Engine Case Sealant

[etemplet]

I spent some time last night searching the forum for Case sealant for the 787 engine assembly that is about to begin. I ordered Motoseal which I found on amazon with a Prime Delivery. I am not sure I want to use the product if there is something better. I read that this stuff can set up quickly an cause problems. It should be here tomorrow.

At the local motorcycle shop I found Hondabond HT but would not purchase it because I was not sure it was equal to the Hondabond 4. that has been recommended. Is the HondaBond HT good to use?

I don't know where to purchase the Three Bond 1184 locally. I checked the Auto Parts stores online but could not find it. I am asking questions cuz I only want to do this ONCE. LOL Thanks for any input.

 

[Matt Braley]

1184 is kind of a quick dry also. Threebond 1211 is the best for case halves traditionally but it's probably not available locally and I'm sure there are a lot of other good products out there. Hondabond has always been mentioned as a fav but I'm not familiar with the differences in their stuff.

 

[etemplet]

1184 is kind of a quick dry also. Threebond 1211 is the best for case halves traditionally but it's probably not available locally and I'm sure there are a lot of other good products out there. Hondabond has always been mentioned as a fav but I'm not familiar with the differences in their stuff.

I see the 1211 on Amazon. I am considering ordering it but the Motoseal is due in today and it seems to be a good product. I am not concerned about the stuff setting up too quickly. I am going to fit everything first and have everything ready to go before I coat the surfaces with sealant.

Any advice or precautions ??

 

[mikidymac]

Motoseal is perfect to use. It is the same as the Yamabond, Hondabond, and 1184. Some will say 1211 is better but I say 1184 is better. It’s a personal preference but I have been using the 1184 on cases for 25 years.

Put the crank in the top case half upside down supported by blocks so the rods can hang free. Align the balancer shaft and set in the end plug. Then coat both case halves with a thin coat of the Motoseal. Assemble the halves, put the proper sealant on the bolts and torque them to spec in the pattern shown in the manual.

 

[etemplet]

Thank you mikidymac !! I saw a guy on a video use a small roller to apply the sealant but that looked wasteful because the roller will suck up the sealant. How do you guys apply? Small brush, 1 inch with the bristles cut short??

 

[Matt Braley]

Dab it with a clean finger. Remember just a thin coat is enough and it will have that orange peal look. If you have pre-97 cases then you need to add your once of 30 weight oil to the crank and and counter gear area before you put the bottom case piece on.

I'm sure the surfaces are well prepped right? Like a paint job, it's all in the prep. I start with a flat razor but make sure it's not digging into the aluminum. Then I use emory cloth (black wet/dry sand paper) with a flat block behind it to shine things up. I wipe the surfaces with acetone and then let that dry for 10 minutes before I start dabbing the sealant.

 

[etemplet]

Of course Matt. I use a stone on the surfaces in addition. I saw something about the ounce of 30 wt oil and will give that a look. I always spend an egregious amount of time with final prep. I have not checked for timing marks on the balance shaft so I hope they are quite obvious. I will be tapping out and cleaning all the bolt holes as well. Then I'll have to align everything. My goal is next Wednesday to be putting the finishing touches of the whole project. Please keep the info coming if anything comes to mind. Thanks for the help.

 

[mikidymac]

I use a small wooden stick almost like the stem of a Q-Tip to spread the sealant. Got a bunch of them 20 years ago from somewhere, doctors office?

Check out post #56 in my HX Resto thread. Shows the stick and cases.

You can also add the balancer oil through the small bearing lube hole on the top case the rear of the PTO cylinder before you put the jugs on, it just takes longer.

 

[etemplet]

If you have pre-97 cases then you need to add your once of 30 weight oil to the crank and and counter gear area before you put the bottom case piece on.

Matt, I can't find place to add the ounce of 30 wt. I guess the case I have is 1997.

 

[mikidymac]

Nope, those are 96’ cases because it looks like the fill hole is still cast aluminum.
I just add it in the rear bearing oil hole after the cases are together but before the cylinders. It just is slow to fill.

 

[etemplet]

So where is the fill hole ? I went out to check and still can't figure out what you guys are talking about. LOL

 

[mikidymac]

When you have the top right side up at the rear cylinder there is a dished area with a small hole in it.

 

[etemplet]

Sure wasn't where I was looking. Thanks. 30wt oil and not premix oil. Would anyone care to explain the why's of this procedure? Beyond the obvious need for oil which I assume it is for the bearing or seal area. Is this done for the front bearing as well? Sorry I Have not looked much into the assembly because I am busy with other things but before I begin, I will have all the info and the input of the group is most valuable and greatly appreciated.

 

[mikidymac]

I would use synthetic 2 stroke oil as that is what will eventually make its way down there from the premix.
That oil lubricates the rear crank bearings, rear balancer bearing and the gears between the crank and balancer. The front balancer bearing is sealed and also separated byte two balancer seals.
For some reason seadoo changed from two stroke oil to 30w but nobody knows why and either are fine. The 951 uses 30w but that is separate from the crank bearing and premix unlike the 787.

 

[etemplet]

Thanks so much for clearing that up for me mikidymac.

 

[mikidymac]

Any time [emoji106]

 

[etemplet]

Okie Dokie,
Sorry but I Have not looked at the manual yet... heck that wouldn't be a trick. LOL I am just messing around with the fitment of the cases and internal organs. The Balance Shaft alignment to the crank can be a bit tedious. I took a couple of pictures of its current location I was looking for that exact "one Tooth" timing mark where everything looks great. This is a close as I got it. I will now refer to my manual and await responses. One thing I noticed when I took the other engine apart was they had some kind of sealant on the seal grooves in the casing (the thin seals on the crankshaft). Is that something that should be done?

 

[Matt Braley]

Putting case sealant around the outside of the inner crank seals is probably not in the service manual but it is a good practice. I've seen it in the instructions on aftermarket cranks(Hot Rods). I've learned why the hard way. When engines leak oil from the rv chamber into the cylinders it's almost always seeping in from around the outside of the seal.

 

[racerxxx]

Motoseal is perfect to use. It is the same as the Yamabond, Hondabond, and 1184. Some will say 1211 is better but I say 1184 is better. It’s a personal preference but I have been using the 1184 on cases for 25 years.

Put the crank in the top case half upside down supported by blocks so the rods can hang free. Align the balancer shaft and set in the end plug. Then coat both case halves with a thin coat of the Motoseal. Assemble the halves, put the proper sealant on the bolts and torque them to spec in the pattern shown in the manual.

Instead of blocks, I use the long cylinder bolts. Works like a dream.

 

[etemplet]

Question. What lubes the gear mesh on the balance shaft?? Where does the oil to this area come from ?? I am looking but cannot find the path. Does it come through the bearing?

 

[mikidymac]

It lubes from the same oil I was saying to put down the case hole. ALso same oil that lubes the rear crank bearings.

 

[etemplet]

Yea, I was just trying to figure out how the oil GETs where it is needed. The gears are my current concern but the bearing is right there as well. I am very tempted to put some oil in there for start up. LOL Books only tell so much and not the why's an how's. Thankfully people share their insights and knowledge.

 

[mikidymac]

Yes, you need 1 oz (30 ml) of oil in there before you start it.

 

[etemplet]

My syringes came in today so I am ready to inject some sweet rock and roll into this thing.

 

[mikidymac]

Mainlining some XPS will do her wonders.