• This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.

Sealing Crankcase on 787

Status
Not open for further replies.

jforest

Active Member
I'm planning on putting together my crankcase when I get home today. My questions is: Do I apply Loctite 515 to just the mating surfaces of the two halves? Is it necessary to apply any to the outside of the bearings so it seals to the case?

Thanks for your help in advance!
 
I've seen folks lightly coat the bearings OD but they say it's to remove the possibility of chatter in the case. I have always just lightly dabbed the mating surfaces with a clean finger and been fine.
 
I never had luck with loctite. I use threebond 1211.

Sent from my SGH-T889 using Tapatalk
 
Threebond is good stuff you can also use it to LIGHTLY coat your base gasket also. Thanks for the tip on that one racer!
144.jpg


It's hard to find local though I got mine from ebay
http://m.ebay.com/itm/161475458517?nav=SEARCH


Sent from my iPhone using Tapatalk
 
This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.
What issues do you have with Loctite 515? I ordered that and should get it today. I was planning on putting the crankcase together tonight. Can you pick up the threebond locally or does it need to be ordered?
 
The loctite is not as forgiving. I had an engine that kept frying a mag piston. So when I pressure tested the engine I found leaks in the cases. I was using the loctite, to get past it I made a call to GroupK (pwc performance shop) and was instructed to use threebond. It sealed on the first time. Loctite will never seal another case for me. If you look at my clapped out thread you'll see my case halves with the threebond and also in my 95 xp800 thread. You may have better results.

Sent from my SGH-T889 using Tapatalk
 
The problem with the loctite 515/518 is that it is not fuel resistant. It was made to be a flange sealant not an engine case selalant and I am not sure why seadoo ever used it for this. Every other manufacturer uses a silicone based product for this. You need to use either Threebond 1211, 1194, Honda Bond 4, or Yamabond 4. Any motorcycle shop should have one or the other. The way to apply it is a very very thin coat on both surfaces of each case half then assemble quickly. Make sure you do use the loctite 515 and thread lock on the bolts as the manual states. You do not need sealer on the bearings as they will be sealed by the crank seals to the cases.
 
I called around and found a shop that has the yamabond. I was planning on going there anyways to pick up some XP-S oil today so I will get the yamabond while I'm there.

Thanks for your help :cheers:
 
That is why we are here. Make sure you print the page of the manual that shows not only the torque specs but also the order to tighten the bolts in as there is a pattern. Also if you look at the age in the manual where the cases are blown up at the beginning of the chapter is shows what bolts get 515 and thread lock. Good to know because some get thread lock and 515.
 
515 is specifically not recommended for aluminum, according to the spec sheet no?

518 should work fine though, Hylomar and Yamabond, are a couple more.. There are others as well but I wouldn't use 515 either.
 
The problem with the loctite 515/518 is that it is not fuel resistant. It was made to be a flange sealant not an engine case selalant and I am not sure why seadoo ever used it for this. Every other manufacturer uses a silicone based product for this. You need to use either Threebond 1211, 1194, Honda Bond 4, or Yamabond 4. Any motorcycle shop should have one or the other. The way to apply it is a very very thin coat on both surfaces of each case half then assemble quickly. Make sure you do use the loctite 515 and thread lock on the bolts as the manual states. You do not need sealer on the bearings as they will be sealed by the crank seals to the cases.

This ^^^ is a good post, all you need to know.
 
Years ago when I looked into it the 515 was made by Loctite and the 518 was under the Permatex label. Both the same thing made by Loctite. I am not sure what engineer at Rotax decided on the 515 but as far as I know they were the only ones to use it in the power sports industry. I think at one point they revised the manuals to indicate that you needed to use some special primer with it too.

I have always used the Threebond 1194 on all 2 stroke cases, same as Hondabond 4 and Yamabond 4.

The Threebond 1211 is used by a lot of people on the cases but to me it has different properties and is better for a thin coat on gaskets rather than sealing cases.
I use a very thin layer of the 1211 on all paper gaskets, base, carb, MAG cover and exhaust as long as it is not the graphite ones.

I have never had an air leak or failed leak test. Big knock on wood!

