85HP Rotax gummy-like substance inside head

[parkericharda]

So I recently had some water coming up through one of the head bolts on an 85 hp (1996) Rotax 2-cycle engine. It is water cooled. I removed all the head bolts, took the top off and notice no cracks or anything, but a weird gummy silicone-like substance (see photo). Now I doubt this is why water is coming up through a head bolt, but thought I should check and see if anyone has any ideas what this substance might be before putting it back together (I bought all new seals). I'm hoping the new seals will be the ticket to preventing water leaking up. I'm thinking that the water is coming from the fact this is a water-cooled engine, and one of the seals is leaking water from one of the passages. Appreciate any additional thoughts on this as well. Also, can anyone tell me if there is some kind of sealant that goes on the head bolts that prevents water, or just the Loctite that holds them in tightly?

 

[Waterluvr]

That's the oil residue left over from using pink -50 RV waterline antifreeze in your aluminum engine which is a real gamble btw. That -50*f rating is labeled on those containers as the burst rating of smooth walled water pipes. That stuff completely freezes at about 18*F and begins to expand in volume from there, it was never intended to be used in any engine ever.

Don't take my word for it, pour a cup of -50* pink RV and put it in your freezer overnight and see what happens.

They sell non toxic -100*f below labeled for engine use with a different oil formulation that wont make you sorry come spring time.

 

[parkericharda]

Is the gummy substance inside okay?

That's the oil residue left over from using pink -50 RV waterline antifreeze in your aluminum engine which is a real gamble btw. That -50*f rating is labeled on those containers as the burst rating of smooth walled water pipes. That stuff completely freezes at about 18*F and begins to expand in volume from there, it was never intended to be used in any engine ever.

Don't take my word for it, pour a cup of -50* pink RV and put it in your freezer overnight and see what happens.

They sell non toxic -100*f below labeled for engine use with a different oil formulation that wont make you sorry come spring time.

Thank you for your recommendation! So is the gummy substance okay to be there or do I need to clean it out? I have always had (to my knowledge) someone certified to do winterization. So I'm not sure what product they have been using. Perhaps I will need to ask about that. It is always garaged in the winter, so hopefully it hasn't caused any true issues to the block and has not been that cold in the garage.

Regarding the water coming up through the head bolt, any ideas? Could it just need some better Loctite in there per specs, or would it moreso be one of the O-rings? I just purchased $75 worth of O-rings for the head, and plan to replace them all, just in case. Also, is there any kind of sealant that goes between the top middle and bottom pieces of the head/block? Or do the bolts just tighten that down and the pressure keeps it from leading into the bolts themselves? There appears to be no seal preventing water to the bolts. Appreciate any other thoughts.

 

[Waterluvr]

By all means while it's opened up take a shop vac to it and get all that out of there, it reduces the volume of your engine's cooling passages and seen I've plenty of small PWC and outboard engines damaged when that gunk stops up a passageway.

You'll see people recommending that garbage (-50 RV/Marine waterline antifreeze) to winterize motors all the time, even right here on this website. It's not formulated or safe for use in aluminum engines or any inboard or I/O iron block and you may have some damage because of it, can't even begin to tell you how many boats came into my shop over the years with broken blocks, heads etc. and there sit the empty jugs in the boat of -50* pink RV they used last fall to try and save a buck.

Read the label on any container of -50* waterline antifreeze and there will be a warning to bypass the water heater in the boat or rv, but they don't elaborate as to why. Fill a water heater with that stuff and you're buying a new one next season.

The non toxic propylene glycol formulations made for engine use all carry -100* labeling and specifically state safe for use in aluminum engines and don't contain any alcohol or corrosive substances. The confusion is essentially comparing the labeling between old school ethylene glycol used in automotive applications versus non toxic propylene, all propylene container labeling is listed as the burst rating for a copper pipe and they solidify at temperatures well above their degree listing unlike traditional ethylene glycol.

Non toxic -50* water line antifreeze formulations are not all the same, you'll find different concentrations of propylene, alcohol and other substances corrosive to aluminum by manufacturer and some of it literally eats away at aluminum while it sits over the winter.

Regarding your leak, there may be some damage on that head from having used it, clean everything up really well and inspect it closely for cracks or damage I suspect the hole around the head bolt is cracked on an edge.

 

[parkericharda]

Interesting. Thanks for the 411!! There's quite a bit of hard water sediment in there as well... should I use like a wire brush or some kind of solution (like CLR) to clean it? Or will that cause damage?

 

[Waterluvr]

You really want to keep chemistry out of the cleaning process if possible when it comes to aluminum, try a stiff bristle brush and hot water with mild detergent first. I see you're from Michigan, I'm 5 minutes from Niles if your close just drop by some evening and toss that in my ultrasonic tank it will remove it without chemicals.

 

[parkericharda]

What about the head bolts... there's a lot of hard water deposits on those as well... do those need to perform any kind of seal, or are they strictly to hold the thing together? In other words, do I need to clean it?

 

[Upallnight]

That's the oil residue left over from using pink -50 RV waterline antifreeze in your aluminum engine which is a real gamble btw. That -50*f rating is labeled on those containers as the burst rating of smooth walled water pipes. That stuff completely freezes at about 18*F and begins to expand in volume from there, it was never intended to be used in any engine ever.

Don't take my word for it, pour a cup of -50* pink RV and put it in your freezer overnight and see what happens.

They sell non toxic -100*f below labeled for engine use with a different oil formulation that wont make you sorry come spring time.

Two senior members of this forum believe that RV ant-freeze is fine.

http://www.seadooforum.com/showthread.php?57271-1999-Speedster-Winterization&p=356674&viewfull=1#post356674

It's even in the winterization stickiy at the top of this forum.

