Gm 305 intake manifold gasket problem

[sarantis]

Hello everybody,
When i speed up (Sea Ray 1978 gm305 228HP) the temperature doesn't ecxeed the center of the meter but i can smell and see some smoke coming out from the edge of the intake manifold starboard at the center (among the two bolts,close to the automatic choke)and when this happens although the temperature is not high the metal of the intake manifold only around this area is very hot ,you can't touch it .A friend not expert told me that the gasket is burnt at that point(enough logical) and that's why the metal becomes so hot(i can understand that). Last season i had high temperatures specially at the center of the exhaust manifold starboard and i think that due to that the intake manifold gasket was affected.
So,may you tell me a)do you believe that the leaking of the gasket causes the high temp. of the metal or something else makes the metal so hot and burnt the gasket at that point? b)in order to change the gasket do i have to dissasemble the carburator and the distributor? c)is something i have to pay attention to in order to change the gasket?

 

[xltier]

Re: Gm 305 intake manifold gasket problem

its probably where the exhaust crossover passage is.its design is to heat the bottom of the carb base in winter on auto engines plus heat the choke spring.you look at any v motor you will see the paint burnt off there on the intake.my boat has a 305 also and it does that.hth

 

[Bondo]

Re: Gm 305 intake manifold gasket problem

Ayuh,......... That's pretty Normal.......

The Smoke should stop after the paint is burnt,....... Unless you're leaking something on it......

a),..... Nope......
b),..... Ayuh,........ That stuff is All in your way............
c),..... Ayuh,......... That's pretty Important Too...........

 

[88wellcraft]

Re: Gm 305 intake manifold gasket problem

Probably wouldn't be a bad idea to check the engine temp with an infrared thermometer...just to make sure your gauge is reading correctly.

 

[sarantis]

Re: Gm 305 intake manifold gasket problem

Thanks all of you for replying.
Bond O you mean I may not have probem and the gasket may doesn't need replacing? If the smoke doesn't stop should I replace it?Please try to be a little more clear(my native language isn't english).