Yearly maintenance, and switching to synthetic
 

I bought this boat last year. 1993 454 magnum (carbed 365hp) bravo one in a formula. Drained the block and winterized it last fall, but didn't change any fluids.

I'm planning to change the oil before we put it in the water, and considering the switch to synthetic. The boat has lowish hours (around 375), but it is a 1993, so it isn't like it is a "newer" engine. Would any recommend against the switch?

Also, is it standard procedure to change the fluid in the outdirve every year?

I've heard some say they put in a new pump impeller in every year as well... necessary?

Thanks,
Scott

All those things are the cheap things you can do to prevent expensive bad things from happening. So yes, I do mine every year. I live in a pretty clean lake so I have skipped impeller before for a year but it's still not a great idea.

I haven't done it but I've certainly heard of people changing to synthetic and causing leaks. I might be inclined just to keep running whatever they have been using.

I change engine and outdrive oil as well as seawater/fuel pump oil every 20 hours. Change oil/outdrive oil prior to winterization to get rid contaminants/water in oil. Impellers every other year.

Change Drive lube once a season or 50 hrs.
Switching to synthetic oil will be fine and there are no negatives. I prefer Mobil 1 15w-50. Walmart for about $26 for a 5 qt jug.

Being that those are flat tappet cammed engines, I'd run an oil that has a good amount of zinc in it. Diesel oils used to, but I read they have pulled some of the zinc out as of recent.

^^^Bingo^^^

I'm not a mechanic - but this is my two cents

1. I would keep the same oil that has been in the engine since day 1-- Synthetics in my opinion are the best out there - Especially Mobil 1. But if you are doing well with the current oil there is no need to change nor will it offer any significant benefit. I've heard the rumors of leaks with switching to synthetics - personally I think that is a bunch of bunk - but again I'm not a mechanic.

2. I change drive oil every year - engine alignment check every other year.

3. The impeller is dependent where you boat. In my experience I changed the impeller after 2 years and with about 150 hours run time - it looked as good as new. My intention is to change in in about 4 years. -- but again that is where I boat - very little if any silt or sand.

All the best

3pointstar

Synthetic, synthetic, synthetic... Mobil 1 15w50. Zinc is not an issue with Mobil 1. Even calls out "for use with flat tappet cams".
https://mobiloil.com/~/media/amer/us...pecs-guide.pdf

Yep M1 15w50 is hard to beat. Currently $22 for 5qt jugs at Walmart with a $12 mail in rebate till 5/31.

My two cents.
I change engine every 25 drive every 50. But when I stored over the winter I would change at the end of every season so it sits with nice clean oil in both.

As for the impeller, I would do them every spring because my thought is the rubber has been in one position the whole winter. It's not like they are expensive.

I did engine and drive every season and impellers every other.

impeller every year? every 2 or 4 years? you have no idea how many years on that impeller. replace it. pull hose on inside of transom. backflush coolers from pump back to transom. put another hose on transom. backflush from there out to the water pickup(s). NOW you can worry about oil. and belts too...

Thanks for the feedback gents.

The previous owner had a local shop do all the winterizing and de-winterizing every year, and they put in a new pump and impeller last spring. I'm not opposed to dropping a new one in.... Is this something I can order from amazon?

This kit here: https://www.amazon.com/Impeller-Serv.../dp/B0077RKSJM
??

I'm considering Mobil1 15w40, vs 15w50 as this is mostly in cool weather climate here in Montana. We do hit the mid 90s here in July/Aug, but the lake water is rarely much above 60. 50 weight oil just seems kinda heavy??? ...my mind isn't made up yet, just asking the question.

It looks like I have this:
https://www.walmart.com/ip/Mobil-1-1...354#about-item

Or this as an option:
https://www.walmart.com/ip/Mobil-1-1...5-qt./20713647

I believe this has the high performance quick silver or mercury equivalent gear oil in the LU, I think I'll go with that. I'll get ready to cut an arm or a leg off for that one.

Now I just need to figure out what to run as a filter. I'm hoping to pick up everything today so I can get it done tomorrow.

Is purpose here is to clear out an gunk that may have made it's way into the coolers, or the stern drive pickup?

Yep. If i winterize my boat I backflush everything just for kicks, and it's especially a good idea on an known boat so if a problem develops you've eleminated some possibilities.

I also rarely get to go full tilt and stay with the 40 weights. No problems so far. If I do get to run wide open for a while it'll drop to 25 or so at idle then quickly regroup back up. If you don't see it regroup after some running hard then you can try the thicker stuff.

There is also nothing wrong with 25 at idle. And I hear full synthetic has a film strength much higher than, well, oil-based oils.

So you're saying if you do a lot of WOT operating, you'd want thicker oil??

Sorry, I didn't want to turn this into an oil thread :). I live on a pretty big lake, one of the spots we go to often is about 20 miles of boating, so if the water is decent we just drop the hammer and get there, running 30 min straight sometimes, so, perhaps I'll go with the15w50.

Get the Mobil 1 15w-50. It is the older and better formula.

So I got all the plugs back in, tightened it all up and gave it a test start to make sure everything was okay before i started changing fluids. My partner was supposed to be watching water flow. Well he didn't take notice that the ears slipped off of the pickup.... i noticed engine temp start to climb and shut it down. Didn't take long, the impeller WAS working, it isn't now.