 

[Waterluvr]

What about the head bolts... there's a lot of hard water deposits on those as well... do those need to perform any kind of seal, or are they strictly to hold the thing together? In other words, do I need to clean it?

Clean the bolts and threads best you can, the o-rings seal everything when the bolts are torqued.

 

[USAF_Pride]

Two senior members of this forum believe that RV ant-freeze is fine.

http://www.seadooforum.com/showthread.php?57271-1999-Speedster-Winterization&p=356674&viewfull=1#post356674

It's even in the winterization stickiy at the top of this forum.

Look where they live. How often do you think it gets to 18 degrees where they live? Then look at our temperatures last winter. Despite what a lot of people say, we are in a cooling cycle. Just look at the last few winters.
[MENTION=71806]Waterluvr[/MENTION] - Your PM box is full so I can't respond to you. Send me your email address

 

[Waterluvr]

Look where they live. How often do you think it gets to 18 degrees where they live? Then look at our temperatures last winter. Despite what a lot of people say, we are in a cooling cycle. Just look at the last few winters.

And there's another issue with recommending -50 Rv waterline for engines. Virtually all manufacturers use ethyl alcohol in an oil and propylene suspension base to make it and that's why they specifically state to bypass water heaters in the usage labeling (aluminum water tanks), there is none of it in the -100 non toxic products labeled specifically for engine use.

Ethyl alcohol is extremely corrosive to aluminum engines. Parkericharda's pics are a good example of what happens when it's used. If freeze damage doesn't get you in a cold climate the damage to the aluminum will sooner or later.

 

[Upallnight]

But Ethyl alcohol (Ethanol) is used in most gasoline these day.

Ethanol fuel is ethanol (ethyl alcohol), the same type of alcohol found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. World ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion liters. From 2007 to 2008, the share of ethanol in global gasoline type fuel use increased from 3.7% to 5.4%.[1] In 2011 worldwide ethanol fuel production reached 22.36 billion U.S. liquid gallons (bg) (84.6 billion liters), with the United States as the top producer with 13.9 bg (52.6 billion liters), accounting for 62.2% of global production, followed by Brazil with 5.6 bg (21.1 billion liters).[2] Ethanol fuel has a "gasoline gallon equivalency" (GGE) value of 1.5 US gallons (5.7 L), which means 1.5 gallons of ethanol produces the energy of one gallon of gasoline.[3]

 

[parkericharda]

Torque ratings for head bolts

Clean the bolts and threads best you can, the o-rings seal everything when the bolts are torqued.

Where can I find the proper torque ratings for the head bolts?

 

[Waterluvr]

Where can I find the proper torque ratings for the head bolts?

Coat threads with 242 blue, final torque is 17 ft. lbs. Here's a diagram for the 787, same sequence for the 717/720 series.

 

[vission]

[MENTION=71806]Waterluvr[/MENTION],

Do you have any links to recommended antifreeze, many of us will be performing our winterizations soon.

 

[Waterluvr]

[MENTION=71806]Waterluvr[/MENTION],

Do you have any links to recommended antifreeze, many of us will be performing our winterizations soon.

Go see your local marina, in cold climates most of them stock -50 waterline and -100 non toxic for marine engine applications. If you need to order it here's just one of many brands available that's safe to use and alcohol free. For any Rotax 2-stroke motor application two quarts will be plenty so a gallon is all you need for a twin engine boat.

http://www.westmarine.com/buy/west-...ine-water-system-antifreeze--P004_134_004_500

 

[parkericharda]

By all means while it's opened up take a shop vac to it and get all that out of there, it reduces the volume of your engine's cooling passages and seen I've plenty of small PWC and outboard engines damaged when that gunk stops up a passageway.

You'll see people recommending that garbage (-50 RV/Marine waterline antifreeze) to winterize motors all the time, even right here on this website. It's not formulated or safe for use in aluminum engines or any inboard or I/O iron block and you may have some damage because of it, can't even begin to tell you how many boats came into my shop over the years with broken blocks, heads etc. and there sit the empty jugs in the boat of -50* pink RV they used last fall to try and save a buck.

Read the label on any container of -50* waterline antifreeze and there will be a warning to bypass the water heater in the boat or rv, but they don't elaborate as to why. Fill a water heater with that stuff and you're buying a new one next season.

The non toxic propylene glycol formulations made for engine use all carry -100* labeling and specifically state safe for use in aluminum engines and don't contain any alcohol or corrosive substances. The confusion is essentially comparing the labeling between old school ethylene glycol used in automotive applications versus non toxic propylene, all propylene container labeling is listed as the burst rating for a copper pipe and they solidify at temperatures well above their degree listing unlike traditional ethylene glycol.

Non toxic -50* water line antifreeze formulations are not all the same, you'll find different concentrations of propylene, alcohol and other substances corrosive to aluminum by manufacturer and some of it literally eats away at aluminum while it sits over the winter.

Regarding your leak, there may be some damage on that head from having used it, clean everything up really well and inspect it closely for cracks or damage I suspect the hole around the head bolt is cracked on an edge.

Are there any other areas that water passes through, or just at the top there? Just curious if this is the only place water could be leaking through around the head bolt, or if there is water cooling that happens farther down in the block.

 

[Waterluvr]

Are there any other areas that water passes through, or just at the top there? Just curious if this is the only place water could be leaking through around the head bolt, or if there is water cooling that happens farther down in the block.

Water travels to the base of the cylinder cooling jackets just above the area where they mount to the crankcase, assuming you have removed the bolts and only taken off the head cover your not able to see down into the cylinder water jackets yet.

You should probably removed the head and make sure there's no freeze or corrosion damage affecting the combustion chamber itself, better to catch that early on than be steam cleaning the oil film off your pistons and rings as the engine is running.