9.9 won't start - Troubleshooting tips?

[crguy]

Motor - 2000 Merc. 9.9. won't start. I have spark, tryed fresh gas. Will run by spraying starter fluid into carb throat. Fuel filter/bowl is clean. I seem to have a back pressure when I disconnect the fuel line from the motor. It appears to be clearly a fuel problem. I don't have a lot of experience working on outboard motors, but I am mechanically inclined and was hoping to fix this myself.<br /> Can anyone give me a troubleshooting sequence? Also where is the fuel pump on this motor? Thanks for any help

 

[jim dozier]

Re: 9.9 won't start - Troubleshooting tips?

It may help for you to peruse the FAQ section of this forum. You are right you have a fuel delivery problem. What exactly did you mean by backpressure when disconnecting the fuel line? Basically you have 3 fuel areas to investigate. <br /><br />1. The gas tank and associcated fuel line and bulb to the engine.<br />2. The fuel pump and any filters in the engine.<br />3. The carburetor with the float valves, main and idle jets.<br /><br />Check each 1 separately. <br /><br />Can you tell if gas is getting to the carb when you pump the bulb. Try pulling off the fuel line and pumping the bulb. If gas is coming out of the line but not going in the carb your float valve in the carb may be stuck shut. Rebuild the carb.

 

[crguy]

Re: 9.9 won't start - Troubleshooting tips?

By back pressure I mean that when I take off the fuel line from the engine it sprays all over. I am going to remove the fuel line at the carb tonite to check the fuel flow. I know that I have fuel into the filter bowl when I squeeze the primer bulb. Therefore I assume that the check valve on the fuel connect if working ok. Where is the fuel pump on this motor and how can I confirm that it is working. Is there a screen or filter before it that could possibly be clogged?<br /><br /><br />Thanks for your input

 

[jim dozier]

Re: 9.9 won't start - Troubleshooting tips?

The fuel pump is usually a round puck-like device bolted to the engine with a fuel line running to the carb. Follow the fuel line from the carb back to it. I believe from your description, that your carbs are in need of a thorough cleaning/rebuild. Either the float valve in the carb bowl is stuck closed (not letting gas in the carb bowls) or if as I think you said, gas is getting in the carbs, then the main metering jets are clogged with crud and need cleaning. Either way remove the carbs, buy a rebuild kit (usually a new float valve and some gaskets), dissassemble the carbs completely and clean ALL orifices and jets with spray carb cleaner AND compressed air. Install the rebuild kit, set the float height and idle mixture screw (which you removed in the cleaning process) to manual specs and reinstall.

 

[BassMan31]

Re: 9.9 won't start - Troubleshooting tips?

Has the motor ran this year?? Also is this fresh gas?? Your fuel may have left varnish in your jets over the winter.

 

[crguy]

Re: 9.9 won't start - Troubleshooting tips?

The motor ran fine earlier this year. I ran the tank almost dry and I do think that I sucked up some crud into the carbs. Also, jimd thought that the carb bowl is stuck closed thus not letting gas into the carb seems to fit the problems and symptoms I am having. I will have to take off the carb and rebuild.