Older Merc 165 hard to start after a hard run, runs rough, dies

[Fishermark]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Sounds hydrolocked to me. Pull the plugs and see if you have water in the cylinders.

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Sounds hydrolocked to me. Pull the plugs and see if you have water in the cylinders.

Just pull all the plugs and try to crank it again to see if water comes out ? What are some reasons water will be in the cylinders ? (sorry for the dumb Q ).

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Choke flap should be fully open+ when running at least 20 minutes. Now you have a starter problem. Are you reading your reply posts?

What did I miss ? I'd say the choke has about 1/4 inch to the point where it can't open any more. I don't think the starter and the choke are connected somehow , or am I missing something ?

 

[achris]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

What did I miss ? I'd say the choke has about 1/4 inch to the point where it can't open any more. I don't think the starter and the choke are connected somehow , or am I missing something ?

I think he's still trying to diagnose your original fault....

Water could be in the cylinders if you have a cracked had, or a US manifold or exhaust elbow...

 

[Fishermark]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Just pull all the plugs and try to crank it again to see if water comes out ? What are some reasons water will be in the cylinders ? (sorry for the dumb Q ).

Correct. And when you pull the plugs see if they have any rust or water droplets on them.

Like Chris mentions, the water can get in from various sources. Find out if that is the problem, then you can find out where it is coming from. Also check you oil to see if it is milky or the level has increased.

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Here's an update on the boat:

1. Pulled the starter off, had it checked, IT'S TOAST ! Max allowed AMP draw is 150, this thing was at 335 AMPS. The thing also sounded like a blender with a cup of stainless steel nuts in it.

2. Pulled the plugs, they look nice and clean. No oil, no fuel, no water droplets, no rust. Couldn't turn the engine to see if water came out since the starter is gone.

3. Oil level is at MAX line, even after about 15 hrs of work. Looks a nice, clean, brownish color, as if it just came out of a can.

At this point I'm just cleaning up terminals, wires, connections, etc while waiting for the new starter to come in. Autozone ordered it (3 business days away). It's a brand new Sierra, one year warranty for $156 (tax included). The good thing is, I get to keep the oldie starter for parts.

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Should take it in to a Merc mechanic to check out your choking system. It's ether not working properly or adjusted wrong.
Re: Older Merc 165 hard to start after a hard run, runs rough, dies . If you don't get your original problem solved you could possibly go through another starter by the end of the summer. Not good to overheat a starter.

 

[achris]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Should take it in to a Merc mechanic to check out your choking system. It's ether not working properly or adjusted wrong....

Or just use the manual and adjust it yourself.... It's just loosen the 3 screws on the choke element housing and turn it slightly... :facepalm:

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Here are a couple of pictures of a carb I have of the 165. The second picture is the adjustment is all the way open, you can see the flap open, I undid the screws and and turned off the choke. I hi-lighted the choke assembly with whiteout so you can see better. The first picture is set at the center in the cold position (not how my was set). I taped on the choke heat riser to show that the heat from the intake manifold rises up to heat a coil inside the choke assembly and opens the flap but not much range (on my motor).

Ok. the motor is cold now, go out and check how much tension is on the flat to close. It should be lightly closed or slightly open. You will have to shift into forward to engage the choke because the linkage is lock at N. If it is tightly closed you have it out of adjustment.
I have been through the same problem. It can be tricky because of the old style heat rise. Go through the most simple ways of elimination.
I still suggest you take it in and have it looked at. The inline 6 is a very simple motor to work on.
Wish you the best

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Here are a couple of pictures of a carb I have of the 165....

Riptorn , those pics are amazingly helpful. Once I get back from the road, I'll check the choke operation.

At COLD, it should be almost closed, but do I have to adjust it again once the engine is warmed up or it's adjusted only at cold ? Also, last time I checked the choke at HOT motor, the flap was not in top position. Seemed like there was another 1/4 inch it could have gone to be in true vertical position. Is this how it is on your 165 also ? Thanks!

