Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

[TampaBoater]

So I took out the boat today after replaceing the carb. I was cruising at 1/4 throttle, I went up to 3/4 and went for about 5 mins like this, then I slowed down, then after another 3-4 mins I went up to 3/4 throttle again, about 30 sec later the engine started to sound weird so I backed down to neutral, and the the engine shut off. After inspecting I found the hole in the pics attached, can anyone tell me if this is repairable, or will I have to rebuild the whole engine?
Thanks,
Les

 

[Bondo]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

View attachment 220542So I took out the boat today after replaceing the carb. I was cruising at 1/4 throttle, I went up to 3/4 and went for about 5 mins like this, then I slowed down, then after another 3-4 mins I went up to 3/4 throttle again, about 30 sec later the engine started to sound weird so I backed down to neutral, and the the engine shut off. After inspecting I found the hole in the pics attached, can anyone tell me if this is repairable, or will I have to rebuild the whole engine?
Thanks,
LesView attachment 220541

Ayuh,.... That's an ole Choke Stove on the exhaust cross over, inside the intake manifold,....

You could build a little steel block off plate for it, if the nuts will turn,...

Worst case, bolt on a new iron intake manifold,...

 

[TampaBoater]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Ayuh,.... That's an ole Choke Stove on the exhaust cross over, inside the intake manifold,....

You could build a little steel block off plate for it, if the nuts will turn,...

Worst case, bolt on a new iron intake manifold,...

Will the manifold busting a hole like this cause the engine to behave as described? It wont want to start now. It cranks, but it wont start. Is it loosing compression through there?

 

[Bondo]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Will the manifold busting a hole like this cause the engine to behave as described? It wont want to start now. It cranks, but it wont start. Is it loosing compression through there?

Ayuh,.... I donno if that's the Only problem ya got,....

I've never tried to start a motor with that hole uncovered,...

That'll account for the noise ya heard though,...

 

[thumpar]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

It is going to be sucking a lot of air so it could explain the no start.

 

[Bt Doctur]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Never saw a choke stove there plus it looks "angled away" from the carb. Looks more like a EGR valve

 

[dingdongs]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

You could locally prep the area and then fill with some jb weld which should be good in 30 mins then try starting again when some fuel should be sucked into the cylinders. A compression tester will give you a good indication to the health of the engine b4 throwing big money around!!!!
http://www.ebay.com/itm/JB-Weld-826...954?pt=LH_DefaultDomain_0&hash=item48586cce0a

 

[Bondo]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Never saw a choke stove there plus it looks "angled away" from the carb. Looks more like a EGR valve

Ayuh,... I think yer Right, it's an ole automotive intake,....

 

[Walt T]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Egr fits the symptoms. I thought it was an old choke stove too.

 

[TampaBoater]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Update.
I manages to remove all the welding points, and 1 screw, I had to cut the other one. For those who said Choke stove, you were right. I pulled out the 2 tubes protruding, and out came a u shaped tube, looks like the burners inside an oven, so I am guessing that used to heat up and warm up the choke. I went to home depot, got me a piece of steel flat bar, about roughly 1/8 thickness, and exactly the with I needed. Grinded up the locations, slap on some JB Weld (stuff is awesome, used it before to seal another hole).. and now waiting for it to cure, and a test fire later. Fingers crossed.

 

[Maclin]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Looks like it is at the back of the manifold, if so then that is EGR and the tubing would have gone to some exhaust fittings. Also that would explain both the noise and the running symptoms you described. Plugging it like that should be ok. Just be advised that in the past someone rigged the engine improperly. It may not even have a Marine carb on it, just sayin'

 

[TampaBoater]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Its not quite in the back. It right under the electrix choke housing on the carb. It did have a marine carb on before because I looked up the serial and it was a mercarb 2bbl. Anyways I hope the patch job solves the problem. I also replaced the thermostat and stat gasket. Will replace impeller with kit.

 

[Bondo]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Update.
I manages to remove all the welding points, and 1 screw, I had to cut the other one. For those who said Choke stove, you were right. I pulled out the 2 tubes protruding, and out came a u shaped tube, looks like the burners inside an oven, so I am guessing that used to heat up and warm up the choke. I went to home depot, got me a piece of steel flat bar, about roughly 1/8 thickness, and exactly the with I needed. Grinded up the locations, slap on some JB Weld (stuff is awesome, used it before to seal another hole).. and now waiting for it to cure, and a test fire later. Fingers crossed.

Ayuh,.... I donno how well that's gonna hold up to the Heat,..??...

 

[fat fanny]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Why don't you just re-drill and tap a few more hole in a different location to mount the plate?

 

[TampaBoater]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Bondo. After 2 days of curing it is shut solid. I will probably still take it to the local welding shop to re-enforce.
Fat Fanny. There is no more room to drill any holes at that actual port.

 

[Walt T]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Don't weld it. You'll need a new manifold if you do that. The slightest warpage and it's junk. Heck what have you got to lose, try the jb weld. If it doesn't hold, get another manifold from a wrecking yard.

 

[Speakrdude]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

If it sucked that amount of air while you were under way, you may have caused a horrible lean condition and caused other damage. That would explain a non start condition. Other test need to be done.

 

[Speakrdude]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Although, that looks like an exhaust leak...(EGR..duh) Carry on...

 

[TampaBoater]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Don't weld it. You'll need a new manifold if you do that. The slightest warpage and it's junk. Heck what have you got to lose, try the jb weld. If it doesn't hold, get another manifold from a wrecking yard.

Walt, I havent weld it yet, just with JB Weld. I tried to start the engine after 2 days of curing, and it fired right up. Now I have to take it to the water for a trial run, but supposedly JB weld is good for up to 550F.

 

[Bondo]

Re: Mercruiser GM 305 5.0L hole in the motor, repairable? What's my damage?

Walt, I havent weld it yet, just with JB Weld. I tried to start the engine after 2 days of curing, and it fired right up. Now I have to take it to the water for a trial run, but supposedly JB weld is good for up to 550F.

Ayuh,.... 'n yer exhaust flows run up to 1200?,....

Weldin' is Not an option, really, it's cast iron,.... Brazin' is a possibility,...