1989 50 hp Wrist pin question.

[gaforce1989]

I have a 1989 Force 50 hp (507Y9B) that had a broke ring and a damaged piston. The cylinder cleaned up nicely and was within specs according to my SELOC manual. So I was just going to replace the piston/rings (Standard bore) and seal it back up. I ordered a piston from iboats thinking it was the F694015 replacement, well I received a replacement piston for 834794T3. The website states this is what has replaced F694015. The original piston wrist pin is retained with clips, the new piston has a slip fit wrist pin on both sides of the piston with no provisions for any type of clips. Im confused because I cannot find any clear answer as to whether or not this is correct or a casting flaw. Any info would be appreciated. Thanks

 

[pnwboat]

Re: 1989 50 hp Wrist pin question.

I don't know if this is the case in your scenario and I would not consider myself the "expert" in this area, but on the larger 3 and 4 cylinder motors, the only pistons that I've seen with circlips to hold the wrist pin in place are the after market forged pistons such as Wiesco and Vertex and maybe a couple of others that I can't think of. The original pistons were cast and had pressed wrist pins. To remove the factory pins, you're supposed to use a special wrist pin bearing spacer tool and a hydraulic press.

Maybe the piston that was damaged was an aftermarket one? Look closely for any names or markings possibly a part number on it. The Wiesco aftermarket piston use a different set of wrist pin bearings too.

 

[gaforce1989]

Re: 1989 50 hp Wrist pin question.

Well what me real question is. With this new piston I can take the new pin and push it straight through. Its a tight fit but I can push it through with minimal effort. and since there are no provisions for clips what exactly would keep the pin from beating the cylinder wall.

 

[pnwboat]

Re: 1989 50 hp Wrist pin question.

That's the way it should be on the piston. It gets pressed into the hole in the connecting rod. I've removed them with a 2 ton manual arbor press and it took everything I had plus a 2 foot long extension bar and heating up the connecting rod. I use a 30 ton hydraulic press now and it makes a world of difference.

 

[gaforce1989]

Re: 1989 50 hp Wrist pin question.

My rod is oversized to ride on several needle bearings with spacers on either side of the rod. If i must press my pin in the rod then this piston requires a different rod.

 

[jerryjerry05]

Re: 1989 50 hp Wrist pin question.

I believe the 89/50 needed the wrist pin pressed in.
If it just slides in and out it's the wrong one.
Is there a place for C-clips?
Send it back and get one from Wiseco.

 

[pnwboat]

Re: 1989 50 hp Wrist pin question.

I'm sorry I made a mistake. My apologies. It's been a while since I've done one. The pin is pressed through the two spacers. The spacers are what hold the pin in place. The spacers are positioned on each side of the small opening in the rod to keep the needle bearings in place. That's why you're supposed to use the special tool to keep a small gap between the spacers and the needle bearings so they roll freely. If you don't, the bearings get bound up between the two spacers.

 

[gaforce1989]

Re: 1989 50 hp Wrist pin question.

thanks pnwboat, I kind of figured the spacers are what held the pin but I wasnt sure at all. Thanks.