Uh-Oh ... Check that Impeller!

[Frank C]

Who was it worried about shearing bolts?
And it was Kevin who wrote of a kindly machine shop?

Well it's still the holiday weekend, so the machine shops are closed, and here's my tale of woe. I quite successfully managed to crack open the gear case today, without any manual. Just take it nice & easy, tap w/ a 2x4 after removing the six obvious bolts. Hmmm, obviously still quite attached. Figured that I should remove the anode and sure enuf, a seventh bolt! After removing that one the lower gear case separated nicely.

So, there's the water pump ... so far so good! Just four bolts, replace impeller & gasket, smear a thin coating of silicone, & back under way. But NOOOOO! The first of those four bolts shears nicely into the socket.

HMMM. Well let's try to be more careful .... next bolt turns with great difficulty, but at least it turns.

The case is clearly a machined aluminum casting. Not sure what the bolts are - could they be aluminum too? Anyhow, the third bolt shears off too. Guess I'll need to toss this puppy in the back of pickup & find a machine shop on Tuesday. But the thing that's most worrisome ... how is an easyOut ever gonna back out those studs?


WORDs-to-the-WISE (upon edit, 2 days later):
Nobody wants to work on a $1,000 casting w/ sheared bolts .... hmmm, wonder why??? The local Merc dealer says he could easily spend 6 hours (about $500), yet still end up ruining the casting. No good percentage in that work, I'll have to agree.

Suzuki expert at Brown's Point Marina says, "How old is that motor?"
"Five years, but only 150 hours on it," sez me, somewhat sheepishly.

"Yep, that's why Suzuki says to change the impeller every year. You really need to break open that case each year, especially for salt water usage, even though the impeller might be fine."
"But I was pretty surprised at how easily those stainless bolts sheared!"

"Not stainless, they're a specially coated steel. Stainless would be a disaster. And, whatever you do, don't use Anti-sieze for that application ... constantly immersed in salt water, it will freeze them worse ... just a thin coating of marine bearing grease!"
"So, what now??"

"Use liberal penetrating oil and propane, it's not hot enough to hurt the aluminum. Be careful of lighting-off the oil. Repeat each couple of hours, give the the oil time to work."
"If you're lucky, there's stub-enuf to grab with vice-grips ..."
"Actually ... NOT."

"Then you'll need to drill 'em & heli-coil ... don't even try an EZout, nine-of-ten you'll just snap it off."
"Hmmmm ... thanks."


Sooooo ... Open the lower case and change the impeller each year. It's really pretty easy if the bolts aren't frozen. Just one hour, start to finish, after you know what's up. On the positive side, after five years on EFI, the plugs look fine, no leaks, no drips, no other issues ... this motor is a marvel of packaging.

[kmclemore]

Ugh.. sorry to hear your tale of woe, Frank!

As far as the studs, it's likely they were steel and have siezed in the aluminum due to bivalent corrosion... pretty common, and it's a b*tch when it happens.

I'm not sure what your motor looks like, but would it be possible to heat the casing around the studs? Alloy will expand a lot faster than the steel and if you can heat that casing quickly you might be able to twist out the studs, but you gotta act fast before the stud starts to really heat up (if it does, hit it with some water or even cold-spray if you have some, then give it a twist.)

If the heat can't or won't work, then a reasonably good machinist can carefully drill out the studs and pick out the threads - they come out like a spring if you do it right - and then you're good to go. Failing that, you can just drill to next oversize and use a threaded insert.

When you finally do get those studs out, though, be sure to reinstall the new ones with some copper-based anti-sieze and torque the new bolts to about 10-15% less than you normally would.

[Don T]

Hello:
Well, now that you've broken them off, this is a little late. The secret is WD-40 and slowly working the bolt back and forth until it loosens. Don't let it get too hot cuz that means the aluminum is galling. Tapping with a hammer to break loose the corrosion and let the WD-40 work into the threads may work too. If it still won't come out then apply heat, as in propane torch. Expand the aluminum away from the stainless bolt.
Any amount of time spent working a bolt out is worth it.

Now, you are left with accurately drilling the exact center out of the bolt. An easyout may not work so the last option is to drill out the entire center leaving only the threads which you peal out with needle nose pliers. If you miss and the drill gets into the aluminum you will end up installing a helicoil.

