mercury 500 thunderbolt 50hp

[megafish]

hi there all ye great people.. i am at the end of a long line regards my ouyboard need some help please...
i bought my first fishing boat with engine included.. the engine is a mercury 500 thunderbolt 50 hp... i have a number of question need answering thanks again...
1 what year is the engine... serial no... is 9108302...
2 had the engine rebuilt ..new impellers. gaskets..seal..fuel lines.. almost everthing..
3 the problem i am having is the engine will not stay running it takes a good few turns to get it going.. when it goes the reves take off like a bat out of hell.. when i reduce the trottle lever it will not stay idel.. also if i pust the choke button the engine will kick in again.. but if i dont push the coke button the engine will die..
4 i have also got the carbs cleaned. new gaskets and seal..
5 fuel pumb aslo got cleaned and check.....

please help.. please help...

i live in ireland and it is very had to get someone to look at it.. the only person i can find is a 6 hour drive round trip.....
many thanks........

 

[Laddies]

Re: mercury 500 thunderbolt 50hp

Your engine was built in Belgium in 1976 and if you have been paying for service you need a new mechanic. Your engine is lean, that could be adjustment or dirty carbs, in as much as the were supposed to be off the engine and cleaned I would look very carefully at the engine synchronization also while the driver is off for the carbs check the cap and rotor for cleanliness, both items are nla. so use care. I wash them with dish soap and hot water and they are good as new in most cases.

 

[outboardnut]

Re: mercury 500 thunderbolt 50hp

Also seen bad primer bulbs cause this...make sure you have a good quality primer bulb, such as Sierra.

 

[megafish]

Re: mercury 500 thunderbolt 50hp

Also seen bad primer bulbs cause this...make sure you have a good quality primer bulb, such as Sierra.

thanks outboardnut... i have also replaced the primer pulb with a new one plus all new fuel lines..... can you suggest anything else i can do or check....