So, I guess I'm replacing it :). The impeller with some other parts (some sort of back plate) is about $70. The shop wanted to 2 hours labor to do it themselves, and they're charging $130 an hour, so I'll be doing this myself. This cant take 2 hours to replace!!??

If your a big guy like many of us and your engine compartment is very cramped, it can take you 2 hrs just to get yourself back out of the bilge. :eek::lolhit:

HA, well I did experience that with the drain plugs, I felt like I had to do a handstand to get those things in and out. The accessories on this are fairly easy to reach though, shouldn't be too bad.

One of the local dealers had an impeller kit, hopefully the housing is in decent shape. The guy at the parts counter told me I could just lubricate it with dish soap when I installed it.... does that sound right?

Yes

If the impellar is missing pieces you need to go find them. Typical places are in the inlet to the coolers. ie:stuck in frt of the small tubes.

When you change your oil for seasonal layup, make sure you start and run the engine for a bit.

If you don't the only part of the engine that receives the benefits of new oil is the pan.

Ken

OIl every year(VR1), impeller every 5 or more. One lasted over 20 yrs and 2000 hours..They are not as wimpy as most think.

^^^^Yup, have a few boats here that are on original impellars. One's a 1994 and the other I believe is a 1990 ? Known the boats since new. I ask every spring and I keep getting the old 'temp is fine, don't worry about' answer. LOL.

My 3 boats get new impellers every 2 years. I have a box of "like new" impellers for all 3. Just in case I ever need one...

I use Mercruiser semi syn 25W-40 in the 4 cycle engines changed 25 hrs for the 525s and 50 hrs for the 350 mag. Mercury Premium Plus semi syn outboard oil in the 2 cycles. No oil problem. Ever.

Mercury High Performance gear lube in all 5 outdrives annually.

Hours range from 270 to 340 on the inboards and 500 on the outboards. No service issues on engines or outdrives.

Well, here is what is left of my impeller:

http://i82.photobucket.com/albums/j2...pssftexqva.jpg

Go looking for more impellar parts. There will be some in the cooling system. Most definately jammed against inlet to oil coolers.

I'm not looking at the engine now, so I haven't routed water flow yet.... is there a standard sequence, such as... oil cooler, then engine, then exhaust housings... or does it split and send water to multiple locations. I think i'm going to rig up some hose connections to flush lines back towards the pump, and just work back from each choke point.

Well I found some diagrams... water flow seems to go like so:

raw water pump -> oil cooler -> PS pump cooler -> thermostat housing -> then engine (if T-stat open) & exhaust risers (always flowing)

Can I assume that no impeller bits of significance would have made through the oil cooler? As in, if they made it that far, they would pass through everything else?

Or add a zinc additive, they're commonly available I've found.

Neither of my manuals state to check engine alingment. What is the benefit? Why would it move?

Get a flush kit installed in the raw water pick up hose and you can do it yourself with out fluffs!!

This engine only appears to have one oil cooler, so I'm going to assume that there is only an engine oil cooler, and no PS fluid cooler. I'm rigging up some fittings to flush back from the thermostat housing through the oil cooler and out the outlet hose for the raw water pump. I can't imagine that won't get the bits out with the pressure from a water hose. Should I also look for bits in the Tstat housing?

Is there any benefit or point to pressure flushing the manifolds out through the exhaust?

Just back flushing through the oil cooler will most likely NOT get the pieces out. They stick into the oil cooler tubes pretty hard. Do yourself a favor and just pull off the cooler and push the pieces out with a piece of stiff wire. Also, don't waste your time putting a new impeller in that old housing. get the whole kit with the new housing. I always put a piece of gorilla tape on the cups of the muffs to keep them in place.

I was afraid someone would say that. Yup, already got a complete kit with housing, this one was in pretty rough shape.

Well I backflushed this thing as a first pass, it seems to flow water fine, and there doesn't seem to be any built up pressure in the hose prior to entering the cooler (which seems to be a combo oil/PS cooler). I imagine you have drain oil, then disconnect all oil lines, and remove entirely. This looks like a PITA. Good lesson for me I guess... take care of your damn impeller - you don't want it in parts.

Do I really need to take this thing off? I'm not sure much water flowed after this thing went. Water was actually cut off (the ear muffs slipped a few inches off), so it wasn't flowing when it turned to dust, it was simply run dry. I've got 4 veins that are about 2/3 complete. The rest was dust and small bits and most all of it just fell out of the pump housing. We did try running it again after we determined we lost water flow at the pickup, but it wasn't pumping anything by that point, so I doubt it could have move much beyond the pump.

All work done, pump fixed... running and cooling like a champ.

Thanks for all the feedback folks, I was able to get it out for memorial weekend, and we had pretty good conditions:

http://i82.photobucket.com/albums/j2...psylgd5gwj.jpg

I thought of putting a large hole screen, like chick wire sized, in the hose between the raw water pump and the oil cooler(s) or put a strainer after the raw water pump(even better).. Would catch debris well..Seems these impellers are always coming apart..

Or replace raw water pump entirely with something totally different that was not such an awful design..