Hole in motor on 1984 6hp yachtwin is this suppose to be here ?

[kevinstan]

Found this while changing the fuel pump. Is this suppose to be here ? Or could this be the cause of my problems ?

 

[F_R]

Not sure, could be a defect in the casting. If it goes clear through to the inside, it surely would be a problem. But it would have been a problem from day one and there would be a large mess of fuel and oil all over everything. Since it is clean, it doesn't go through so relax and ignore it.

 

[Vic.S]

As F_R suggests it could be a casting defect. I think Id fill it with some JB Weld or similar filled epoxy


But aren't we already answering this on another thread ?

 

[kevinstan]

Yea your right Vic. I started a new thread for others to see the topic and be able to comment as well. I greatly appreciate your feedback and I have not yet tested to see if the hole goes all the way through or not, but I do want to fill with jbweld to be safe. What type of jbweld specifically should I use ? Aren't there different types ?

 

[Vic.S]

Yea your right Vic. I started a new thread for others to see the topic and be able to comment as well. I greatly appreciate your feedback and I have not yet tested to see if the hole goes all the way through or not, but I do want to fill with jbweld to be safe. What type of jbweld specifically should I use ? Aren't there different types ?

I was thinking of just the original Epoxy adhesive but Steelstik epoxy putty might be the best choice.

You'll need to be carefull if the hole does go right though. You'll not want a lump of cured epoxy in the crankcase!

 

[Scott Danforth]

I would take a photo a bit further out.

 

[kevinstan]

No Title

Here is an image of the hole with the fuel pump on.

 

[kevinstan]

No Title

Here it is backed up a little with the fuel pump off. I haven't yet tested to see if the hole goes all the way through but I will when I get home today.

 

[Scott Danforth]

just wondering out loud if there should be a hose nipple there to pressurize the one side of the fuel-pump with combustion pulses.

 

[racerone]

????????------Combustion pulses are not used to pressurize / drive the fuel pump !!!--------The hole inbetween the 2 mounting screws for the pump is used to drive the pump diaphragm with crankcase pulses.-------Put some oil in that casting flaw and if it does not disappear you are all good to go !!

 

[kevinstan]

Just regular 2 stroke oil ? I'm afraid if it does go to somewhere I don't want to be dumping oil in it. I might just patch it anyways to be on the safe side.

 

[F_R]

You aren't understanding the whole situation. IF---IF it goes through, it would be going into the crankcase. There is fuel mix (gas, oil, and air pressure pulses) in the crankcase. So if it goes through those pressure pulses would be blowing a cloud of fuel mix out through the hole. A LOT of fuel mix. Since it is dry, that simply isn't happening. Go ahead and plug it or put oil in it or whatever you want to do--or not do. Just don't go trying to poke it through. You may succeed.

 

[racerone]

I am afraid that you do not understand the level of advice you are getting.---Put some oil into that hole and see what happens !!----Sewing machine oil or 3 in 1 oil or whatever you have on hand !!!---Nothing can be hurt by doing some simple testing with oil in that apparent casting flaw !!

 

[interalian]

Here it is backed up a little with the fuel pump off. I haven't yet tested to see if the hole goes all the way through but I will when I get home today.

What I see from this picture is a casting bore that's tapped for something that bolts in from the right. Is that a bolt head with a washer at the upper right corner?

 

[Vic.S]

What I see from this picture is a casting bore that's tapped for something that bolts in from the right. Is that a bolt head with a washer at the upper right corner?

Yes you are absolutely right. I have been and looked more closely at mine.

It is one of the bolts bolting the cylinder block and crankcase together,

Just below the pin # 6 in the diagram below

Puzzle solved

No need to do anything about it!

 

[kevinstan]

I am missing something. On mine it isn't below pin #6 - or am I looking at this wrong ? So Vic, is this hole on your yachtwin as well ?

 

[interalian]

If you're up for one more picture, shoot one straight at the joint between the two halves of the crankcase with that hose/wire moved to one side. I think it is a bolt hole.

 

[racerone]

This is starting to read like a comic strip !

 

[Vic.S]

I am missing something. On mine it isn't below pin #6 - or am I looking at this wrong ? So Vic, is this hole on your yachtwin as well ?

The actual bolt is not shown on the diagram. It is one of a set of 4 of which only one is shown, for clarity, as #4
You can see the head of the bolt in your picture in post #8

Yes the hole is there on mine. Not obvious with the pump in position but it's there

 

[Vic.S]

If you're up for one more picture, shoot one straight at the joint between the two halves of the crankcase with that hose/wire moved to one side. I think it is a bolt hole.

No need.

You are right