.....<br />Last time carb was overhauled?? Float sticking-flooding motor?<br />Fuel lines OK?? No vacuum leaks.<br />Fuel pump operating OK??<br />What do the plugs look like after it warms up?? Wet? Black?<br />What re-starting procedure are you using when you try to restart motor??<br />Tank properly vented??<br />Spark the same, cold and warm??
 

kiwiguy

Seaman
Joined
Jun 8, 2002
Messages
72
Re: 6HP Johnson

Thanks for the reply X.<br />Firstly I like your sense of humour.<br />Carb has just been re-built. compression is around 120 in both cylinders. Plugs seem to be a tad wet fouled and are running 50:1 Tank vent is open, New fuel line and bulb, seems to start warm on half choke !!!!!!!<br />And by the way, living in Surfers Paradise there ain't much else a bloke can do but watch the bikini clad talent....
 

kiwiguy

Seaman
Joined
Jun 8, 2002
Messages
72
Re: 6HP Johnson

Sorry, forgot to add that when you pull the fuel connector off the engine it leaks.... should this happen?
 

Xcusme

Commander
Joined
Apr 21, 2003
Messages
2,888
Re: 6HP Johnson

If memory serves, there's no check ball on the motor fuel line connector, just the fuel line input and it's locking pin. If a few drops of fuel do leak from this connector, it's just the fuel in the hose going to the input of the fuel filter. If the fuel line from the tank is leaking when you disconnect it from the motor, then there is a problem. Replacement O-rings are available to reseal those connectors. Fuel leaks, loss of fuel line vacuume, air intrusion , can result from leaking connectors. Since your fuel lines and primer bulb are new, you shouldn't have any concerns. Since you have to half-choke it to start, this might point to a clogged low speed idle jet or perhaps your running it a bit lean at idle. <br /><br />Thanks to our good friend Joe Reeves, here at iboats, I offer the following::<br /><br />Depending on which carb you have, pick one of the following.<br /><br />(Carburetor Adjustment - Single S/S Adjustable Needle Valve)<br /><br />Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.<br /><br />Start engine and set the rpms to where it just stays running. In segments of 1/8<br />turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to<br />respond. As you turn the valve in, the rpms will increase. Lower the rpms again to<br />where the engine will just stay running.<br /><br />Eventually you'll hit the point where the engine wants to die out or it will spit back<br />(sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4<br />turn, you'll find the smoothest slow speed setting.<br /><br />When you have finished the above adjustment, you will have no reason to move<br />them again unless the carburetor fouls/gums up from sitting, in which case you<br />would be required to remove, clean, and rebuild the carburetor anyway.<br />--------------------------------------------------<br />(Carburetor Adjustments - Two Adjustable N/Vs)<br /><br />Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow<br />speed = seat gently, then open 1-1/2 turns.<br /><br />Setting the high and low needle valves properly:<br /><br />NOTE: For engines that DO NOT have a shift selection, obviously there is no<br />NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low<br />speed needle valve adjustment.<br /><br />(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to<br />full throttle. In segments of 1/8 turn, waiting for the engine to respond between turns,<br />start turning in the bottom high speed needle valve. You'll reach a point whereas the<br />engine will either start to die out or spit back (sounds like a mild backfire). At that<br />point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the<br />smoothest setting.<br /><br />(Low Speed) Slow the engine down to where it just stays running. Shift into neutral.<br />Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few<br />seconds for the engine to respond. As you turn the valve in, the rpms will increase.<br />Lower the rpms again to where the engine will just stay running. Eventually you'll hit<br />the point where the engine wants to die out or it will spit back. Again, at that point,<br />back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed<br />setting.<br /><br />When you have finished the above adjustments, you will have no reason to move<br />them again unless the carburetor fouls/gums up from sitting, in which case you<br />would be required to remove, clean, and rebuild the carburetor anyway.<br /><br />--------------------<br />Joe (30+ Years With OMC)
 
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