Posted by jmlamia on 08/17/23 - 3:38 PM
#1
I purchased the boat in 2022, and used it a few times before the end of the season, with no issues. Launched in July 2023 and noticed the engine rough at about 1800 RPM. It is a 1999 Mercury 235 Carbed Optimax. Pro-actively I had the shop redo the fuel lines, filter and run the High Concentrate Cleaner on a small tank. Boat ran much better at all ranges after that. The next time out I ran about 1/4 mile and the engine shut down. Would not start. Pulled into marina and added 4 gallons of fuel which is all they had. Started right up and has been OK since. The Fuel gauge said I had 1/4 tank when it died. I now added about 23 gallons and I replaced the fuel sender and gauge. The gauge reads 1/2 tank now, but if I was empty and the tank is labeled as 61 gallons, I should be more like 1/3 tank, especially since I have been out 2 times since adding fuel. I checked the gas in the filter and it is clean, and I also tested the tank for any water and no traces. I used the goop that shows water as green. So now I am Leary of what the Fuel Gauge is telling me. I could not find any info about the original sender, but when I test it, it ranges from about 38 Ohms to 160 Ohms. The documents I read say it should read 33 to 240 ohms. When the boat died, the primer (which had just been installed) was deflated and remained that way. Once I added the gas, and squeezed, it pumped up. The engine immediately started without hesitation. Any ideas on why the primer would collapse? It has not done it since, but I am concerned whether I still have a fuel issue. I looked for anything that would block fuel flow, and did not see anything. Am I correct that if the primer collapsed, there was some kind of blockage? I read the number of the old sender but could not find anything on the internet, and BW doesn't really help with the older boats. also noticed the temp sender barely ever moves. Suspecting that sender is fouled, but the engine runs cool and I have tested the head temps and all are reasonable. I tested the temp and fuel gauges and they respond to open and shorted wires.
Posted by Phil T on 08/18/23 - 10:27 AM
#2
You have a fuel issue so stick to that.
Check the vent line.
Replace the primer bulb with a OEM brand (no aftermarket). Arrow pointing to the engine.
Did you replace the float or just the sender?
www.liquidlevels.net has the OEM senders.
Posted by jmlamia on 08/18/23 - 10:37 AM
#3
Thank you for the link to the OEM senders. I had looked but never saw that Vendor. They put an aftermarket fuel line kit so that may be the issue. I did replace the entire Float and sender mechanism. It seems to be accurate now so that is why I suspect the fuel system caused the NO START when the bulb was stuck deflated.
I will order an OEM line and redo it.
Posted by Phil T on 08/18/23 - 10:41 AM
#4
You can buy the alcohol resistant marine fuel hose by the foot, primer bulb and hose clamps and build it yourself.