Mercruiser 165 will not go above idle in gear...

[johnsland8]

I have a Mercruiser 165, it's a transplant but I believe a late 70's vintage.
It was a project when I got it 2 years ago and finally took it to the lake for the first time yesterday.
The issue is that it will start and run fine in neutral. It will rev up through the RPM's just great and idle nice. When I put it in gear, it will ONLY idle. If I try to increase the throttle it will just die. At one point, I put it into reverse for a couple minutes. When I shifted back forward it took off and ran like I would expect it should. When I stopped and took it back into neutral, it would only go idle speed again in gear. It would just cut out and die if I tried to go any faster than idle. In neutral, it runs and revs like a champ, in gear, no go? Any ideas?
Thanks in advance for your help!

 

[JustJason]

Re: Mercruiser 165 will not go above idle in gear...

as with anything.... check your compression first.

but it sounds like you have a fuel issue.
go through your entire fuel system starting with the tank and work your way back. replacing every filter along the way.

 

[johnsland8]

Re: Mercruiser 165 will not go above idle in gear...

If it were a fuel issue why would it run so good in neutral. It revs up to 4000 rpm + and doesn't even stutter or hesitate in the least. If it were fuel I would think it would at least show some signs of it then as well, wouldn't it?

 

[bomar76]

Re: Mercruiser 165 will not go above idle in gear...

What it does in neutral is meaningless...there is no load on engine.

 

[JustJason]

Re: Mercruiser 165 will not go above idle in gear...

because the engine will rev in neutral on 1/10th of the fuel it actually needs to run under a load.

 

[mthieme]

Re: Mercruiser 165 will not go above idle in gear...

I had this happen on a 35 Merc...turned out to be the fuel pump.
Not exactly apples and oranges, but it's something to check that isn't too major.

 

[johnsland8]

Re: Mercruiser 165 will not go above idle in gear...

OK, next dumb question...
How do I simulate a load on the engine so I can check any changes I make?

 

[Fishermark]

Re: Mercruiser 165 will not go above idle in gear...

While the fuel is certainly a possibility - it also sounds like your shift interrupt is coming into play meaning a bad or misadjusted lower shift cable. I know you mention you are able to put it into gear, but I wonder if it is actually dying as a result of trying to go into gear.

Next time you have it out, try opening the engine compartment and watch the shift interrupt switch when you put it into gear. Does the switch engage and stay engaged? If so, you have a bad cable... or one that is not adjusted properly.

And before anyone points it out - Yes, I know the switch is designed only to operate when coming out of gear, but if the cable is stiff it will cause it to bind and operate when shifting INTO gear as well.

 

[chiefalen]

Re: Mercruiser 165 will not go above idle in gear...

May i ask what is idle in the water in gear right now on your boat sir?

 

[johnsland8]

Re: Mercruiser 165 will not go above idle in gear...

May i ask what is idle in the water in gear right now on your boat sir?

It idles at about 800 RPM. I could get it up to about 1000-1200, that was it.

 

[chiefalen]

Re: Mercruiser 165 will not go above idle in gear...

Am i wrong or is 650-700 in gear on the water the right rpm. On the trailer maybe ok 800 steady rpm.

Something binding the out drive? Did you pull the out drive and not use a alignment bar?

Lower cable not adjusted right?

Just thinking out loud so to speak.

 

[CAPT JACK SPARROW]

Re: Mercruiser 165 will not go above idle in gear...

I have a Mercruiser 165, it's a transplant but I believe a late 70's vintage.
It was a project when I got it 2 years ago and finally took it to the lake for the first time yesterday.
The issue is that it will start and run fine in neutral. It will rev up through the RPM's just great and idle nice. When I put it in gear, it will ONLY idle. If I try to increase the throttle it will just die. At one point, I put it into reverse for a couple minutes. When I shifted back forward it took off and ran like I would expect it should. When I stopped and took it back into neutral, it would only go idle speed again in gear. It would just cut out and die if I tried to go any faster than idle. In neutral, it runs and revs like a champ, in gear, no go? Any ideas?
Thanks in advance for your help!

STICKING OR MISAJUSTED SHIFTER CABLE!!!!!
__________________________________
!!! SOUNDS LIKE YOUR SHIFTER CABLE NEEDS AJUSTING, BECAUSE WHEN YOU PUT THE OUTDRIVE INTO GEAR, THE GEAR DOES NOT ENGAGE AND WHEN IT DOES IT IS NOT ENGAGED FULLY CAUSING IT TO LOCK UP, SO WHEN YOU SHIFTED IT INTO REVERSE THEN BACK INTO FORWARD THE SHIFTER LOCKED THE FORWARD GEAR IN TO PLACE THUS GIVING YOU FULL POWER IN FORWARD. THEN WHEN YOU PUT THE SHIFTER BACK INTO NEUTRAL IT DID NOT TRAVEL THE FULL LENGTH BECAUSE THE SHIFTER CABLE NEEDS AJUSTMENT OR ALSO THE SHIFTER CABLE COULD BE STICKING FROM THE SHIFTER UNIT TO THE OUT DRIVES UNIT::redface::

 

[bomar76]

Re: Mercruiser 165 will not go above idle in gear...

Sounds like someone needs to find the caps lock key and try to figure out what it does....

 

[johnsland8]

Re: Mercruiser 165 will not go above idle in gear...

Thank you all for the suggestions and ideas. I didn't get a chance to work on it today but I will be digging into it tomorrow and let you know what I find...

Thanks!