787 Block-off kit for pressure testing

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racerxxx

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Ok, so some of you guys have commented about my pressure testing kit. This kit is mimicked off the kit that Bombardier has shown in their service manual. I use this to pre-test the engine BEFORE and AFTER a rebuild. I use it before to check for any internal leaks that could pop up from say a bad winterizing job and cracked a cylinder jacket etc... You can check several areas on the 787. You can check the Rotary Valve seals, engine cooling passages and the top end and the bottom end. The procedure and flow chart is in the service manual. I tried using rubber for gaskets, they didn't work very well so I prefer to use OEM gaskets. I use hi-temp RTV on the exhaust portions of the kit and on both sides of the gaskets and for the carb flange gaskets I use gaskets from a Speedster jet boat (204250035), they measure almost .125 thick(real thick) compared to .021 for a ski I use Threebond 1211 on them. When I test I use the Mityvac hand pump, you can get them at auto parts stores and harbor freight (http://www.harborfreight.com/mityvac-vacuum-pump-39522.html), I run this through a 1/4" ball valve available at Home Depot, Lowes, or plumbing supply store, and I have the valve inline so when I reach 5 psi I close the ball valve, just to eliminate any leaking that could come from the hand pump. You can also use an air compressor--BUT REGULATE IT DOWN TO 5 PSI, this will save you on needing the hand pump. You can make a soap/water solution to spray on the engine and watch for air bubbles to find your external leak, the internal leaks are covered in the manual. In the following picture is what you will receive EXCEPT the fitting, the Hand pump and gaskets, you're only getting the block off plates. You'll get two RAVE block offs, two CARB block offs, and one Head Pipe block off all made from 3/8" thick aluminum. I also use vacuum plugs that are available at your local auto parts store, I use them for the oil injection nipples, fuel pump pulse line, water cooling fittings and finally the Rotary Valve in/out fittings. I use push to connect fittings designed for air lines, we use them at work for our equipment. You'll need to come up with an adapter for what ever size lines you'll use. I could provide all this but it will take the price too high, so I'm keeping this kit to the basic plates and you can be resourceful to gather the rest and cobble with what you have. I will be glad to answer ANY questions you might have to get you started.

Now to the nitty gritty. The kits will be $65.00 plus shipping. I'll work this two ways, I'll gladly ship via USPS and will get you the shipping charges BEFORE you pay OR if you have your own UPS account I'll gladly ship using your account and have it bill direct to you. I do not charge more than what I get charged and no handling fees. I try to keep from using the USPS boxes as they are charging you for them--they're NOT FREE, the flat fee is usually more than what I can ship it for using a box I supply/recycle--I try to keep everything on the cheap, so how ever get it there cheaper is how it will go. I typically ship USPS Priority Mail. I will ship North of the border, EH!

So to start I'm getting these made in quantities of 5, so I'll have the first 5 made once five guys post up they want a set. I really don't want to go too far out on the line for these as I'm not sure how many are interested. The current delivery is 3 to 4 weeks, the water jet runs non stop all day so they have to "fit" me in. I'm not pulling down mega bucks making these, by the time Paypal gets their cut, my time to get them, pack them and ship them it's just about a wash on what I'm paying for them. I'm just doing it for the fun of the hobby to be honest, I have a full time business and it does not revolve around boating. I do service work and travel so there may be times I'm not around to possibly ship, but can usually figure something out and can respond.

Attn Mods, if this is in the wrong section feel free to move it.


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Good luck with the sales. :cheers:



I was going to do a set from my shop... but I figured that there wasn't enough people who wanted to dig that deep into their engines. BUT... it's a highly useful tool.

One suggestion.... if you can fit O-ring seals to them... they will have a more reliable seal if there is a warp, or light damage to the flanges.
 
Good luck with the sales. :cheers:



I was going to do a set from my shop... but I figured that there wasn't enough people who wanted to dig that deep into their engines. BUT... it's a highly useful tool.

One suggestion.... if you can fit O-ring seals to them... they will have a more reliable seal if there is a warp, or light damage to the flanges.


