8 Mariner doesn't start... did yesterday

[AGENT 37]

I have a Mariner 8hp, S/N: OD214786, I'm not sure of the year. It was running great three days ago but will no longer start. I checked the kill switches with a multimeter and they are working properly. I pulled the plugs, grounded, and checked for spark. It is present. With plugs pulled I looked into the cylinders and saw fuel mist when pulling start. I attempted to both mist raw fuel into the carb and even tried a little shot of starter fluid into the cyliders and it would not fire. I made a slight adjustment on the fuel control the other day when it was still running because it was flooding out at idle after high rpm. I got it to run perfect. The outboard is pristine and is usually a two-puller. Any tips?

 

[jimlad]

Re: 8 Mariner doesn't start... did yesterday

maybe carb problem when was it last overhauled

 

[Laddies]

Re: 8 Mariner doesn't start... did yesterday

The kill switch in the handle cause problems like that unplug it and ck for spark

 

[AGENT 37]

Re: 8 Mariner doesn't start... did yesterday

I already have spark when both of the kill switches are hooked up and the clip switch is in the run position. I Checked both switches with a multimeter at the quick connect (where they come together into an environmental splice); in the run position I have no continuity to ground, in the stop position I have continuity to ground.... both switches. Any idea what reading I should get on the other side..... I have a ground but I assume that is normal ops going into the solid state.

As far as the carb, I didn't have to overhaul it. I simply adjusted the brass srew running into the top of the carb (needle) to adjust the fuel mix. The motor was running when I did this and started after I did this.

Do you folks know what year this motor might be. I'm guessing by apperance to be around 95, if not newer.

 

[AGENT 37]

Re: 8 Mariner doesn't start... did yesterday

I don't have a book yet, that's why I'm asking for electrical help, otherwise I'd just look at the wiring diagram. Thanks.

 

[jimlad]

Re: 8 Mariner doesn't start... did yesterday

disconnect kill switch and try and start it if not it maybe switchbox

 

[Plainsman]

Re: 8 Mariner doesn't start... did yesterday

0D182000 - 0D280999

1993

Also don't use starting fluid or raw gas to start. Use a premix.

If your seeing fuel in the cylinder, then I would think it was a spark issue. I know you said you have spark, but is it a good blue spark and how did you test it?

 

[emckelvy]

Re: 8 Mariner doesn't start... did yesterday

If it wouldn't fire even with starter fluid I'd say you're running too rich (that is if you are absolutely sure there's good spark).

Perhaps fuel pump problem or carb problem. If your carb has a primer valve vs. choke butterfly, and that primer ckt is stuck open, it'll flood the engine. Or maybe a leaking carb float needle/seat.

A leaking fuel pump diaphragm would be another thing to look for.

On the spark thing, if you have a timing light you can clip the pickup around each spark plug lead and check for firing indication with the plug installed in the cylinder. This way you'll know for sure you're getting spark under pressure.

Or a cheap neon firing indicator, commonly available at auto parts stores.

You can make your own spark testing tool by clipping the ground electrode off an old spark plug; if the spark jumps the resultant gap, it should be of adequate strength to fire under compression. You'll find this type of spark tester at many auto parts stores, too.

Here's a few typical examples:

http://www.thetoolwarehouse.net/shop/TTW409.html

http://www.nextag.com/spark-tester/search-html

HTH & keep us posted..........ed