1997 3.0 having stalling issues half way through summer

[oddcarout]

Been using my boat with a 3.0 this summer and this week it has started hesitating when trying to accelerate. It will straight die if I don’t punch the throttle at least 3/4 wot. This happens in neutral or in gear.

what I have done:

new fuel/water separator filter
new spark plugs
new gas
new anti-siphon valve
cleaned the carb with spray cleaner

have checked, I get good spray from the priming pump

Any help suggestions would be great. We have a trip planned this weekend and hope to be on it.

thank you,
zachariah

1997 Maxim 1900 mercruiser 3.0 LX

 

[dubs283]

cleaned the carb with spray cleaner

you sprayed the carb down with carb cleaner or you disassmbled, cleaned and reassembled the carb?

new spark plugs, but what about cap/rotor, wires, fuel pump filter, check and set timing/idle?

 

[oddcarout]

Sprayed the carb did not take it off, can’t tune a carb

changed the fuel/water separator filter

didnt touch the distributor since it is not loose it does not make sense to adjust it, and the cap looks fine, almost no wear.

the old plugs were gapped at .050 but the carb cover said .035 so I gapped the new ones to .035.

 

[dubs283]

can’t tune a carb...didnt touch the distributor since it is not loose it does not make sense to adjust it, and the cap looks fine, almost no wear.

carburetors most definitely can be disassembled cleaned and tuned

just because the distributor isn't loose does not mean the timing is correct, there is a special procedure for checking and setting the timing for that ignition system

looks mean nothing, when was the dist cap/rotor last replaced?

 

[oddcarout]

It got a new cap may 2019, probably has less than 50 hours on it.

what do I need (tools) to check the timing. I will look up the process.

I don’t have any issue at speed, at WOT or crushing. Just the acceleration. Would I still have a timing issue?

 

[oddcarout]

Also can anyone how to check if the power valve is stuck closed?

 

[oddcarout]

How do I check the timing? I can’t seem to find it in the manual without removing the engine.

thank you

 

[nola mike]

The timing procedure can be found in the manual at boatinfo.no. I believe that that's one of the distributors that needs to be set to "base mode" by jumping 2 wires. After that you just need a timing light.

But agreed sounds like a fuel issue. Spraying carb cleaner does nothing (unless the carb is disassembled). You need to take apart and rebuild the carb, which is also where you'll find the power valve.

 

[oddcarout]

Finally got to boatinfo.no, had to get off the network and use my cell data as it is an unsecured site. And unless I am somehow missing it manuals only got to #4. I have the paper manual that covers 1997 but did t find the distributor timing info as I was trying to read it last night.

all I found was the cam timing.

any help would be great.

 

[dubs283]

unless I am somehow missing it manuals only got to #4.

you have to scroll the grey tab below left/right to access other manuals

you should need #13

definitely need to tear down and rebuild your carb, only way to inspect the power valve and accelerator pump

 

[oddcarout]

What does the power valve do?

my accelerator pump is working, I can see the metered fuel come out when I open the throttle.

 

[Searay205]

Its not your timing. rebuild your carburetor.

 

[oddcarout]

Thank you to everyone that helped. I wanted to check for a vacuum leak first before I pulled the carb off. My thought was to check how tight the 8 screws in the top of the carb were. They were loose. At least a half turn before any resistance. I tightened them down and did a warmup and then a small test in the driveway. No hesitation, it was there before in the driveway as it was on the water. Water test this weekend but I feeling better.

thank you. Thank you thank you!!!!