Exhaust Restriction Further Update

[FreeBeeTony]

I know alot of you have been waiting to hear about my progress.<br /><br />Well, picked up the trailer yesterday and hauled the boat out of the water today.<br /><br />Pulled the outdrive hoping to see something like bondo posted. I didn't see an exhaust flapper, but I did see what appeared to be a bolt. All the way in the back looking into the exhaust passage from the transom. I can't see it to well, even with a drop light. The bolt was vertical. I was able to reach it with a couple of long 3/8" extensions. It's not loose, I couldn't move it. From what I have seen looking at figures of the y-pipes, this bolt shouldn't be there. Or is is supposed to be there? <br /><br />How does the y-pipe mount to the transom plate? I thought it was 2 or 3 bolts going into the transom plate. If that's the case I shouldn't be seeing what I am seeing.<br /><br />I removed the rubber boots and elbow between the risers and y-pipe and ran a garden hose through. As my son applied the water, I watched from the outside. The water seemed to come out of the holes on the sides of the gimbal housing, rather than the main exhaust passage.<br /><br />Had to walk away from it for today........

 

[Don S]

Re: Exhaust Restriction Further Update

Look inside the drive also for the flapper, it doesn't have to be in the Y pipe.<br />Not sure what that bolt is. There is nothing bolted to the pipe like that, so it shouldn't be there. There are 4 mouning bolts that hold the Y pipe to the transom shield, but you can't see them from inside the y pipe.

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

Hi Don, the outdrive seemed clear. I didn't seperate it though. Can i turn it upside down to see if somethiong is loose in the exhaust passage?<br /><br />What about where the water is coming out? Is that normal?<br /><br />How hard should I pull on this bolt in there? Should I give it a light tap with a hammer and the extension bar?

 

[Don S]

Re: Exhaust Restriction Further Update

The holes where the water is coming out is the idle reliefs, and it's normal when out of the water. In the water it takes the back pressure off the engine at idle.<br /><br />There isn't supposed to be any bolt in the Y pipe. So what ever is there is probably your problem. I can't see what, where, or why it's there, so can't give any information on how to remove it, except to say it probably came from the inside out. So if you pull the riser and elbow on that side, maybe you can make a hook and see if you can fish it and what ever it's attached to out of there.<br /><br />Yes, you can turn the drive upside down and check. Also pull the prop and look inside the cavity.

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

Prop is already removed.<br /><br />I was going to try and take a pic of it but don't think it will do any good.<br /><br />What about giving it a tap like I said?<br /><br />I don't want to break anything.<br /><br />Don't want to pull the engine until the fall/spring........think I may have an oil leak (rear main seal?).<br /><br />Will try again tomorrow..........thanks for the help. Was hoping this would be easier.

 

[Don S]

Re: Exhaust Restriction Further Update

Was hoping this would be easier.<br />

It's a boat, why would you think it would be easier? <br /><br />Give it a tap, not a hard bang, if it breaks with just a tap, then it was dead anyway. Those exhaust Y's are a lot stronger than that, they are cast aluminum, aluminaum, aluminiam????? aluminam???? hmmmmm you know, that light weight metal, and should take even moderate hits without any damage. But that bolt shouldn't be there.

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

Any hints on getting it out from the outside?<br /><br />Can the rod for the shift lever be renoved to provide any additional access?

 

[Don S]

Re: Exhaust Restriction Further Update

Remove the exhaust bellows from the transom shield and lift the bellhousing and see if some long needlenose pliars will get it.<br />I can't see it, and neither can anyone else, so it's impossible to say what it's going to take to remove it. Don't even know what it is, or where it came from.<br />Did you look from the inside or try to reach it with a hook of some kind?

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

Thanks Don..........I will try again tomorrow.<br /><br />How difficult are the bellows to remove and replace? Have not fooled with bellows yet...... <br /><br />Also, the bolt is right in the center of the opening. I don't know if that means anything.

 

[Don S]

Re: Exhaust Restriction Further Update

NEED picture!