Yes O-rings would be great, but only the carb flanges would benefit from that as they would be the easiest to do. The head pipe needs to seal both the water jackets and the exhaust from that water jackets, so that would be 3 o-rings to hold in place, and the RAVES would be weird at best. Not to mention these are going to be cut on a water jet, then I'd need fixturing to set it up in the CNC and also begging for the CNC time. The price would go up even more if I had to do that stuff, just trying to keep it simple and effective. RTV will make up for any imperfection in the mating surfaces. Some of the leaks I have see are actually through the gaskets themselves, not the sealing surfaces. I had an aftermarket head pipe gasket that was fiber/mesh like, man did that thing leak like a sieve. I've had great results with OEM gaskets and a small amount of sealant. Typically you can rub the RTV off the OEM gaskets and then use the gasket on the engine. And yes these are a very useful tool to have in the shop. I love making specialty tools for one off jobs.
 
Racer....I am also in on the block off kit. I actually have some very nice rubber gaskets, but I'd like your block-offs so I dont have to use a manifold.

Ok, so you want a manifold block off plate then? The original price I quoted was for what is pictured above LESS the Mity Vac and the quick disconnect.

I'll try to post up the other pics later, trying to winterize the Speedster right now and get it in my neighbors barn before we get this friggin Nor' Easter with 1-3" of white gold.
 
Yup I want the complete kit...I have a nice pressure tester. Or are you using vacuum?

I'd like mine to have a 1/4" barbed fitting on it, and I have the hardware.

I'd also like a mani cover for the 580-720. I can use a late model 720 single carb mani w/ the 40mm 787 cap.
 
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I use pressure, I either use my Mity Vac or I use my air compressor with the regulator set to 5 psi.
 
Yes O-rings would be great, but only the carb flanges would benefit from that as they would be the easiest to do. The head pipe needs to seal both the water jackets and the exhaust from that water jackets, so that would be 3 o-rings to hold in place, and the RAVES would be weird at best. Not to mention these are going to be cut on a water jet, then I'd need fixturing to set it up in the CNC and also begging for the CNC time. The price would go up even more if I had to do that stuff, just trying to keep it simple and effective. RTV will make up for any imperfection in the mating surfaces. Some of the leaks I have see are actually through the gaskets themselves, not the sealing surfaces. I had an aftermarket head pipe gasket that was fiber/mesh like, man did that thing leak like a sieve. I've had great results with OEM gaskets and a small amount of sealant. Typically you can rub the RTV off the OEM gaskets and then use the gasket on the engine. And yes these are a very useful tool to have in the shop. I love making specialty tools for one off jobs.


Awesome work!

Would it be better to leave the water jackets vented to outside air & not sealed durring tests anyway? this way if the engine holds the right vacuum you would be testing the seal between the water jackets & the inside of the engine. Then, if there was a leak in the water jackets, it would just be water into the boat hull & not into the enigne.
 
Nope, because you need to check to see if there are internal water leaks(bad gasket leaking or a crack in a jacket etc..), the procedure in the service manual tells you how to completely pressure test the crankcase, cooling system and the rotary valve seals. You want ZERO leaks anywhere.
 
Nevermind, thinking further, I guess you already have it that way with the coolant lines at the bottom of the cylinders & the head, just leave those oepn to test.

Sorry wasn't thinking fully ;)
 
Nope, because you need to check to see if there are internal water leaks(bad gasket leaking or a crack in a jacket etc..), the procedure in the service manual tells you how to completely pressure test the crankcase, cooling system and the rotary valve seals. You want ZERO leaks anywhere.

But in therory, with your manifold block off plate. you could seperate the cooling & enigne side to test them independantly as well, to make sure there is no leak between the two, correct?
 
But in therory, with your manifold block off plate. you could seperate the cooling & enigne side to test them independantly as well, to make sure there is no leak between the two, correct?