[Robert]

I use Kroil, and like it much better than WD40, same sort of stuff though. A little bit of Kroil on the lug nuts helped get the rust off to prevent busting the nuts or shearing the lugs.
..
http://www.kanolabs.com/
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Other hindsight: If downtime is a problem, don't do service interupting maintenance while the parts supply is closed. It was a strict rule where I used to work not to take any system out of service after lunch on Friday to preserve that it would be working over the weekend. At home I replaced all the incoming plumbing for the well water system, new 120 gallon pressure tank, filters, regulator, relief valve etc.. Never took the system down while the hardware store was closed because I'd never hear the end of having to spend a night without water from the admiral.

[BK]

Sorry to hear about those bolts Frank. I think I wll let the mechanic take a look at mine as it has been 4-5 years with no water impeller change and they might be frozen the same as yours.

[argonaut]

I'm guessing this was the first impeller in 5 years. Guys if you've never had a peek "down there", this is what could happen if you ignore your WP for too long.

I personally think a shaft-driven water pump on the business end of an outboard is an insane design that begs for problems but that's just me. Water pumps probably keep marine mechanics in business.

I've never seen aluminum used in bolts.
The water pumps are often steel bolts into aluminum castings these days, which is a perfect recipe for a galvanic death-grip per Kmclemore, particularly in salt warer. I think that's why the mfgr recommends yearly impeller replacement. It's not because the impellers get eaten up that often (unless it's a Honda) but because those fasteners will gall if they're ignored too long and -that- is a royal pain fixing.

A machine shop should be able to extract them without much trouble. I say don't stress out, just enjoy the holiday. Easy-outs are wonderful things in the right hands, with the right tools and petrochemicals. There's probably about an inch of threaded bolt left in there. Needless to say good quality hardware and some anti-sieze when you reassemble it, and use a torque wrench.
Hope you're back in the water soon, I know what it's like to have a motor ruin your sailing. The price we pay for both worlds is both sets of problems!

[Frank C]

Thanks Guys. Guess that's why the Suzi dealer charges 250 bucks ... if he screws up, he pays to correct it. I don't mind payin' them, but once I make that choice, I hate to wait six weeks on their calendar ... even dentists are more accomodating than "Outboard Dealers."

Kevin, I'm pretty sure that heat will work well, but I'd rather have a tradesman do it ... somethin' about having been there before.

Don, pretty sure that I should have hammer-rapped those bolts and seeped some WD40 overnight. The main-case bolts were 13mm & very hard to break free. I used a short handle and applied steady pressure ... bet the hammer would have helped there too. There was definite galling, bits of metal flaking down out of those holes (shoulda been a clue).

The water pump uses 12mm and they simply twisted off ... betting only 20 lbs. Now that they're buried studs, I'm thinking the water pump cover serves as a centering jig, of sorts.

Robert, good point about holiday weekend, no services, but I'm getting ready for that ten-hour drive to Channel Islands. This long weekend was my only choice to get some things done (well, only "remaining" choice). If things go well on Tuesday I might still hook up by next Saturday.

THanks again ... good advice to remember & ideas to evaluate that Trades guy. Might snap a photo later today.

[ALX357]

Frank,
This will not help you now, ecxept to know you are not alone. I was replacing my trim anode, had the old one off, had started the SS bolt back on by hand.... it seemed to be threading ok, so after it became tighter, i used a normal socket and short wrench... it became harder to turn, so i started to back it out....
... next thing i had the bolt head in the wrench and the rest of the bolt stuck in the aluminum lower housing. I let a dealer guy try to bite the stub end with a vice-grip, and torch-heat the aluminum around the hole, trying to turn it out, and managed to wear off the rest of the stub but NO OUT.
>>>> next , to a recommended maching shop, where they did a procedure of welding on a new hex cap to the bolt, ( lots of nice arc-welding heat to the lower case ) . Bolt head breaks off....
REPEAT 13 times, machinist and me very frustrated, but kindly no charge....
Then motor had a new cooling problem, dealer says impeller (recently new) has lost its flex, .. is limp. TOO MUCH HEAT .... new new impeller, and more $ down the hole.
Still have NO trim anode on motor. It's a trailer-slip boat, so the lack of an anode is not too much missed right now, and my ring-prop seems to have minimized the torque-steer, but i still plan to spend alot of time drilling out, grinding out, easy-outing and so forth to get the bolt out and a new one in....
Boat is a hole in the water where you pour money. Still i love my bigMAC.

