1992 200 XRI Video - Bad bearings?

[wakepics]

My 92 200 XRI has never idled "nicely", but since I put it in the water this year I've noticed a prominent knock to go along with a jumpy vibration at idle. The motor usually takes a couple key turns to start, usually having to advance throttle a bit to get it to fire, then had sloppy idle but ran great at higher speeds. I haven't had time to really investigate this knock noise as it's been a very busy year, but I know the lower check valve in the bleed system isn't acting as a check valve anymore, so I don't think the upper bearing has been properly lubricated (for who knows how long). Would this knock accompany a bearing issue, or does it sound more like a cylinder issue? Not sure if you can tell by sound alone. Here is a short video of startup and idle. Does anyone have input on this? I'm guessing if it's bearing I'm into a rebuild, in which case I have to wonder if it's worth repowering instead :confused:


https://www.youtube.com/watch?v=XljTCGQwWoI

[nitro_rat]

That noise could be a bearing. Maybe you can pull the cowl and “sniff” around with a long screwdriver while it’s running. Just be careful of the spinning flywheel...

That’s a good old motor, would be worth fixing in my opinion. Used parts are cheap and plentiful, replacement parts are readily available (except maybe the TPS, but Brucato can solve that problem)!

[wakepics]

Thanks for the quick reply. I tried the screwdriver on the weekend. The noise is definitely coming from the upper area of the motor, but it was hard to pinpoint. I have a stethoscope I may try to use this upcoming weekend, although I'm not sure that will help. Any other suggestions to help try and diagnose this would be helpful. I should note the thing currently runs extremely rich at idle, and a fresh set of plugs this spring had 5/6 insulator tips/nose cracked within 15 minutes of run time. I think I may be dealing with a few issues, which is part of my concern when it comes to the rebuild idea.

[eli]

If plug insulator tips are cracked its time to remove power head and have a look

[nitro_rat]

If plug insulator tips are cracked its time to remove power head and have a look

:iagree:

Go ahead and pull it and see what’s going on...

[wakepics]

Well, I didn't get around to pulling the head. I checked the flywheel for play and didn't notice any. Flywheel nut may have been slightly loose but I cranked it down. The motor was sucking gas back and running super rich, so I took apart the front of it to see if I could find the reason it's burning so much fuel. My injector O-rings were worn, so I think it was flooding from that. I know I need to get the injectors serviced, but for now I put new o-rings I had lying around on. I also changed out the filters, as the injector filters as well as the fuel filter with the schraeder attachment on it had very fine metallic shavings in them.

While I had the front of the motor apart I double checked the bleed system check valve that feeds the upper bearing and now it seems to be performing as it should.

Having said that, A) The only thing I can see metal shavings coming from would be the high pressure pump. Has anyone heard of this happening, and should I replace the pump? I have a fuel pressure gauge, but I lost the adapter to connect it to the motor, so I'm going to pick one up and test pressure next weekend. Regardless, if it's sending metal flakes into the fuel system I imagine it should go anyways?

B) Would having a faulty high pressure pump along with leaky o rings and possibly stuck injectors cause the motor to idle like it does? I took it out for a spin after buttoning it back up and it did run better, but still not as well as it should. I should also note that I swapped plugs and so far no cracks on the insulators, which is making me a bit confused.:confused:

If none of this really makes sense let me know and I'll try to clear things up a bit. I think I may be getting to the point where it needs to be checked out by a professional, I just hate to have to pay someone to throw parts at it and guess as to what the issue could be (I'm good enough at that already!) :rolleyes:

[wakepics]

Ok, to continue the saga.....

Played with motor some more yesterday and this morning. Rebuilt the pulse pump as I had the gaskets lying around and I figured what the heck. Also redid timing, link and sync and TPS. Motor isn't crazy rich at startup now but I noticed it's dripping fuel/oil mix from above the exhaust port. There is visible accumulation on the back of the motor leg, and when running there is excess oil/smoke coming out of the prop area. Another thing I noted was an accumulation of water inside the cowl. I'm running the boat on a lift so the motor isn't getting swamped at all.

Now, with this information, it seems to me like I have a bad exhaust gasket under the powerhead? If this were the case it could explain the poor running condition and the "knocking" sound, correct?

I just want to make sure this sounds like I'm on the right track before I go ahead and order parts and yank the powerhead.

[Merc 2.5]

Water inside cowl. Could be a leaking water hose, leaking poppit,or exhaust divider , run it with cowl off and look for leaks 1st

[wakepics]

With cowl off no noticeable drips anywhere. It accumulates around the gasket at the base of the powered on the starboard side, so I assume it's coming through the gasket there.