1987 Mercruiser 165 stalling after warm up

[asa]

Ok this is my first post. I need help with an engine problem. I have a 165 mercruiser it begins to back fire and loss of power after about 45 minutes of running. It will start up and run great for about 45 minutes. I have had the carb rebuilt 2 months ago the guy used an automotive rebuild kit. I have replaced the coil (automotive coil and, automotive points). I was thinking it was vapor locking on me and I discovered it has a water cooled fuel line installed. I read in a service bulletin that this was a sollution to vapor locking on these engines so I hooked that up and it seemed to help but I still have the same problem. If I take the hood off the engine it seems to run fine. I still have a full tank of fuel but I know it is old even though I fill the tank every time I try to take it back out to see if I have it fixed yet. Maybe has 10 gal of fresh gas in. I was thinking maybe fuel pump but it read 7 pounds of pressure when I checked that. Any one with any ideas of what to try next?

Asa

 

[myfirstboat1982galaxy]

Re: 1987 Mercruiser 165 stalling after warm up

When your down and in trouble, and you need a helping hand,
And nothing o nothings going right,

You have to clean up tune up this one.

The engine is stalling after warm up is caused by passages of the engine being restricted flow ,. I would suggest sea foam in the gas. Run it light till some of the fuel gets into the engine, then shut the engine off and while it is still hot open up the air filter and clean the carb a little with some carb cleaner. Change the fuel filter . Good luck and happy fishing.

 

[myfirstboat1982galaxy]

Re: 1987 Mercruiser 165 stalling after warm up

[/QUOTE]still have a full tank of fuel but I know it is old even though I fill the tank every time I try to take it back out to see if I have it fixed yet.[/QUOTE]



You have to get a shop vac and get it all out, Then with that gas mix it slowly with fresh expensive grade gas . Then use in the snowblower this winter or the lawn mower the rest of summer.

Get a bunch of fresh gas and put sea foam in it. The engine will be running on a dime when u run through half that tank of gas.

 

[asa]

Re: 1987 Mercruiser 165 stalling after warm up

Where do I get Sea Foam? And what is this? never heard of this stuff. Ok never mind about this post . I looked sea foam and where to buy. I will get some and try that. I will also empty my tank and put fresh fuel in. I will let you know how it works. Any other ideas to try??

 

[guyaverage]

Re: 1987 Mercruiser 165 stalling after warm up

You have to get a shop vac and get it all out

WTF?!?

 

[myfirstboat1982galaxy]

Re: 1987 Mercruiser 165 stalling after warm up

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[myfirstboat1982galaxy]

Re: 1987 Mercruiser 165 stalling after warm up

Where do I get Sea Foam? And what is this? never heard of this stuff. Ok never mind about this post . I looked sea foam and where to buy. I will get some and try that. I will also empty my tank and put fresh fuel in. I will let you know how it works. Any other ideas to try??

Hey bud go to autozone and buy it for 9.99$ while your there get a oil change special even if you dont need it have it for next time. This will take your purchase over 20$ and will earn you a point on your reward card. 5 points on card and you have a free 20$ No store in the world gives you 20$ every time you spend 100$ no one can touch autozone.

p.s Autozone,Advanced,Murrys, etc al have the same parts wih most if not all having the same part number.
Just different pricing, now dont get me wrong advanced has carried stuff thaT AUTO doesnt etc which makes them different. But auto stands alone with 20$ for every 100$ if you buy in 20$ intervals. Unfortunatly you can spend 100$ at once and you only get one punch.

 

[guyaverage]

Re: 1987 Mercruiser 165 stalling after warm up

YEah WTF if your smart enough and know how to take precautions you can do this way.

I suck my oil out every season through the garden hose connect and all my gas and otherstuff.

If your a complete fool and dont either have a Shop vac for construction grade use or accident prone then you may have issues. (look online you can learn how to safty a shopvac for this intended use. What is a shop vac supposed to do? vaccum up dust? WTF is right .. You dont know jack son.

Your spelling, grammar, and maturity are the least of your problems, dad. Recommending to others to "get a shop vac and get it all out" (with no further instruction beyond that, mind you) is idiocy supreme. Google "shop vac gasoline" and read away.

Have fun.

 

[asa]

Re: 1987 Mercruiser 165 stalling after warm up

Ok I drained the gas and got the seafoam. Took the boat out and filled the tank with 93 octane. The boat ran great for 30 minutes then started the same problem again. I also changed the plugs. It started to backfire up the carburetor. I let the engine cool for five minutes then it ran fine again for about 30 minutes. Then same problem. Anyone have ideas?

Oh buy the way I did not use a shop vac to drain the tank (know better than that)

 

[Eric 3.7LX Alpha 1]

Re: 1987 Mercruiser 165 stalling after warm up

Possible fuel tank vent blocked causing a vacuum in the tank after the 30 minutes, and fuel pump can't pull fuel out of the tank.
Test: Loosen deck fill cap see if it improves. or check the vent for a blockage.

There are correct Tools to remove fuel from a tank and they DO NOT INCLUDE A SHOP VAC!
Please do not offer advise if it is dangerous.

 

[hooks1]

Re: 1987 Mercruiser 165 stalling after warm up

If your tank has an inlet "sock" filter and there is trash in the tank it can starve the engine - I've seen this in two motorhomes and a Buick. When you shut it down the trash falls away from the filter and you are fine until it recollects. With the three cases I've seen low speed and idle were fine.

 

[asa]

Re: 1987 Mercruiser 165 stalling after warm up

The vent tube is clear and open and there is no sock on the fuel lines. The carb filter is clean.

 

[kartracer]

Re: 1987 Mercruiser 165 stalling after warm up

If I take the hood off the engine it seems to run fine. Sounds like you have a ventilation problem in your engine compartment.Too much heat built up

 

[asa]

Re: 1987 Mercruiser 165 stalling after warm up

I did discover the inlet vents were not hooked up. I hooked the two vents up and made sure the blower vents were working. It did not make a difference. I did notice yesterday that the antifreeze was blowing out of the reservoir tank. The engine temp was only around 100 degrees. I was wondering if the thermostat may be stuck partially closed. How would this cause it to lose power and backfire?

 

[hooks1]

Re: 1987 Mercruiser 165 stalling after warm up

Just speculating here: Is it possible that the vents are collapsing? They usually have a wire coil to keep them open but maybe there is a break or fold that closes when it gets hot.
Also, my bilge blower shuts off when in gear and above an idle - if yours stays on and there is a restriction in the inlet air tube you may be slowly starving the engine as suggested by kartracer.
One other observation - again, about something I don't have personal knowledge of - Someone noted in one of the fora that the thermostat does not work like an auto thermostat... perhaps with your other auto parts replacements you have one of those.