Mariner 75hp - Engine cut out

[tristenhill]

Hi,<br />Wondered if someone could help. I've just brought a boat with a 2 stroke Mariner 75hp (4 cylinders) believed to be mid to late 80's, no oil injection. Took it out for the first time last night.<br />When i got in the water it would start but when i then put it into reverse the engine would die. Eventually got going so could have just been a cold engine. However after running at near full throttle for 10 mins slowed down and was just chugging very slowly when the engine died. Wouldn't start again fo a long time. Eventually fired up, gave it some throttle, we started going then we lost power and the thing just stopped and wouldn't start again. I don't know much about outboards as it is my first boat but seems that maybe it could be a fuel problem - not getting through?. One thing i did notice is that when pumping the primer bulb, i believe it should get hard when full with fuel, but it doesn't seem to ever get hard - after a good few pumps it is just as soft as when i started. The only other thing is that i filled my fuel tank with 25 litres of fuel then went to add the oil but couldn't quite put 0.5 litres of oil in to give a 50:1 ratio as the tank was overflowing. Therefore the mixture might have been a bit lean, was going to add more oil when we had burnt a bit of fuel but didn't get the chance. Don't know if this could cause a problem.<br /><br />Hope someone can help.<br /><br />Regards<br />Tristen Hill.

 

[Bob H.]

Re: Mariner 75hp - Engine cut out

First a stupid question: Was the tank vent open? If you overfill the tank the vent can't vent properly. There needs to be an air gap under the vent. If the vent was open and the primer bulb doesn't get firm it can be float needles aren't shutting off flow which can usually be seen because fuel will be dumping in the carb throat or a bad check valve in the primer bulb.

 

[Vlad D Impeller]

Re: Mariner 75hp - Engine cut out

Siphon off some of the gas from the fuel tank and add the remaining oil to it,<br /><br />make sure that there is enough space in the tank for it to vent as Batis mentioned<br /><br />There is no harm done in running your motor a bit on the rich side except for some minor fouling of the plugs and a bit more smoke.