merc 500 a few questions

[bradw18]

hi everybody iv been reading these forms for a while and finally decided to register. im pertty young only 20 but iv had a boat every since i was about 13 a little 1977 polar craft jon boat with a ol 15 horse on it i took it everywhere on lake barkly in kentucky well recently i had a change to trade it for something a little better i thought :redface:

i traded it for a 1973 angler bass boat with a merc 500 on the back of it old boat is in good condition for its age. when i went and looked at it he put the ear muffs on it and it started good idled good and went into gear good. well got back home put it into the water and guess what put it in gear and it died. i was determined to make it out to the water so i idled it up and went a head and went out well the boat never got above about 10 mph ( a guess) boat never even tried to plane out. im not the best mechanic but i kno my way around a sbc. i tried puttin the choke on a little and it didnt make any diffrence i took a can of carb clean with me just incase it wouldnt start. i sprayed it into the carb and it killed it instantly. i think its running very rich but im no boat mechanic. im unsure of the year of the motor

could somebody give me a link to were i can buy a fuel pump rebuild kit and a carb rebuild kit and a link to how to do them both. im unsure how long the boat set but everything in the motor looks good im going to do a compression test today and see what it comes up with all the plugs looked good when i pulled them out today. when its in the water it idles fine just cant put it in gear it acts like it has a dead spot in it then after i get past that point it just runs like crab but id dont die or anything any help will be greatly appreciated thanks for reading
brad

 

[bradw18]

Re: merc 500 a few questions

did a compression test today it has 100 on 1 110 on 2 115 on 3 and 110 on 4 i think im good on compression any idea were i can get a carb rebuild kit anybody

 

[bradw18]

Re: merc 500 a few questions

the model number on the motor is 2107906

 

[bradw18]

Re: merc 500 a few questions

the mechanic said it was only firing on 2 cylinders... i heard on these older boat motors that the only thing that would really cause that would be a bad distributor cap and rotary button if thats true were can i find them at?

 

[Wingedwheel]

Re: merc 500 a few questions

You're getting way ahead of yourself. Look through the forums and you'll see there are plenty of posts about your same problem. that distributor and rotor are not cheap. Get a manual and do some diagnosis before you start throwing parts at it. You might be surprised at what you find.

 

[starcraft1982]

Re: merc 500 a few questions

And for gods sake,change the impeller and inspect waterpump if you havent done it yet!If its sat, its time.DONT GO FIX YOUR PROBLEM AND TORCH THE MOTOR BY OVERHEATING BECAUSE OF A $20.00 PART!Not trying to put you down.please dont take it that way.Just have read ALOT of horror stories where people who simply "didnt know"roached a motor because of this simple,VERY NECESSARY check.Change it now(impeller)and every two yrs,minimum.

 

[bradw18]

Re: merc 500 a few questions

i had it at art brothers boat repair in eddyville kentucky hes a very well known boat repair place around here. i have read a few threads on here. mines a 1967 merc 500. the miss fire is on the same 2 cylinders and 2 of the to that are firing is only half the time. he went threw it checked the carbs and all that good stuff and said it was the distributor... as for the water pump and the impeller as soon as i get it running right ill do them things next traded a ol jon boat that ran great and needed nothing for this boat and the guy said it just missed a little when he took it out hahahaha... he fooled me.

 

[merc850]

Re: merc 500 a few questions

In '67 they made 2 50's - the Merc 500S with points and the Merc 500SS with Thunderbolt ignition, no points. If it's the 500S you can clean and gap the points to .008"; if it's TB all you can do is clean the rotor tip and the wire contacts inside the cap (a Dremel wire wheel works great). New plugs would help and check the wires for spark leakage, running it in the dark helps find grounded wires.
Get a complete manual too.

 

[coolguy147]

Re: merc 500 a few questions

no dont clean the rotor and contacts in the cap. you want to keep the gap as small as possible.

if anything just use a knife wipe off some carbon. but it's all good. keep the dirt off mainly. do not scrap metal off. bigger gap= no no