yamaha 3.0 l4 blew head gasket help!

[Flashcardsgo]

Looking back at the pics, it appears silicone was slathered upon a gasket and installed. I guess that's better than nothing, but there are better sealants to use for this - but not with one that ever had silicone on it before. I'd make a gasket and put some Permatex #2 or #3 on that thing. Silicone has a tendency to lubricate gaskets, making them slip and "squirt" out between surfaces. Silicone is a great sealant to use on it's own for when there is a gap between parts, but there are superior things to use when there isn't and there is potential for a gasket to move.

If I have to take it back apart I will make another gasket out of the material I bought . I’m getting really frustrated after all my work I’ve done and not being able to find gaskets and parts it’s just real frustrating! I tried to start it today with muffs on. It was real hard to start and motor was shaking trying to start. It did start after a dozen tries but it was really loud and I didn’t let it run long. It sounded like a car with the muffler off. . I’m about ready to let it burn or a tree fall on it lol. Just kidding but I’m really having a time

 

[Flashcardsgo]

You can make that one too. One can find some gasket making sheets at most auto parts stores. I have made riser gaskets out of the thicker gray colored gasket material. Slather that thing with some Permatex #2 and it won't leak.

Hey brother. I appreciate you expertise on my body motor. It’s been a job for sure so hard to get to anything and I’ve had some bad breaks besides impossible to get parts. I thought I was over the hump after fixing the broken bolt in the manifold and reattaching the riser ( I used red permetex because it said for high heat ( exhaust ) purposes. Anyway I got it running today it was very hard to start and when it did run it was extremely loud like a car with a bad muffler. Nothings leaking at the manifold or riser or the boots . My biggest nightmare is it’s the metal piece under the boots that bolts to something under the motor. It’s totally non accessible and I have no idea how to remove it or see it or anything. If it’s broken or cracked and it can be removed I can get one from the guy I got the head , manifold etc from . It seems the only way to get to that would be pull the motor which I definitely don’t want to go down that road. Any advice , suggestions etc. thanks. Tom .

 

[kd4pbs]

Well, it will sound like a car without a muffler on the outside of the boat because literally there is no muffler. You should not hear any exhaust sound on the inside and should not see any water leaking into the bilge while running the engine on the muffs. In order to replace the gasket at the bottom of the transom assembly where the exhaust goes outside of the boat, you would indeed have to remove the engine. The exhaust on your boat should never get anywhere close to the kind of temperatures that one would see in an automobile due to the fact the exhaust system is surrounded by water jacket. The problem with using questionable sealing techniques on the riser gasket is that water might be leaking into your exhaust ports without you even knowing. Hang in there, you’ll get there eventually.

 

[Flashcardsgo]

Well, it will sound like a car without a muffler on the outside of the boat because literally there is no muffler. You should not hear any exhaust sound on the inside and should not see any water leaking into the bilge while running the engine on the muffs. In order to replace the gasket at the bottom of the transom assembly where the exhaust goes outside of the boat, you would indeed have to remove the engine. The exhaust on your boat should never get anywhere close to the kind of temperatures that one would see in an automobile due to the fact the exhaust system is surrounded by water jacket. The problem with using questionable sealing techniques on the riser gasket is that water might be leaking into your exhaust ports without you even knowing. Hang in there, you’ll get there eventually.

I started it a few minutes ago was loud. Smoking out at the outdrive and idling way too high like 2000 rpm. Only place I saw water was a tiny drip coming from the riser plate . In the middle of the back side where the nuts are instead of bolts. Still milky under the valve cover but not as bad and I didn’t have any bolts in it . No milk on dipstick.
I can send a video running to show you but it won’t load. Thanks for replying. Looks like I’m going to be pulling the riser again

 

[kd4pbs]

Ouch! I'm sorry to hear this. Hopefully the milkiness is from moisture in the oil that wasn't removed before replacement of the head.

 

[Flashcardsgo]

Ouch! I'm sorry to hear this. Hopefully the milkiness is from moisture in the oil that wasn't removed before replacement of the head.

Yeah I couldn’t get all the old out. I’m going to drain it and refill it with good oil. Adjust the valves and see how she does.

 

[Flashcardsgo]

I was able to take the riser off and make another gasket with a better material and it went together much easier. Haven’t started it yet because when it was running before I guess the alternator bracket wasnt tight enough & it broke the belt. I have another belt but having hard time finding anything about how to put it back on. I think it looks like the front motor mount has to come loose or something to get it in there . Does anyone have info on replacing it and a belt diagram or where to find instructions. Thanks. Tom

 

[Scott Danforth]

yes, the front motor mount must come off on a 3.0, then the drive gets aligned again

 

[Grub54891]

On my 3.0 mercruiser, all you have to do is remove the two bolts on the right side of the front mount, when looking at the motor. There is a piece that comes out so belt can be installed easily.

 

[Flashcardsgo]

On my 3.0 mercruiser, all you have to do is remove the two bolts on the right side of the front mount, when looking at the motor. There is a piece that comes out so belt can be installed easily.

I saw a video on that but on mine of course the bolts are too long and hit the engine box so you can’t get that piece out ! I’m so over this engine lol.

 

[Flashcardsgo]

yes, the front motor mount must come off on a 3.0, then the drive gets aligned again

So I have to lift the front of motor up with hoist and slide belt under the mount ? Do I have to loosen rear ones too? Or just put wood block or something under the front I’m confused. Thanks.
H

 

[Scott Danforth]

not sure on your yamaha, however on OMC, Mercruiser and Volvo, slightly raise the front of the motor slightly and REMOVE the front mount. replace the belt. many people will zip tie a replacment belt to the front mount.

replace the front mount and then check alignment

 

[Flashcardsgo]

not sure on your yamaha, however on OMC, Mercruiser and Volvo, slightly raise the front of the motor slightly and REMOVE the front mount. replace the belt. many people will zip tie a replacment belt to the front mount.

replace the front mount and then check alignment

Ok. So to be sure. Your saying take the center bolt in the mount loose or out and slightly raise the motor then Slide belt behind the mount or under mount. I don’t have to raise it high enough to get the side plate off to slide belt in like a mercruiser 3.0. ? That would be raising it like 5 or 6 inches. Thanks I’m so over this job lol.

 

[Scott Danforth]

based on the pic, you should just need to take the spacer out in the foreground.

 

[Flashcardsgo]

not sure on your yamaha, however on OMC, Mercruiser and Volvo, slightly raise the front of the motor slightly and REMOVE the front mount. replace the belt. many people will zip tie a replacment belt to the front mount.

replace the front mount and then check alignment

Scott. Thanks for replying Hand grenade or gasoline seems easier at this point but I’m going to attempt it since I’ve come this far. What do you mean by the alignment and I don’t need to remove any other parts only the front center mount

 

[Flashcardsgo]

based on the pic, you should just need to take the spacer out in the foreground.

You mean the block that is in front of alternator or the round top of the motor mount. In the mercruiser version I watched that block comes off and you can put belt in there but on mine the bolts are so long they won’t come out and to get them out I would probably have to raise engine in front up like 5 or six inches which seems like you couldn’t do without breaking something in the rear.
Sorry to ask so many questions. Just seems unbelievably difficult to have to do all that to put a dang belt on. No wonder people hate this motor lol. Thanks again.

 

[Grub54891]

What’s behind the engine bay panel? I’m part redneck, I would get in there with an angle drill or the like and drill a couple of holes in the bulkhead, being careful to not drill into a fuel tank or something. Then the bolts will come out far enough. You can re-seal the hole with a plate.
thats only if there is nothing to hit on the other side.