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Starving fuel

Z

zum

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"Wow,I must of googled for ser

"Wow,I must of googled for serial number(year) information 100's of times and never found this site.
Mr.G.Lamb you seem to be the man when looking for this infomation,so I'd like to thank you in advance.
My motor is 30ML 689 L 328778 Made in Japan,by reading this thread I'm thinking around 85-87 year outboard ,would this be correct?
The outboard works fine at first then it starts to die at WOT,I took the cowl off and noticed it was not getting it's fuel so when I pump the ball it will run fine.Was wondering if it could be as simple as lines or a bad ball or should I be looking at the fuel pump?This is why I need the year so I can look for pump parts ,thanks.

I tried to delete a post in someone elses question but I was to late,so sorry if this is a double post."
 
"seems u have answered your qu

"seems u have answered your question yourself, if u have to squeeze the prime bulb for it to run correctly it means the carby isnt getting sufficient fuel, it could be a number of issues, i'd start by testing the fuel line and primer bulb, if it pumps up hard and then losses pressure in the bulb it is probably worn out, if so try replacing the fuel line from the tank to the engine including the primer bulb, also thoroughly inspect all fuel lines from coupling at front to fuel pump and from fuel pump to
carb(s) also replace if they feel brittle or hard on surface as they are subjected to heat and do perish underneath the soft braiding. A pinhole in line can cause lack of vacuum in line to stop fuel pressuring up. If this doesnt relieve the problem i would then be looking at fuel pump diaghram and poppet valves for replacement, also do a compression test on engine as fuel pump relies on compression from cylinders to function correctly. Hoepfully Mr Lamb will be along soon to give you the info on model number year for the engine, i unfortuantely have had a recent PC meltdown and have lost all my data relevant to marine engine ser no#'s etc."
 
Thank you for the posts and th

Thank you for the posts and the link.
This motor wasn't run in a few years when I bought it.I did a compression check(125psi both)All I had to do was clean the carb and change the plugs to get it to run.I should of checked the fuel pump but I think I'll try the fuel line and ball first.
Thanks again for the help.
 
Hi there!

Welcome to the fo

Hi there!

Welcome to the forum! Ye Olde Sea Dawgs here will help tirelessly!

Don't forget to check / replace the impeller and lower case lube as a matter of course.

Gas:eek:il mix must be 50:1.

Regards from a cold and wintery Johannesburg in South Africa!

Benjamin.
 
"Thanks again,sorry forgot to

"Thanks again,sorry forgot to mention I checked the impellor put compressed air through the pee hole and changed the lower unit oil.It never had a thermostat in it,I wasn't sure if it needed one;went to a repair shop and he "found"one out of a junked outboard,put it in seems to work fine.Havn't been to town yet to try a new ball(line),maybe Monday.
When I think of South Africa or Australia,cold and wintery isn't the picture.From hot and muggy Nova Scotia,Canada."
 
"Sorry John, been away for a f

"Sorry John, been away for a few days. You have a 1986 Yamaha built "A" model Mariner.

Your model was essentially Yamaha's own 30 horse motor that was produced by them between 1979-85.

A significant number of parts is still available through a Merc dealer, however, would assume that if you also have a Yami dealer anywhere nearby they could help you out as well if you are ever looking.

A well designed/built motor aimed primarily at the Asian/European market, a number of 30 and 40 horse Japanese Mariners made it to North America because of their immense popularity..."
 
"I disconnected the fuel line

"I disconnected the fuel line at the carb.and pulled the outboard over acouple times,fuel came out;I'm not sure if it's enough fuel and before I buy a new fuel pump I think I should replace the ball and line.Is there a pressure gauge to check fuel pumps(i imagine there is)and how about checking the ball and line?"
 
"Hi there,

Rub it in... It&

"Hi there,

Rub it in... It's very cold here today, had 5 deg's this morning on the car's outside temp reading... But the seasons are turning and we'll be laughing at you in two month's time... Roll on SUMMER!!!!

Ball should hold pressure when pumped up, motor off. Fuel line is a visual check for cracks and so on. Connectors could have suspect seals, and leak air.

Not too sure where to find a pressure guage or what pressure should be.

Hope this helps?

Benjamin."
 
"Just so people know the probl

"Just so people know the problem has been fixed,thanks for all your help.
It ended up just being something as simple as a cracked fuel line and diaphram on the fuel pump.
Thanks again"
 
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