O.S. outboard won't start

[Chris Dixon]

My friend has an O.S water cooled outboard that was bought as new....still has a real tight spot in the sleeve. So it feels new and after inspection inside the muffler chamber it appears new to me. Anyway it will not start at all. I've been messing with O.S outboard for about 3 yrs now and this one has me stumped...The glow plug is good. The fuel is good and the only way it will even make and effort to fire is if we put a little fuel in the carb or cylinder then it will run for a couple seconds. Needle valve is has been turned form 2 to 2.5 out and nothing. The mixture control screw appears to be set correctly. Any suggestions?

 

[Ben Ballard]

I am by no means a expert, but it sounds like a fuel delivery issue. I would check that there is no blockage from the pressure nipple to the tank or a air leak at the tank. Then I would check that a pice of crud has not gotten to the needle... Try squirting wd-40 through the fuel inlet to the carb at wot. I would try this with carb off the engine as I have heard that wd is not goodon some of the smaller engines with a crank insert... Not sure if yours has one or not. Hope this helps.... I'm sure someone with more experience will chime in.

 

[Duck899]

First thing to do is remove pressure line and fuel pickup line and pressure the tank to check for air leaks. Put a piece of fuel line on the carb nipple and with the carb fully open blow through it. If you have a flow meter it should flow around 70. Make sure all the bolts are tight on the engine. Open the needle valve and start the engine with finger over the carb opening. The engine should pull fuel up the fuel line if the carb is partially closed and then start.

 

[Chris Dixon]

With the fuel line off the motor it spews fuel while spinning the motor with the starter....I checked mine and it does not do this and it still starts instanly....go figure..lol

 

[Chris Dixon]

First thing to do is remove pressure line and fuel pickup line and pressure the tank to check for air leaks. Put a piece of fuel line on the carb nipple and with the carb fully open blow through it. If you have a flow meter it should flow around 70. Make sure all the bolts are tight on the engine. Open the needle valve and start the engine with finger over the carb opening. The engine should pull fuel up the fuel line if the carb is partially closed and then start.

If it is spewing fuel out of the line while spinning the motor wouldn't that eliminate the fuel pressure issue? I always put my thumb over the carb on a cold motor and sometimes when needed on a warm motor. He has new fuel lines with a tee inline/plug for a filler tube. The fuel line is a little longer than normal but it should atleast hit a note right?

 

[Wayne Johnstone]

Is they glow plug ignitor working?

 

[Chris Dixon]

Is they glow plug ignitor working?

Yes I can take the same glow starter to my boat and it starts fine....can take the glow pug out and check it and it glows bright...I also have a glow starter lead on my power panel that shows it working in the green ( about 3 amps)...even tried a few different glow plugs and still no luck.

 

[Ben Ballard]

Well, that will tell you that you are getting fuel to the carb, but what is happening then? As duck said, blow through your needle and see that it is clear... Sounding more like junk in the needle to me. Might take the needle completely out when you blow through it to make sure its clear. I am not a big fan of nitro on my lips that's why I suggested the wd but either way you need to make sure the fuel is getting through the carb to the engine.

 

[Robert Pickard]

are you starting it in the right direction remember O/Bs start up opposite of I/B

 

[Chris Dixon]

are you starting it in the right direction remember O/Bs start up opposite of I/B

yes..lol

 

[HTV Boats]

The fact that the motor runs by manually injecting fuel points to the problem. Either tank & lines or carb. Try a new or known good fuel tank & lines first then take both high and low speed needles out of the carb an look for any blockages. Blow everything out and reassemble. All the OS's I have run around two turns out on the main needle. If your low speed screw on the other side is turned in too far it can all but block fuel. Back it out till the O-ring barely shows. This should take out of play. If you can get it too run and get the high speed set correctly then run at slow speed and accelerate turning the low speed in a little at a time till acceleration response is crisp.

Mic

 

[Chris Dixon]

The fact that the motor runs by manually injecting fuel points to the problem. Either tank & lines or carb. Try a new or known good fuel tank & lines first then take both high and low speed needles out of the carb an look for any blockages. Blow everything out and reassemble. All the OS's I have run around two turns out on the main needle. If your low speed screw on the other side is turned in too far it can all but block fuel. Back it out till the O-ring barely shows. This should take out of play. If you can get it too run and get the high speed set correctly then run at slow speed and accelerate turning the low speed in a little at a time till acceleration response is crisp.

Mic

Thanks Mic...I think he got it narrowed down to the low speed screw turning itself in because the when he would give it throttle it would somehow turn the low speed screw in....something was bent in the carb?