Yes you could use one of the fittings on the backside of the cylinder and just cap the other one on the other cylinder. The original kit that I intended to sell was modeled after the OEM kit, which was meant to use in the hull for trouble shooting. Now I keep making cover plates and guys are wanting them too---I need to stop posting pics of my goodies or you guys just need to move next door to me and borrow my stuff:D
 
I was supposed to finish the CAD drawings last week. We'll work had other priorities, I was supposed to be on the road one day last week, ended up being 5 days, 4 customers, and another 1000 miles. So next week I'll wrap them up and get them to the waterjet. This brings me to the next scenario the plates.

I originally was making the OEM style kit (1st pic), then others saw my exhaust manifold block off plate (2nd pic) and I also made the carb block off plate(3rd pic) which is used in conjunction with one of the rotary valve block off plates to allow you to bead blast your carbs to resto them. SO the first kit was going to be $65 plus shipping, to add just the extra carb block off plate that is an extra $11. I still need to get the pricing for the exhaust manifold block off plate. That is the final CAD drawing I need to finish. What would work ideal is if I knew who wanted that one so I can get a better price on that when I get all of these cut. I'm going to get 5 completes sets of the OEM kits made with the extra carb plate and would prefer to ship them like that is the kits for $76 plus shipping, then if you want the exhaust manifold plate that will be extra.

I know I have been talking about the kits for a while now but the work load looks like I might be a bit slow coming up and I can get this little side project done. Sorry for dragging my feet. If anyone else reading this wants a set please let me know this is probably going to be a one time deal so it's easier to get 6,7, or 8 kits cut at once.

So I know Matt, JSG, SSelzer, Spim??(I think?) Just let me know we still have some time yet. Your kits are all going to be so much nicer than my saw cut ones!

Original kit
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Exhaust Manifold block off
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Carb kit(left side one)
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What's the carb kit for? They need to come off if you do a leak down. The shaft seals on the carbs aren't designed for pressure. (they are a vacuum seal) Also... the choke shaft isn't sealed. (well) AND... even if you block off the hoses... the pressure isn't good on the diaphragms.

If it's for some other reason... let me know. My brain is roasted right now, and I may have missed something.
 
Tony its so you can paint them...


I will take a full kit; I would sure appreciate if you could do an exhaust block off for the 580-720 and a kit for the 951s too. As far as I know the OEM kits have been discontinued.

I have rubber "plates" for everything under the sun you use instead of gaskets to do a leak down test...but I would MUCH rather use plates instead of having to bolt up a mani over them. They were waterjet cut so if you want me to send them out to you to use as templates let me know. I think I have all the kawis, and some polaris and yamis.
 
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What's the carb kit for? They need to come off if you do a leak down. The shaft seals on the carbs aren't designed for pressure. (they are a vacuum seal) Also... the choke shaft isn't sealed. (well) AND... even if you block off the hoses... the pressure isn't good on the diaphragms.

If it's for some other reason... let me know. My brain is roasted right now, and I may have missed something.


So you can bead blast your nasty corroded carbs and repaint them and make them look brand new. And no you DO NOT bead blast the insides, they were polished with a very small fine stainless steel brush in a cordless drill. So yes DOC no pressure testing the carbs, sorry it's sort of a mixed thread crossing over from my Clapped Out thread--sorry.

From this:
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To this:

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TO THIS!!!!:thumbsup:


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I'd be interested in a set if I could get an extra plate for a 717 as well. Lmk if you make one and I'll paypal you the money. Thanks!
 
I'd be interested in a set if I could get an extra plate for a 717 as well. Lmk if you make one and I'll paypal you the money. Thanks!

You want the one for the top of the exhaust manifold? I'll need to get a gasket at the dealer and measure it up but I'll see what I can whip up, shouldn't be a problem. I guess I'll need one for my 720 in my HX too, eventually.
 
Yeah I believe so. I haven't went out to the garage and looked at the difference in the 717 and 787 but I remember there being one. Send me a PM if you get one made up and I'll send you the money. I'm not in a real big hurry, I cant build the engine for a couple more months since I still have a messed up hand.
 
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