300XS help

[MarylandMark]

300XS w/fleetmaster 1.75 gearcases with water intakes on bullet and side of gearcase.

50 hours port lower blew (magic throttle arm faulted for sake of conversation)
100 hours starboard powerhead- rod shot thru block on #2
120 hours starboard lower unit blew

H20 PSI- Wondering what specs are and what others are running?

I think it is under 10PSI bad, 12-15PSI best, over 25PSI bad?

I'm in the 11-13PSI range when running- little low I think but engine temps good.

Starboard engine temp is running 15 degrees higher than the port and has twice the water pressure. 115-135 average engine temp. I had impellers changed 20 hours ago. I'll check to see if the starboard was changed again when lower replaced last week; still same temp and PSI difference.

I had my gear oil changed after 20 hours and it was mud but no metal so thinking heat issue?

[Geronimo36]

I had my gear oil changed after 20 hours and it was mud but no metal so thinking heat issue?

Mud????? Like grey color??? If so I'd guess the lower gears coming apart or bearing failure. How about black? that's heat... Does the oil smell to high heaven when you drained it?

My experience has been the lowers on the mercs are notorious for blowing on the bigger engines and especially cats.. They don't like barking between waves due to the clutch dog design. The lowers are basically the bottom half of an Alpha 1.

Yamaha has the right idea on the 350's by beefing up the lowers.

sorry I can't add much more info... AS for the water pressure and temps... might be the poppet valves.

[MarylandMark]

My mechanic told me it looked like mud; I never saw what it actually looked or smelled like or what color it was. I told him I've heard to change the gear lube often- going to have it changed in like 15 hours to see what's up with it.

I learned my lesson on the barking on the 1st lower. I changed my props and motor height the night before the Jammin on the James 08 and barked at every one before going BOOM. I shattered the clutch dog like I slammed it in gear at 5K RPM.

The starboard lower spun a bearing which locked up or whatever they do and that is how it blew this last time.

[MOBILEMERCMAN]

If the water pressure has gone up with out any changes in set up I would suggest a compression test. When the cylinder pressure leaks it raises water pressure.

As the barking goes. Keep count they tend to fail around the tenth time.

It might be cheaper in the long run to get a race boat to dog and cruise in your CC.

[PayCheck]

Still under warranty?

[MarylandMark]

Still under warranty?

Yep- til 3/5/11

[PayCheck]

So you're planning another banner season...nice rhythm

A 50 hrs blewey
A 100 hours kaBoom
A 120 hours blewey
A 1xx hours_______. You fill in the blanks

[Geronimo36]

As the barking goes. Keep count they tend to fail around the tenth time.

Dude, I'll never forget how many lowers Ron went thru on those Bridgeports!!! Not sure what was worse though...the lowers or the powerheads but I think the lowers take the cake..

I'll also never forget the starting them in-gear like it was a crash box!!

By the way, has merc made any enhancements to the lowers since then?

[Geronimo36]

The starboard lower spun a bearing which locked up or whatever they do and that is how it blew this last time.

I've seen them loose the vertical shaft bearings (probably the mud you had), then it messes up the gear lash and vibrates.. Next step is the pinion throwing a tooth out the side of the case (like throwing a baby out with the bathwater) and locking up!

[Geronimo36]

Yep- til 3/5/11

Be careful bro, I'd back off on the sticks.. When the warranty runs out you're going to be left with some tired equipment.

Unless you plan on getting a new one.

[MarylandMark]

I'm trying to keep this stuff nice so it works when it's out of my pocket but some how that plan has not worked out too well.

My mechanic went on vacation (the nerve- sounds like he is making too much money!) but when he gets back I'm going to have him check the specs and more than likely will be lower the motors a notch to see how that goes. I raised them a notch on my quest for speed. The boat did seem to run better but with E10 fuel it feels like I've lost some get-up-and-go so going to drop them back down to see what happens.

Unless you plan on getting a new one.

-my marina says they are going to dredge (been hearing that for a while but this last year they had the actual gear there)
-I'll be married by then so that is 1 step out of the way (don't have to be on my best behavior any more right?)
-$$ been on hold until I was in a house but is happening in less than a month-
-was waiting on a new RV until the house was done and waiting on a new boat until the RV was done

[MOBILEMERCMAN]

Dude, I'll never forget how many lowers Ron went thru on those Bridgeports!!! Not sure what was worse though...the lowers or the powerheads but I think the lowers take the cake..

I'll also never forget the starting them in-gear like it was a crash box!!

By the way, has merc made any enhancements to the lowers since then?

They 2.5 lowers are basically the same.

He would start it in gear when they wouldn't idle. I came up one time he was complaining the center wouldn't idle. I checked it out and found a hole in the block like a mail slot.You could see right through it. It had been running on 5 cylinders for a couple weekends before he called.

[Davidmnc]

They 2.5 lowers are basically the same.

He would start it in gear when they wouldn't idle. I came up one time he was complaining the center wouldn't idle. I checked it out and found a hole in the block like a mail slot.You could see right through it. It had been running on 5 cylinders for a couple weekends before he called.

How do you not notice that?

[Geronimo36]

They 2.5 lowers are basically the same.

He would start it in gear when they wouldn't idle. I came up one time he was complaining the center wouldn't idle. I checked it out and found a hole in the block like a mail slot.You could see right through it. It had been running on 5 cylinders for a couple weekends before he called.

How do you not notice that?

I kinda felt bad for him, still do. He just had no idea I think...

One time his little Apache sunk in the "rack" Yeah, in the rack...and he pumped all the fuel/oil out into a 55 gallon drum and left it in the yard, just left it there!! LOL

Another time when he blew up the stroker motor in the Apache we had the busted cylinder head on the bench and my buddy Billy walked up behind us as we were looking at it in amazement having a huge hole and pieces of the valve and spark-plug embedded and Billy said; "Can you weld that?" Oh man we had a good laugh!!!

[MOBILEMERCMAN]

How do you not notice that?

3 noisy motors.