nickjaxe
New member
Fixed my Yam\\mariner 55
Hope this may be of help to others, had a strange fault on my yamm 55hp would not idle did not run very well at all at low power, tryed giving the hand primer a few pumps made it worse, but ran brill at full power, at low power bottom plug fouled all the time, luckly reading the manual the was a small peice about the fuel pump diaphragm being holed, the more I thought about it it made sence, took of the pump sure enough big split in the diaphragm letting neat fuel into the engine casing so flooding the cld at low power, it could not burn it there was that much going in, at high power it could, think it may have been going for some time, if it failed at sea you can by pass the pump but will have to hand prime all the way home, good job I spoted it in the manual would never have thought of that one.
Nick in cheshire.
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Hope this may be of help to others, had a strange fault on my yamm 55hp would not idle did not run very well at all at low power, tryed giving the hand primer a few pumps made it worse, but ran brill at full power, at low power bottom plug fouled all the time, luckly reading the manual the was a small peice about the fuel pump diaphragm being holed, the more I thought about it it made sence, took of the pump sure enough big split in the diaphragm letting neat fuel into the engine casing so flooding the cld at low power, it could not burn it there was that much going in, at high power it could, think it may have been going for some time, if it failed at sea you can by pass the pump but will have to hand prime all the way home, good job I spoted it in the manual would never have thought of that one.
Nick in cheshire.
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