97 merc 200 efi stalling at cruising speed,,,

I was cruising the other day at Butla around 3500 rpm and all of a sudden my motor totally quit..... I turned the key back on waited a few seconds and she started up immediately with no problem,,,,, Went back to crusing speed again for awhile when all of a sudden, My teeth once again almost stuck into the front glass,,,,, I checked the fuel lines and everything looked okay, boat restarts just fine and runs fine as long as I don't take her over 3000 rpm unless I want it to stall,,,,I check the internet and seems a lot of guys with the mecurys have had this issue before and said it was this or that , but the only guys who said it totally fixed his issue was someone who said that he changed his fuel lines that were grey in color because mercury has had issues with fuel breaking down the fuel line from the inside out and it leaves grey chunks in your dryer , filter and needs to be changed,,, anyone have similar issues with any of their mercury engines? I I need to get this issue fixed fast,,,,, thanks takeum

First thing I would do is look for a filter separator on the motor itself. If it has one check it to see if it has those gray or black particles in it. It could be a fuel problem but sounds more like an electrical problem or it could be your high pressure fuel pump since it is an injected motor. Might go over to Bassboatcentral. Check their mercury board and may have some info there. Seems I read something similar over there a few months ago.

If your motor has the square fuel pump, and I think it does, this could be The one of the very few confirmed ethanol problems. Ref: Mercury Service Advisory No. 2001-17. The symptoms are as follows: you are cruising along at WOT all of a sudden it is like someone turned the motor off. The motor will start right back up but will continue to do this unless you throttle way back. The problem is caused by the check valves in the fuel pump and the fix is to rebuild the fuel pump. You must get the Mercury kit as it contains new style check valves. What happens is over time ethanol causes the edges of the check valves to curl up slightly and they no longer seal properly. The newly styled check valves do not have any rubber on them and are just round pieces of plastic type material.

Well,mm I know it doesn't have the square fuel pump seeing I I pulled it apart just last fall to clean the entire mixing container and float and needle valve.... I am hoping to check the fuel separator tomorrow for debris. It sounds like mercury has had several issues with this very same problem,,,

OK, I was guessing this was the one http://www.boats.net/parts/search/Me...TER/parts.html

I thought you meant electric
fuel pump that pulls fuel out of the tank in the VST,,,,, yes,mm I do have that type fuel pump your talking about,mm perhaps have that checked out,,,, thanks Bill,,,

Inspect the square pump, it will have gasket material hanging out the sides. If that material is coated with paint, rebuild it. The old check valves will be stiff and unable to function properly. If you have the gray fuel lines, replace them with a quality ethanol rated fuel line of 3/8ths I.D. The trouble you are experiencing can be caused by the fuel and ignition system. If the motor is starving out of fuel at 3k rpm, it's got big fuel delivery problems. If the fuel system updates do not cure the problem, it would be wise to seek the help of someone familiar with that ignition system. I believe the 97 model has the CDM ignition and can be aggravating to diagnose.

(As a foot note, you have what's known as an 'anti siphon valve' that is located at the point where the fuel line leaves the fuel tank. I have seen a hand full of cases where the valve stuck in a highly restrictive position. It may be a good idea to check that after updating the system components. A weak pump may not provide adequate low pressure to unseat an otherwise good valve. The complaint in the cases of the stuck valve were the same as yours.)

I replaced with ethanol rated automotive fuel line,,, will that work ya think or will it be too soft? I also need to figure out what a drill bit .125 equates to fractions which my drill but assortments have,,,

.125 is 1/8th inch. The automotive fuel line is preferred

Thanks for the help guys,,,, I finally figurd it out after awhile of rebuilding fuel pumps and checking fuel lines,,,, I found a collaspsed fuel line running from the VST to the fuel filter on opposite side of engine,,,, replaced with of those lines coming off fuel filter to VST and fuel pump and found that one of them was almost completely closed,,,, I Coukd hardly blow through one of those hoses,,, So after 16 years of running ethanol fuel based fuels it finally ruined my fuel lines,,,, So a total fuel line replacement has been planned,,,, everything on motor has been taken care of,,, Niw I just need to figure how to replace my Rangers fuel tank hoses to engine,,,At least she's up and running like she used to ....