Pro 50 oil pump issues, among other things.

[Pat Gidley]

I cant seem to figure out why my oil tank is continually leaking when the motor is tilted up.

So...this week I got to thinking I'd sort out that leak and re-install the oil injection. Put a new O-ring in the Keihin pump and it all seemed rosy, oil pump pumping away and working effectively. Until this morning, oil leaking out of the cowling again! I think it's leaking from the cap.

[bajakeith]

yamaha outboards

the best answer to your problem is to buy a mercury....LOL

[Pat Gidley]

Ha ha ha. I've had great luck with my Evinrude 9.9.

Well I just tracked down a Mikuni pump on ebay and bought some check valves. I'll give it a go.

Another question - can I use snowmobile fuel and primer line in place of the oil lines? I have a ton of it around and it seems to be the right diameter.

[bajakeith]

HI Pat !!

was the bearing that made a lean condition the top or bottom bearing ?? if the bottom how did you find it ??

[Pat Gidley]

It was the bottom bearing. I had replaced the gasket with no results, so checked the top bearing thinking it was that. When that one looked fine, figured might as well check the bottom one. The weird thing is it felt fine and showed no visible signs of wear, but when I pulled it, it was all beat up on the underside. I suspect the previous owner couldn't figure it out, which is how I ended up with the boat (for a really good price )

[99yam40]

Another question - can I use snowmobile fuel and primer line in place of the oil lines? I have a ton of it around and it seems to be the right diameter.

Not sure what those lines for a snow machines are made of since it does not snow down here much.
But if good for the gas we have now a days I would think it would work OK

[99yam40]

It was the bottom bearing. I had replaced the gasket with no results, so checked the top bearing thinking it was that. When that one looked fine, figured might as well check the bottom one. The weird thing is it felt fine and showed no visible signs of wear, but when I pulled it, it was all beat up on the underside. I suspect the previous owner couldn't figure it out, which is how I ended up with the boat (for a really good price )

I thought my C40TLRX had a bad bottom bearing( rumbling a little)
When I pulled the crank, 3 out of the 4 were rough . Top one was the only good one.
had to send it off to have it redone.

Saw a small amount of rust on crank.
Water will get the crank bearings as will no oil, but in no oil I would think the rod bearings would have shown it not just the crank ones

[Pat Gidley]

The nice thing with the snowmobile fuel line is its transparent, so I can be sure theres oil in there, and holds up pretty well in the cold so its nice and flexible. No point in buying new lines when I have piles of that stuff around.

I was lucky with that crankshaft bearing - there were a few scuffs on the pistons, but nothing too alarming and it runs with good compression now. Just gotta work out these other little gremlins.

I think I can figure out the hose routing for the Mikuni, but I read a few mentions of a diagram kicking around. If anyone has it, could you email it to me? Let me know and I'll send you my email addy. Or even a pic of any 3-cylinder with the Mikuni pump will be a help. Mostly need to figure out the extra line going back to the oil tank, thats hard to see in the diagrams.

[bajakeith]

HI Pat

Congrats on finding the problem....the top is easy to ck..bottom is not..BUT,,, was the bad bearing a combo bearing/seal (one piece) or a seal below the bearing..( long day in the bilge and too lazy to look up)...PS,, Don't use any fuel line that is not marine rated !! somewhere will have a CG cert number..... very,,very important...

[zenoahphobic]

If it is clear probably will go hard with time. If it yellow it may be Tygon and that should be fine. Nice to see inside lines for various good reasons!

[Pat Gidley]

Hmm the stuff I have is blue. It goes brittle after 3-4 years. I'll try it out and swap out for the OE stuff once I can verify that everything is working.

I pulled the thermostat last night and cleaned it up, hopefully it was just stuck or something. Didn't overheat on the garden hose water, but I'll take it for a boot on the lake tomorrow and see if that problem is cleared up.