Lower unit?

[Okiefish70]

I have a 2000 mercury 200 EFI, 0T100528 that has developed a "clunk" in the motor/lower unit, I got it out for the first time last weekend and I noticed when I put it in gear and was idling out it would make a kind of clunk sound every three or four seconds but would stop after a minute and when I got it up on plane no problems or weird noises. I tried to rev up to get on plane once before it was still doing its clunking thing and it sounded like it had half slipped out of gear and like the teeth were not engaging on the shaft. Im not sure whats going on, any thoughts?

[Savage]

I would start by checking the prop hub first, because its simple and easy to do, then go after the harder items.

[JOE54]

^^^+1 check for metal debri in gear oil also may need a bit pf cable adjustment , how does it act in reverse under load

[EuropeanAM]

^^^+1 check for metal debri in gear oil also may need a bit pf cable adjustment , how does it act in reverse under load

^^^^^ This.

And most important: DO NOT attempt to accelerate fast like that again until it's been resolved. That noise you heard was metal grinding away from the clutch dog and forward gear.

[JOE54]

^^^^^+1

[Okiefish70]

It seemed that once the clunk happened 4 or 5 times it would quit (by the time I got to the buoys) and I could throttle up and get on plane with no problems or anything making any weird noise. Just a bit of useful information....I did replace the water pump a couple days before taking the boat out for its first time this season, also I removed the prop to get a wad of fishing line from behind there but I made sure to re-install everything correctly...also this clunk was happening last year but only once every other time I would crank up to move to a different spot I noticed that sometimes as I was idling through a cove that it would do this but really not very often in the course of a day.

[JOE54]

see any water in gear oil ???

[leonreno]

Could be it’s not the lower unit and you may have a loose exhaust tuner in the midsection, does motor seem a little louder?

[Okiefish70]

After viewing several videos on <Announcements> I learned how a lower unit operates and what a clutch dog is...I believe that after 24 years my clutch and forward gear may be worn down enough to start having problems, to my knowledge this lower unit has never been rebuilt...I did however adjust my shift linkage approx 1/4 inch to hopefully get a little more travel out of the shift shaft and maybe get the clutch dog to mate up with the forward gear a little better.

[Okiefish70]

prop hub looked good, no signs of excessive wear or tear.

[JOE54]

report back with results of adjustment

[Okiefish70]

I was able to get the boat to the lake yesterday after work to test the adjustment that I had made to the shift linkage, I had success it seems... the lower unit shifted into forward and I was able to idle and throttle up with no clunks or noise or problems at all...it felt good again, solid. Im hoping this gives me a bit more time before I have to commit to a rebuild situation. First tournament of the season is this weekend so that will be the true test, thanks for the suggestions folks, tight lines!

[JOE54]

nice

[Okiefish70]

The boat did really good this last weekend, it was very windy so I had to keep it on top of the waves, no problems whatsoever. On a side note (and to answer a previous question) when I changed out the gear lube much to my surprise there were no metal flakes or chunks in there! I would have really thought there would be some flakes at least but other than being black used gear oil it all looked fine. I used what was left of a quart of quicksilver and finished it off with supertech 90 weight marine gear lube, the quicksilver is a dark blue color and the other was amber, I havent heard anything about not being able to mix two different brands.

[EuropeanAM]

If it was High Performance Lube, don't mix it with other lubes. I personally don't recommend anything other than the High Performance lube for that gearcase (unless you're going to but the Racing lube). Don't mix those two, either.