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Yes there isn't much range from open and close with the heat rise tube. I checked mine out a few times and everything was clear. Just leave a mark where it was so you can put it back (don't you will have to). Adjust at cold and then see if the flap opens up all the way. Don't forget to shift to forward (pump the gas) and back to neutral to engage the choke before you adjust or the flap will not close.
When warmed up the flap was fully open on my 165. If it isn't then after 10 minutes sitting off it will close again making it too difficult to start because it is choking off the air to the engine and causing flooding.

We are leaving for the cottage Thursday afternoon. Don't know if my net is hooked up there yet. I think my blackberry will work.

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Finally had a chance to check out the choke operation. At cold, it was open about 1/16'' which seemed like it was just right. Upon further investigation of the heat rise tube though, I noticed that it became detached from the manifold. Seems like it's just a brake/fuel line that slips into a fitting on the manifold. Well, it was out with a 1/4" gap. I'm wondering if something so small could have caused all of my problems with the rough hot starts and idle ? Seems like this might be a problem.

I just got my new starter yesterday, and didn't have a chance to put it on yet, so I can't warm the motor up to test it for sure.

Also, I'm attaching a picture of the filter that was inside of the carb intake line. Tell me what you guys think. Looks like sand but seems to me like something fuel does when it's old... (gumming?) Are these little filters re-usable or should I just get a new one ?

 

[Fishermark]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

That is bad. Yes, you can clean that filter, but I would try and find out where all that is coming from.

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

That is bad. Yes, you can clean that filter, but I would try and find out where all that is coming from.

The previous owner had the boat sitting about 8 months before I purchased her. I doubt he did anything to it to condition the fuel during that time. The other filter (in the pump bell housing) looked good.

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

You be surprised what can fall into your gas tank while filling up( leaves,bugs,sand). You need a flush and an add on fuel filter for a while, I would do.

Your heat riser is not working properly. You can't have any heat leakage at all because of the low range of the heat rising up to open the choke coil. The coil works like thermometer. No heat, no movement.
Can you get picture of the break. I don't have my 165 anymore. Should be solid pipe.

 

[riptorn]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Also, I'm attaching a picture of the filter that was inside of the carb intake line. Tell me what you guys think. Looks like sand but seems to me like something fuel does when it's old... (gumming?) Are these little filters re-usable or should I just get a new one ?

View attachment 147484

Be surprised what can fall into your gas tank while filling up( leaves,bugs,sand). You need a flush and an add on fuel filter for a while I would do.

Finally had a chance to check out the choke operation. At cold, it was open about 1/16'' which seemed like it was just right. Upon further investigation of the heat rise tube though, I noticed that it became detached from the manifold. Seems like it's just a brake/fuel line that slips into a fitting on the manifold. Well, it was out with a 1/4" gap. I'm wondering if something so small could have caused all of my problems with the rough hot starts and idle ? Seems like this might be a problem.

Your heat riser is not working properly. You can't have any heat leakage at all because of the low range of the heat rising up to open the choke coil. The coil works like thermometer. No heat, no movement.
Can you get picture of the break. I don't have my 165 anymore. Should be solid or best with NO heat loss.

 

[CaptainMak]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Finally had a chance to play around with the choke adjustment assembly (black plastic). Unscrewed the 3 small screws and took off the black, plastic cap. The spring was not even on the lever that holds the choke back. Had to turn the black cap counter-clockwise about half inch , and voila, the boat started right up although the idle was a bit high at 1000 rpm.

Still trying to figure out how the coil spring popped off the lever but happy the boat starts good, (hot AND cold) and , although idling high, still idles decent. Thanks for the help all. !

 

[ShowMeGuy]

Re: Older Merc 165 hard to start after a hard run, runs rough, dies

Finally had a chance to play around with the choke adjustment assembly (black plastic). Unscrewed the 3 small screws and took off the black, plastic cap. The spring was not even on the lever that holds the choke back. Had to turn the black cap counter-clockwise about half inch , and voila, the boat started right up although the idle was a bit high at 1000 rpm.

Still trying to figure out how the coil spring popped off the lever but happy the boat starts good, (hot AND cold) and , although idling high, still idles decent. Thanks for the help all. !

Thanks for the follow up. Glad to see it sounds like you got it worked out...