7.5 Merc won't run on its own.

[LOATS]

First, hello, I'm LOATS, director of Michigan Land Rescue Team, a group of volunteers who dedicate their time cleaning Michigan's public sporting areas.

I know I'm not supposed to use starter fluid, but I did try it and the motor will start. However, when trying to start on its own, there is no fuel getting to the cylinders. I pumped the ball, its solid. I think it may be an issue in the carb. Is this something I can take apart and get back together, taking into consideration I've never done it before and never have seen it done.

Thanks----Ben

 

[lindy46]

Re: 7.5 Merc won't run on its own.

Get the motor started by spraying premix into the carb. Then pump the ball. If it will continue to run if you pump the ball, but dies when you quit pumping, it's a bad fuel pump.

 

[RLT III]

Re: 7.5 Merc won't run on its own.

when I first got my boat/motor it would not crank and we did the starting fluid to make sure it fired but only a second ended up I took the carbs off and the chokes (2carb) where gummed shut and would not allow fuel in so i took them off cleaned them with carb cleaner/injector and it fired up ran good and then the fuel pump went so replaced that and all is good Hope that helps

 

[LOATS]

Re: 7.5 Merc won't run on its own.

I appreciate the help. I took the carb off cleaned the diaphram and strainer, but I could not see how to easily get the float off. Is there an orafice of some sort in which taking the float off would allow it to be cleaned?

 

[CharlieB]

Re: 7.5 Merc won't run on its own.

Have the model and serial # of your motor handy, then go here to look up the exploded parts diagrams

http://www.mercruiserparts.com/SelectModelType3.asp?class_id=2

Go here to find an on-line service manual and follow the directions spelled out to clean and adjust the carb.

http://web.ebscohost.com/serrc/sear...1d93-17e8-466a-ae3d-14cf9280de42@sessionmgr10

 

[LOATS]

Re: 7.5 Merc won't run on its own.

Great websites, thank you. One little issue, there is no manual on the latter website for my motor, 1980-83 7.5 Merc.

The first website does give me a nice blow up.

After further review, I am determined the inlet valve to the bowl is clogged. With the debris that was in the bowl, I am convinced there is some in the inlet valve. From looking at it, I believe I am going to have to take off the float. I am going to spend some time here soon and take the carb apart again and work on that inlet valve. Thanks, again.

 

[LOATS]

Re: 7.5 Merc won't run on its own.

I have the float off, any have any idea on how to remove the inlet needle to clean it?

 

[pointandshoot]

Re: 7.5 Merc won't run on its own.

if you have the float off the valve should fall out when you turn the carb upside down. if it doesn't then thats probably your problem because no fuel is getting to the carb. was the float bowl full of fuel when you took it off? may have to use a little bit of muscle to get the valve out if its stuck, and you might want to replace it if it looks nasty.

 

[LOATS]

Re: 7.5 Merc won't run on its own.

That is what happened. Blew it out withsome starter fluid, put it back together, bam, works great. Thanks!