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

I will try to post a pic tomorrow, but I don't know if it will be able to show the bolt.<br /><br />I would like to see a pic of a y-pipe from the back side showing the flange. In the manual they show a diagram of the transom plate where the y-pipe gets installed. Looks like 2 openings, 1 on each side. Is this where the water goes that comes out the idle passages? I also shot water into these passages.........

 

[rbezdon]

Re: Exhaust Restriction Further Update

Hey Tony, it may seem like a pain now but at least you found something that could explain and possibly fix your problem!!! That is the good news side of this. I fixed my bog and finally got the sift adjusted and every thing working and bang, I broke something inside the engine so now back to the drawing board (or should I say garage to pull apart that motor again). Good luck and look forward to the pic of your unusual situation.

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

After further investigation what I thought was a bolt is just the cebter of the y-pipe. It looks like the inside of the pipe comes to a point, that's what I thought was a bolt.<br /><br />Can someone confirm what the inside of the pipe looks like? I can't take a pic, can barely see it to begin with.<br /><br />If this is the case, now what?<br />Can I have a bad cam like vatter?<br /><br />Really could use more help now.

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

Just got done confirming my own suspicions.<br />With the aid of a good flashlight and wire hanger, I confirmed that what I thought was a bolt was the inside of the pipe.<br /><br />I was able to snake the hanger down both sides of the pipe and up the exhaust cavity in the outdrive.<br /><br />Now what?<br /><br />I am leaning towards putting the boat back in the water and finishing out the season like it is...unless someone else has another idea.<br /><br />Then I have to figure out how I can pull the engine in the fall. I don't really have anywhere to work on it......

 

[Buttanic]

Re: Exhaust Restriction Further Update

All I can say without being able to check it myself is I still think you have a fuel related problem.

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

Could it be the cam?<br /><br />What other tests can I perform?<br /><br />Should I try to measure the cam lift?<br /><br />I don't even know if I have roller lifters or not.

 

[FreeBeeTony]

Re: Exhaust Restriction Further Update

What is the difference in weight between a SBC and an IL6, including pistons and crank, w/o manifolds and heads.<br /><br />Then I will see if I can get the block into my basement like I did with the IL6. I slid it down the steps with a heavy duty hand truck. Did most of the rebuild downstaris and the final assembly in the boat.

 

[Don S]

Re: Exhaust Restriction Further Update

Since you have the drive off, look on the port side of the upper and see what it says for the gear ratio. Also put the drive in forward and turn the prop shaft till the dogs catch. Mark where the porp is, and where the ujoints are in relation to the drive, now turn the ujoint shaft in the direction of engine rotation till the prop turns 360°. How many turns of the ujoint shaft did it take...... be exact as possible.<br /><br />At this point I see no reason to pull the engine, did you measure the up and down motion of the push rods? That will tell you if the cam is ok or not. You don't even need to know what they are supposed to be. Just measure the movement of the intake valves, then go to the exhaust valves. All intakes should be the same, all exhaust should be the same..... Doesn't mean anything rather you have roller lifters or not.

 

[Boomyal]

Re: Exhaust Restriction Further Update

I would estimate the weight of a SBC fully dressed with intake, flywheel, waterpump, etc at about 550 lbs

 

[rbezdon]

Re: Exhaust Restriction Further Update

Tony, I doubt you have a cam issue. I told you, I think my problem was actually the way the carb was mounted. I was told the spacer lowered the signals to the carb and I think it was too much. I changed the cam AND remounted the carb at the same time so there is no way to know for sure but I am pretty certain. Also, my replacement engine came from a place that does automotive and marine, some chance for a mix up. Your cam is the same one been in there since the factory built it, not likely it is wrong. And like Don says, don't pull the engine if you dont have to. You're sure not going to do the machining for a rebuild in the basement. You are going to send out the block and heads for machining or buy a remanufactured engine for that. The engine assembly all could be done in the boat. Put the crank, timing chain and cover on and oil pan and put the block back in and do the rest in the boat. I am pulling the heads so the whole top half in the boat no problem, but only IF you need to. Sure seems like fuel or something easy must be your problem.