Please Help! mercruiser 170hp I/O 1986 four winns stalls and stalling

I am not a mechanic however I love the sea, I hope someone out there can helpme. I purchased a boat 3 months ago and heres the deal, I have a 170HP mercruiser I/O 1986 Four winns.
The boat runs and starts great however when I start to plane or pick up some speed the boat automaticly dies out, and I can smell gas or fumes when this dies out as if it was fluiding out. So I changed the fuel filter and gas fuilter both were very dirty and nasty, along with the impeller and the outdrive water pump because it was over heating before this issue, that is no longer an issue. I also put new spark plugs in. I only owned the boat for 3 months and this has been the problem since I bought it. I can troll or idle all day long with no problems but once I give her some gas and pick up speed the boat stalls out. I can restart her no problem, sometimes I have to wait a minute after the stall and I can drive slowely with no problem again. I do have a small leak in the front of the motor that leaks anti freeze/water but thats just a small amount. Does any one have any ideas why its stalling when I give some speed but I can drive slow for hours?

Re: Please Help! mercruiser 170hp I/O 1986 four winns stalls and stalling

The boat runs and starts great however when I start to plane or pick up some speed the boat automaticly dies out, and I can smell gas or fumes when this dies out as if it was fluiding out. So I changed the fuel filter and gas fuilter both were very dirty and nasty

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There is your problem. The dirty and nasty stuff is probably got the carb clogged up. At idle on muffs, you have very little fuel flow. When under load and trying to get on plane, you are probably sucking water and dirt, not gas.
Clean the tank, fuel system, and carb and it will probably work fine.

Not exactly sure what "fluiding out" refers to.

Re: Please Help! mercruiser 170hp I/O 1986 four winns stalls and stalling

Do a search on 470s in the forum...it will provide you with a large volume of information. That small amount of antifreeze leaking from the "weep hole" of your water pump is a problem. You have a leaking seal that needs to be replaced before you start leaking the coolant into your oil.

Inability to plane......first guess would be carb...might be time for a rebuild.

Best of Luck...and please do a search on your motor. It is atypical and has some maintenance items to watch for that you don't for other I/Os. You have already learned about the camshaft seal leak and need to address that one soon.

Take care,

Re: Please Help! mercruiser 170hp I/O 1986 four winns stalls and stalling

Don S said:

There is your problem. The dirty and nasty stuff is probably got the carb clogged up. At idle on muffs, you have very little fuel flow. When under load and trying to get on plane, you are probably sucking water and dirt, not gas.
Clean the tank, fuel system, and carb and it will probably work fine.

Not exactly sure what "fluiding out" refers to.

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any suggestions on how to clean the tank, full system and carb?

Re: Please Help! mercruiser 170hp I/O 1986 four winns stalls and stalling

kparsells;

I have the same engine and have had the same problems over the years. Don S. is right...you need to rebuild your carb, drain your fuel, replace the fuel filters & separator if you have one. Go here and download the manual for your engine;

http://forums.iboats.com/showthread.php?p=1693398#post 1693398

It will have all of the answers you're looking for. The carb rebuild kit comes with instructions as well.

You'll need the serial number off of the carb to buy the right kit, it's stamped on the face of the carb, and/or on an aluminum tag on the top of the carb. The number will likely start with 170 or 70. Then follow the instructions to a tee. It's not difficult, but you have to pay attention to detail...no shortcuts. You can get the kits here at iboats.

Here's a good article on the leaking coolant you mentioned, and yes, it will be a problem if you let it go. http://www.sterndrives.com/470_coolant_leak.html

The fumes you smell when your boat dies may just be exhaust washing forward from the abrupt halt. If it smells like raw fuel, then you have to find out where it's coming from...that's not good either !!!

Re: Please Help! mercruiser 170hp I/O 1986 four winns stalls and stalling

rebuild carb and dont worry about the tank. keep extra fuel filter on your boat and tools to chang it.