[Sloop John B]

I just ordered some Kroil, something under $9. I did the busted bolt on the aluminum block of my Deere. Snapped a few back outs and eventually drilled it out but had to replace with larger hole & bolt.

I noticed the guy putting on my lower casing greasing the bolts. I have always greased my spark plugs, never knowing why, just copying what I'd seen. Wish I'd greased my helm hub last time I had the wheel off. Maybe that Never Seize Kevin mentioned is better. That's what I use on all my stainless hardware. I'd read that stainless is not a good conductor of heat, so it builds up and causes seizure (galling). Have to go real slow with it.

[kmclemore]

HERE is the stuff I recommend for antisieze when working with aluminum - the copper content in this product will better help prevent the galling of stainless against aluminum than the silvery stuff, particularly in a water jacket. This is also the best anti-sieze to use when heat is a problem (brakes, etc.)

I buy the bottles with the brush inside - keeps the mess down.

[Frank C]

Mid-course UPDATE:
Still fighting with sheared bolts in my lower drive casting, so I'm going to miss the Ch. Islands cruise, but I'll be sure to get some Bay sailing instead, maybe some lake-time too.

I posted the mid-course corrections above, and edited the thread title to help avoid this problem for Suzuki owners and future hapless vacationers. Turns out I might have gone to this season's end (again) without changing the impeller. I discovered a glob of goop was blocking the tell-tale port.

Shoulda believed the multi-gauge - no overheating indications. As mentioned at top, once you open it up, this outboard is a marvel - except for monitoring the water jackets, it's virtually maintenance free.
My bad!

[Tony D-26X_SusieQ]

Maybe there is something to the saying: "Don't fix it unless it's broken."

[Frank C]

The gearcase was ready today. The machinist snapped off the fourth bolt too, so I only actually "removed" one of the four waterpump bolts. He drilled out the other three and sleeved them with carbon steel Time-serts - cost $120.

What are the specific advantages of TIME-SERT over Helicoil?

The TIME-SERT inserts have a flange, which will give them a positive placement on installation, for "accurate specific depths". This ensures that the insert does not wind down into the threaded hole. TIME-SERTs are solid bushing and self locking, TIME-SERT being a solid bushing insert gives it added strength. TIME-SERTs have no messy prongs to break off down in the hole which can be a problem in deep holes. TIME-SERTs are self-locking having an actual locking feature which will prevent them coming out when a bolt is removed, again adding to the advantages over coil types. TIME-SERTs are timed internal to external, which give them a thin wall for tight applications but added strength over the coil styles, and can also use loc-tite, if so desired.

So now that I have steel bolts into (3) steel sleeves (instead of aluminum), I'm wondering why I didn't just ask him to drill & sleeve the fourth?? The only risk I foresee is a steel bolt hanging too low and corroding below the sleeve. I'll make sure the replacement bolts are shorter than the sleeves, and of course, well-greased. If I go with only 3 sleeves, I'll probably bolt it together again tomorrow.
BTW ... that five year old impeller looked just fine!

P.S. come to think, wonder why Suzuki doesn't steel-sleeve
for those bolts that live in the briny? ... just has to be better than steel into aluminum!?!

... bleeder valve which broke off eventually had to be drilled oversize and sleeved back down.

... could actually see individual slivers of the brass valve stuck in the aluminum threads, and I could not get the slivers out of the threads.

... would have been cheaper to throw away the caliper and buy a new one for $65.

... Of the eight valves, only one loosened easily. One broke, and the other six I was able to break loose by first heating with a torch, then hitting them with a shot of freon.

... Even if you don't bleed the brakes every year, you may want to just loosen the valve slightly, then retighten to ensure they don't weld themselves together.

(Which is basically the same thing Suzuki is saying about the waterpump bolts in their aluminum gearcase!)

[Frank C]

End of this story ... I just bought some common steel metric bolts to go into the new steel inserts. Though Suzuki recommended marine grease, I just couldn't accept any wisdom in that. Now that I have 3 bolts steel-on-steel, I went with cupric Never-Seize by Starbrite.

The Suzuki guidelines say that the steel-on-aluminum bolts must be thoroughly coated with silicone adhesive ... so be it. I'll pull it apart again at season's end, or maybe in the spring. Glad it's back together.

After reassembling the gearcase I gave the boat a full wash tonight. Much improved! Also hooked up the hose to flush the motor ... looks good, water flowing everywhere. Thanks for advice.