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Pressure test rotary valve

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Gary pope

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I just got done replacing the outter bearings and seals on my 97 720 motor. Got both crankcase halves put back together and I’m wondering if I can pressure test the rotary valve by plugging off one of the holes and I’m pretty sure I can thread my leak down tester on the other one. How many psi should I put in tgere and how long should it be able to hold?
 
8 psi for at least 10 minutes.

You really don’t need to pressure test it separately as when you test the complete engine you will also be testing those seals.
 
Well....it’s a good thing I did because when I pressurized it, I could hear air hissing from between the two halves on the opposite side as the rotary valve.... so what I did was tore it back apart, rtv’d the crap out of it around the area where it was leaking because when I took it apart and cleaned it thoroughly I couldn’t see any nicks or cracks or anything like that so I just caked the crap out of it, put it back together and torqued them down to specs. If I recall they were 17 & 30 ft lbs
 
Wait, your leak was between the cases, or at the crank seals? Are you using RTV to seal the case halves?
 
It was coming from between the cases right where there’s a space you can put a flat head screwdriver in tgere to pry the cases apart.
 
DO NOT USE RTV! It is not fuel proof and will leak destroying your engine.

You have been given the correct method on this numerous times but don’t seem to want to listen. I’m not trying to be a jerk but trying to get you to do it correctly and have a trouble free build.

You need to clean all the RTV off and use a thin layer of 1211 or 1185 or Yamabond on both surfaces then use the proper treatment on the bolts and torque to spec.

If it is still leaking on that pry point the cases are trash and must be replaced.
 
OK I can’t seem to find any of the Yama bond So what is an equivalent that I can get in an auto parts store? I’ve been to AutoZone O’Reillys advance
 
I don't recall either of those carrying these sealants. I've always had to order mine online. Sorry, but that's the nature of the beast. Not sure what they have that can be a suitable substitute.
 
Get some 51813 permatex / 518 loctite to seal the cases. Available at your local parts store.. I use it on everything.
 
OK I can’t seem to find any of the Yama bond So what is an equivalent that I can get in an auto parts store? I’ve been to AutoZone O’Reillys advance

Yamaha dealers will have Yamabond Honda dealers have Hondabond, Car parts stores typically have Permatex MotoSeal and 1184 is all the same thing. The manual will tell you what to put on the bolts, follow it exactly to the T.
 
Get some 51813 permatex / 518 loctite to seal the cases. Available at your local parts store.. I use it on everything.

I know this is what the factory used but I strongly disagree with this statement. IF you take any old cases the 518 rubs off immediately with gas on a rag and in some places is hard. Every other engine manufacturer uses an elastic, fuel proof sealant like 1211 or 1184 (Yamabond, Hondabond). Ask any top engine builder and they will all say 1211 or 1184. In my personal opinion 518 is not the correct product to use.

If you do choose to use it you should follow seadoo's tips in using a roller to spread a smooth even coat of 518 not just squirt a bead out of the tube as any that squeezes out will not dry as it is an anaerobic sealant. The only part that will cure is the area directly between the cases.
 
I know this is what the factory used but I strongly disagree with this statement. IF you take any old cases the 518 rubs off immediately with gas on a rag and in some places is hard. Every other engine manufacturer uses an elastic, fuel proof sealant like 1211 or 1184 (Yamabond, Hondabond). Ask any top engine builder and they will all say 1211 or 1184. In my personal opinion 518 is not the correct product to use.

If you do choose to use it you should follow seadoo's tips in using a roller to spread a smooth even coat of 518 not just squirt a bead out of the tube as any that squeezes out will not dry as it is an anaerobic sealant. The only part that will cure is the area directly between the cases.

I've used 1211, 1184, and 518. I've never had a single issue with any one of them, I always have a dozen tubes of the 518 around because:
1. it works as locktite.. so there's no screwing around with that. Sea Doo used that stuff EVERYWHERE, so why not.
2. it's available locally if I'm in a pinch. - which is what was being asked
3. it tastes THE best. Slightly peppery, with a hint of wang tang.

I do order 1211 three at a time, but have never had a failure out of 518.
 
It could be. I use nothing but Three Bond 1211 on all the PWC engines. I just finished a 4-tec and a 947. I'm now in the process of rebuilding a 787. Next in the lineup, a Yamaha 4-stroke, a Kawasaki 750, another 4-tec, another 947, and a 717.

Chester
 
I know everybody uses 1211 on the cases but I prefer the 1184. It is what every Japanese OEM uses on 2-stroke cases and even GM is starting to use it on most of their aluminum engines. I also like it because you have a little longer working time than 1211 and it seems to spread out easier on the case halves.
 
Ok I got the yamabond today, so I should be good to go to put the two halves together right then use the loctite on the bolts?
 
OK I have a question. I had a mishap while assembling the other motor so I had to order a new top part of the crank case. Now that I have it together there is a slight difference in the services were they meet up I mean I’m not even talking millimeters of a difference but you can feel the difference, is this OK.
 

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