All of the Japanese brands and GM now use the 1194 or equivalent for sealing machined aluminum to machined aluminum.

FYI: Permatex now sells a "Motoseal" that looks to be the 1194 equivalent.
 
Last edited by a moderator:
I picked up XPS oil and also picked up yamabond 6b. It is resistant to oil, water and gasoline according to the packaging. Thanks for everyone's input!
 
DO NOT USE THe 6B! Yes I am yelling.

The Yamabond 6B is just a high tmep RTV and not what you want to use on your cases. You need to return it and get the Yamabond 4. Do not listen to the parts geeks behind the counter.
 
Thanks for the heads up! I already opened it so I guess I cannot return it but I will get the right kind. The rotary valve gear is messed up so I have to replace it. I'll order the Threebond 1194.
 
Years ago when I looked into it the 515 was made by Loctite and the 518 was under the Permatex label. Both the same thing made by Loctite. I am not sure what engineer at Rotax decided on the 515 but as far as I know they were the only ones to use it in the power sports industry. I think at one point they revised the manuals to indicate that you needed to use some special primer with it too.

I have always used the Threebond 1194 on all 2 stroke cases, same as Hondabond 4 and Yamabond 4.

The Threebond 1211 is used by a lot of people on the cases but to me it has different properties and is better for a thin coat on gaskets rather than sealing cases.
I use a very thin layer of the 1211 on all paper gaskets, base, carb, MAG cover and exhaust as long as it is not the graphite ones.

I have never had an air leak or failed leak test. Big knock on wood!

All of the Japanese brands and GM now use the 1194 or equivalent for sealing machined aluminum to machined aluminum.

FYI: Permatex now sells a "Motoseal" that looks to be the 1194 equivalent.

515 is FAA approved for aircraft engine cases so that might be where it came from.

I'm with you on the Yamabond 4 though, also GE RTV-102 should work and I've used Permatex Motoseal 1 before as well.

Vatozone shows Motoseal in stock, probably they have it?

http://www.permatex.com/documents/TDS/automotive/29132.pdf
 
Last edited by a moderator:
Not that it really matters but Ski-Doo had been using 515 probably since its been created. Obviously whatever it's supposed to be spec'd for its been in use for 35+ years by Bombardier. Here's a pic of my 1980 shop manual.

#9 "Loctite 515"

attachment.php


Sent from my SGH-T889 using Tapatalk
 

Attachments

  • uploadfromtaptalk1428546212126.jpg
    uploadfromtaptalk1428546212126.jpg
    82.7 KB · Views: 149
My local advance auto has the Motoseal in stock for $8.97. I'm calling to see if a Yamaha dealer close to me has the Yamabond 4. Should I look till I find the yamabond and go with the motoseal as last resort?
 
Just called the local yamaha dealer, they have the Yamabond 4 for $10. I'll be getting that.

Thanks again for everyone's input.
 
hondabond4 yamabond4 and threebond 1194 are all pretty much the same thing. and the stuff is amazing. i've started using it for everything. i fixed a leaking union joint on my well pump and again on my gfs honda. someone had stripped the oil pan plug threads on in the actual pan, smeared it down with threebond and its never leaded a drop since.
 
As far as the 515/518, I know Rotax has used it for years and there are still some 20 year old skis running it from the factory but I wouldn't. The first time I came across it on a SeaDoo I put some gas on a rag and it came off very easy and with no residue so that is when I decided it was not fuel resistant and would be using my trusted 1194.
 
I've been a 1211 man but feel like I'm missing out now. Just ordered the 1194. $12.01 shipped

That's funny Matt.

The application is a little more difficult than the 1211 as it is a little more viscous and tends to make little hair thickness strings. It is semi drying so I spread a very thin layer on each case half as smooth and even as possible then assemble as soon as practical. It does not squeeze out like standard sealant.

Years ago I got a bunch of these but without the cotton tip and they work awesome for application.
download.jpg

One other thing is they keep changing the number to comply with VOC laws. If I remember correctly it used to be 1104 then 1104D and now 1194.
 
Status
Not open for further replies.
Back
Top