150 GT torque specs

[sutor623]

I have an ‘86 150 GT and I had to replace the gaskets for the exhaust cover. Does anyone know the torque specs/sequence for the re-install? Does it need gasket sealing compound? Thanks!!

 

[Joe Reeves]

If they're the new type gaskets that have a shinny reflective appearance, that's a solution that is self sealing via heat. Usually, but not always, somewhere on them you'll see a notation which says "Do Not Use Sealer". However, if they're just the regular type gasket which is obvious just by their appearance, then yes, use Gasket Sealer which comes in a can that has a small brush attached to its screw off cap.

There is no actual sequence to the tightening that I'm aware of... BUT... I always made a practice of tightening from the inside portion of the baffle plate towards the edges.

If memory serves me right, those bolts are 1/4x20.... as such, the torque would be 60-80 inch lbs.... 5-7 foot lbs.

 

[sutor623]

Thanks Joe!! As always. I had some water leaking through the outer edges of the exhaust plate so I decided to pull it. Man..... those bolts had all worked themselves kinda loose. I have seen this on multiple GT/XP models.

Since I have you on here I was wondering your opinion on voltage levels. I have seen levels up to 15.5v at 3500rpms. Does that seem a little high? Seems to lay around 14.5v at idle and high idle. Tach works good and battery is charging well.

 

[Joe Reeves]

You don't say what the voltage levels are above 3500 rpm up to full throttle but in not saying, I assume they do not exceed 15.5v . That model, if memory once again serves me right, has a voltage regulator/rectifier on top of the crankcase right to the rear of the flywheel to keep the voltage from skyrocketing... and although 14.5v is the ideal reading to obtain, a reading of one more volt wouldn't concern me... BUT.... if it starts climbing (at any rpm) up into the 17v and 18v range... then yeah, I'd be concerned about that regulator... OR...the battery.

I have heard tell and read about various batteries that just aren't compatible with the 35 amp charging system in that engine. Unfortunately I don't remember what batteries were mentioned.

 

[sutor623]

Cool thanks bud. Yea you definitely want a larger battery that can handle the amperage that is thrown at it. I think a group 27-29 start battery would be ideal.

 

[Sea Rider]

New gaskets needs to be re torqued to fact specs soon after max 5 hours has elapsed from initial installation, that's in order to sit and seal well as expected. Wll find that gaskets compresses and cedes a bit due to high operating temperature which is normal. The issue is that most boaters doesn't believe whatsoever that new gaskets needs to be re torqued for engines to work spot-on.

Happy Boating

 

[sutor623]

New gaskets needs to be re torqued to fact specs soon after max 5 hours has elapsed from initial installation, that's in order to sit and seal well as expected. Wll find that gaskets compresses and cedes a bit due to high operating temperature which is normal. The issue is that most boaters doesn't believe whatsoever that new gaskets needs to be re torqued for engines to work spot-on.

Happy Boating

Agreed!! Especially with head gaskets. I like to go a few heat/cool cycles in that first few hours.

 

[Sea Rider]

Agreed!! Especially with head gaskets. I like to go a few heat/cool cycles in that first few hours.

Would say all new gaskets needs a re torque after some heat/cool cycles. As an example. if exhaust cover gaskets are not re torqued to fact specs could have water intrusion in combustion chamber and rust piston rings and spark plug tips as has already happened.

Happy Boating