same question and 1 more

[fishyfingers]

This is my first post as I recently purchased my first boat and am in some need of information. Here's the deal:

I bought a 1975 Crestliner Fishing Admiral... aluminum boat, and shorelander trailer with a Merc 500 outboard for $1000. I was told the motor was recently tuned and that it runs well and made the trip to Canada the previous year.

Question #1:
The previous owner informed me the original motor blew and he had to replace it. I am looking for the year as the info is a little out of the norm. The transom and lower unit are the original with the SN: 5336393. He said they stayed the same and just the motor was just exchanged. There is no aluminum plate; the motor is etched MNO271121139 in multiple spots. The cowl has red highlights. I believe it is a 1969. But would like to know so that I can get a manual. It is in beautiful shape. Very clean!!


Question #2:
I am beginning to prepare the boat for spring and I wanted to run the motor to be sure it was solid. I filled the tank half-way with High Octane, mixed 50:1, and added stabil. Mixed it well.
This is when the problem came. I pumped the primer bulb and the fuel made it to the carb but with the cowl off, I could hear dripping. The gas is escaping from somewhere and it looks to me like the upper carb may have a bad gasket seal where the cover goes over the float. I'm not to savvy when it comes to carbs, but does this seem feasible? If this is the case, will an amatuer mechanic like myself be able to tackle this repair without causing more damage? Linking and Syncing and all that? The local shop said they do not repair older than 1974 but if I bring the boat over they will take a peek and give me some advice. I'll probably give a tip for the favor.
Could this leak be occuring somewhere else in close proximity?? It's difficult to see in there.

Anyway, I cleaned up the gas some... choked the motor... and turned the key. It started within 5 seconds and ran very solid. I pulled the boots off plugs 1-3 with noticable looping. Overall, I am enthralled. I just don't want it to look like the Exxon Valdez pulled away from the dock. Not to mention the risk of having fuel spilling out!!!

Any advice will be greatly appreciated. I look forward to your thoughts.

 

[fishyfingers]

Re: same question and 1 more

I was just on the Old Mercs site and I saw this:

1399-1133 Float bowl cover. Fits most Mercury models from 1956 thru early 70's (replaces original that was easily broken if filter cover was not properly seated.) $59.99


maybe this has something to do with it??...

 

[allymoss]

Re: same question and 1 more

I think I actually have a couple of those things in the picture spare. I will have to check. If you wanted one or both, I would be happy to send but im in UK and postage to US might be steep. PM if you want them.

 

[Silvertip]

Re: same question and 1 more

If the motor was tilted upward when you primed it, the fuel level in the float bowl can rise to the point where it simply overflows. Sort of like tipping your coffee cup to far. A stuck float can also cause the problem. My suggestion would be to run the motor and then recheck it to see if the problem occurs again. If it does, its rebuild time. These carbs are not complicated.

 

[Yepblaze]

Re: same question and 1 more

If you have a problem go get it fixed.


And be carefull when trying to fix it yourself, like pulling plug wires while it's running.

 

[fishyfingers]

Re: same question and 1 more

Well, I brought the boat down to the local shop and guess what... The gentleman that came out recognized the boat and motor. In fact, HE built this motor last year when the original blew. This was super cool because he was able to tell me that the carbs were rebuilt by him personally and the motor was super strong and ready to go. He said he put $850 in parts and labor into the motor and that I got it for a grand with everything was a steal. Very reassuring.
Anyway, about the leak... He said that the older motors were prone to that and all you have to do is shake it a bit and it will stop. He showed me this. He said it relates to the seating of the needle in the carb and transporting the motor and triming it. With a shake the needle will seat properly and the leak will stop.
Does this make sense? Can somebody please shed a little more light on this for me?
Thanks in advance.

 

[convincer253]

Re: same question and 1 more

sounds like that guy is putting a band aid on something that needs stitches. I recently had to rebuild the carbs on my 50 (several times in fact) when I first started working on the engine it did the same thing but now I dont have the problem. if it's coming out of the vent at the top when your priming it this is normal, (the primer bulb will push the needle off the seat and cause the bowl to over fill) if its coming out around the top of the bowl or the screw at the bottom it needs gaskets and if it's coming out of the throat of the carb something might be plugged or it may be that the guy that rebuilt them set the floats to high. But if your happy just giving your engine a little shake every time you use it just leave it. PS carb kits are about $60.00 a carb so good luck

 

[fishyfingers]

Re: same question and 1 more

thanks for the advice. It is primarily when I prime that fuel drips out, which makes me happy for what you said. There does seem to be fuel leaking in other spots because when I run with earmuffs in the driveway I have a decent amount of fuel on the ground. However, I do not see any really bad leaks.

I took the boat on the river yesterday and had a new problem.
Boat ran great at idle and slow to moderate speeds but bogged down at WOT. The fuel hoses appear to be in fine working order. According to similar threads on this site it seems that the fuel pump may be on its way out. I disconnected the line from the pump to the lower carb and tried to start the motor. It wasn't spitting fuel as I thought it would. I'm thinking its time for a pump rebuild kit.



Any ideas??
Thanks for the help!!

 

[convincer253]

Re: same question and 1 more

Typically if a jet is clogged and the gas is squirting instead of spraying the engine will have a ruff idle if it even will w/o fouling plugs (explains gas on ground if it came from exhaust). the mid range could be good or bad but wot would run fine because the engine can burn any extra fuel (most times). I'm not sure if you have an external fuel pump or if their on the side of the carbs. If their on the side of the carbs you'll get the complete kit for the pump and carbs with the kit but if its external I'd start with the pump. its cheaper and sounds a little more like your problem

 

[fishyfingers]

Re: same question and 1 more

thanks. pump is external. I ran the boat at a mid to high throttle in gear until it bogged down. Then I removed the pump. the diaphram looked fine. the check valves looked good. BUT the gaskets appeared to be wet as though they were leaking. Did not see gas come out, but maybe air is getting in. I think this may be the issue. I plan on buying a rebuild kit and will cross my fingers. Should I maybe try to use some type of liquid gasket as well when I remount the pump or will this cause an imperfect seal??

 

[convincer253]

Re: same question and 1 more

Do NOT use any other sealant. All that will do is be a pain when that little bit that gets in the pump makes its way into a carb. It is unlikely that the gasket is your problem but it may be. Don't just use the gaskets from the kit; make sure you use all the parts. I think you missed something when you inspected the pump whether it is a pinhole or a stretched diaphragm I don't know but it sounds like something is diffinatly wrong with the pump

 

[fishyfingers]

Re: same question and 1 more

thanks for the advice on the RTV. I didn't think it was a good idea. A buddy said "try it... if it doesn't work, try something else".

The diaphragm didn't appear to have any holes or tears, but did seem to be a bit stretched; (not completely flat, but a little loose). I didn't know that could be a symptom.