Mercruiser 165 wont rev in gear.

[npliam]

Ok, long story but here goes.....

1 have a 1977 sea star with a mercruiser 165. This is the 3rd year I have owned it and the other 2 years it has run great.

It was hard to start this spring and didn't run great when. I did get it going. Ran some sea foam and that helped but it still didn't run great.

My wife had it out and when she went to the marina to fill up she knocked the fuel vent cover off the boat (apparently she didn't know she hit the dock that hard) and after about 3 minutes of pulling a tube it died.

I did t know that the cover had been knocked off but we towed it back to the dock and I tool the fuel filter off a d replaced it and took the carburetor apart and put it back together.

It ran fine until I made a sharp left turn and then it died again. It is at this point she told me that she hit the dock hard enough to knock off a (chrome cover) a part but she didn't know what that meant.

I realized that there water in fuel and took the filter and carb off and drained them and then put it all back together and it started just fine.

Next time we.went to the lake it would hardly idle, shift and when you accelerate it would bog before it would pull a skier out of the water.

I ordered a new carb, new distributor, new rotor new plug and plug wires and replaced them all. I hooked up the ear muffs and it started right up and would rev.up. it idled good would stay idled in gear. I felt great about taking it to the lake and was excited to have it running again.

It stared right up in the water but died when I put it in reverse. After 5 minutes I got it started when I got past the no wake zone it went a whopping 8mph.

While changing nothing it eventually (10 minutes with the throttle wide open I got it to hit 2000 rpm and 12 mph.

Frustrated, I killed the motor and dropped my trolling motor into the water and fished for a while.
I started the motor (it fired right up) and let it run for the last 10-15 min of fishing. On the way back to the boat ramp I got it on plane and we could 18 mph at almost 3000rpm

I don't what to do, I am so frustrated that it doesn't run well.

Any help would be appreciated

 

[Scott Danforth]

Check the contents of the fuel filter for water/contaminates in a clear container

Check compression

Set dwell and timing to spec

Stop spending money on parts and start trouble shooting.

If you bought your carb and other parts off of Amazon, hopefully you have the originals. Amazon parts are usually junk

Rebuild the original carb. Service the original distributor.

 

[FarmYard]

Pull spark plug closest to transom and have a look in the hole to see if there is water in the cylinder. If there is its time for a new manifold and riser. I would also do a compression test. I just went through this.

 

[ThomW]

Did you ever fully drain the fuel tank? You said you suspected water in the fuel due to missing the vent cap...and that you removed the filter and carb...but if you didn't empty the tank...which may have a good amount of water in it...you are going to keep having the same issues...namely, fuel in your gas. Pump out the fuel tank. Clean the carb. Empty fuel filter. New gas in tank and see what happens.

I also agree with Scott. Clean up the original carb and put that one back on.

 

[Bondo]

Ayuh,.... Welcome Aboard,..... I agree with the above,.... Yer still fighting the water in yer fuel tank,.....
'n you've filled that new carb with water, 'n crud,....

You don't need to drain the whole tank, but you need to come up with a way to suck all the water, 'n crud off the bottom of the tank,....

Then Rebuild one of yer carbs,....