1995 3.0lx multiple head gaskets

[maxum1700]

Hello! I am new here, just picked up a 95 Maxum 1700sr with a 3.0lx. The head gasket blew first time out, I replaced and took out again. Did fine for two days, them blew cylinder 3 again. I know I did not perform the timing procedure correctly. I now have the tool and will be reassembling today. My questions are, the manual I have states head bolts are 65 ft lbs torque. I am seeing other people say it is 90. Can anyone verify? Also what is the best way to get the fuel mixture correct? would I be better off with a vac gauge hooked up? Serial number is 0f452487. The head and block are good. Straight edge checked.
Any advise would be much appreciated.
Have a good day folks.

 

[alldodge]

Blowing the same place would tell me the head or block is not flat within .003

Yes head bolts torque 90 ft lb, and to retorque after first 10 hours (manual 13)
65 ft lb is for flywheel and main bearing bolts

Final Idle Speed and Mixture
IMPORTANT: Boat must be in the water and engine
at normal operating temperature to accurately
check and adjust idle speed and mixture.
Carburetor should be set so that engine idles smoothly
within range given under “Specifications,” with boat
in the water, engine at normal operating temperature
and drive unit in forward gear. To adjust idle speed
and mixture, proceed as follows:
IMPORTANT: DO NOT attempt to compensate for
other engine problems (incorrect ignition timing,
faulty ignition components, low compression,
vacuum leaks, etc.) with carburetor adjustments.
This will only cover the problem, which must be
corrected if engine is to achieve maximum fuel
economy and performance.
1. Connect an accurate shop tachometer to engine.
2. If new or rebuilt carburetor has been installed,
turn idle mixture needle in (clockwise) until it lightly
contacts seat, then back out needle 1-1/4 turns.
This will provide a sufficient setting to allow starting
engine.
3. Start engine and run at 1500 RPM until engine
reaches normal operating temperature.

4. With boat in open water, place remote control in
forward gear, idle position.
5. Disconnect throttle cable barrel from anchor stud.
Be sure not to lose spacer on anchor stud.
6. Adjust idle speed adjustment screw to obtain
550-600 RPM, in neutral gear.
7. With engine running at specified RPM, adjust idle
mixture needle as follows:
a. Turn idle mixture needle in (clockwise) until
the engine speed begins to drop due to lean
mixture.
b. Turn idle mixture screw out (counterclockwise)
until the speed begins to drop due to rich
mixture.
c. Turn screw in to a point between these two extremes
to obtain maximum engine smoothness
and RPM.
d. Readjust idle speed adjustment screw until
engine idles at 650-700 RPM in forward gear.

 

[maxum1700]

Thank you for the feedback. I should have stated that the first gasket blew 3 and 4. The second was 3 only, I only torqued to 65. I will try again. I read the same info as you posted about adjusting the carb. I am looking for a few tips on getting it right.

 

[Rick Stephens]

Blowing the same place would tell me the head or block is not flat within .003

Yes head bolts torque 90 ft lb, and to retorque after first 10 hours (manual 13)
65 ft lb is for flywheel and main bearing bolts

Final Idle Speed and Mixture
IMPORTANT: Boat must be in the water and engine
at normal operating temperature to accurately
check and adjust idle speed and mixture.
Carburetor should be set so that engine idles smoothly
within range given under “Specifications,” with boat
in the water, engine at normal operating temperature
and drive unit in forward gear. To adjust idle speed
and mixture, proceed as follows:
IMPORTANT: DO NOT attempt to compensate for
other engine problems (incorrect ignition timing,
faulty ignition components, low compression,
vacuum leaks, etc.) with carburetor adjustments.
This will only cover the problem, which must be
corrected if engine is to achieve maximum fuel
economy and performance.
1. Connect an accurate shop tachometer to engine.
2. If new or rebuilt carburetor has been installed,
turn idle mixture needle in (clockwise) until it lightly
contacts seat, then back out needle 1-1/4 turns.
This will provide a sufficient setting to allow starting
engine.
3. Start engine and run at 1500 RPM until engine
reaches normal operating temperature.

4. With boat in open water, place remote control in
forward gear, idle position.
5. Disconnect throttle cable barrel from anchor stud.
Be sure not to lose spacer on anchor stud.
6. Adjust idle speed adjustment screw to obtain
550-600 RPM, in neutral gear.
7. With engine running at specified RPM, adjust idle
mixture needle as follows:
a. Turn idle mixture needle in (clockwise) until
the engine speed begins to drop due to lean
mixture.
b. Turn idle mixture screw out (counterclockwise)
until the speed begins to drop due to rich
mixture.
c. Turn screw in to a point between these two extremes
to obtain maximum engine smoothness
and RPM.
d. Readjust idle speed adjustment screw until
engine idles at 650-700 RPM in forward gear.

AD, those instructions contradict themselves. First it says to be in gear, then it says to make the adjustments in neutral. Then it says to readjust idle speed in gear. Seems it is just as right to do all the mixture adjustments on muffs and then do a final idle speed set in gear in the wet.

 

[alldodge]

If rebuild adjustments have been done to specs. I disconnect carb linkage place in gear out in the water or tied to dock. Motor all warmed up turn adjuster in until it starts to stumble, then back out until rpms are correct. Leave it there going in/out of gear several times seeing if there are any changes. Readjust if needed.

 

[Bt Doctur]

Make sure you tighten in atleast 4 steps 20-40-60-90

 

[Lou C]

And clean cyl head bolt holes in the block with a thread chaser, carb cleaner & compressed air. Make sure each head bolt will thread in all the way before installing the head. If not you won’t get adequate clamping strength. And make sure the cyl head bolts threads are clean and free of rust, if they are questionable replace them. I replaced mine when I did my top end overhaul with ARP head bolts. Lastly follow instructions about using sealer on the bolts if needed. It is on the V6 and V8. I used Permatex Aviation.

 

[Scott Danforth]

for ARP fasteners, they only list head studs for the 2.5/3.0. at $190 its way too much over a set of $40 GM/mahle head bolts

an alternative to ARP head bolts is to buy an ARP BBC 2-bolt main bolt kit and go that route. you will need to toss the washers same $40 price, kit # 135-5002

the other thing, the head and deck needs to be extremely clean. I spent an hour with a bunch of rol-loc 3M wheels cleaning the deck and had the head surfaced after squirting the second head gasket.

BTW, if you are running higher than 4600 RPM, look at your prop pitch.