B Pipe Fit

[Mike W]

It was running fine from a propulsion standpoint (I think) until that last little test ride.

Alright, well she's fully stripped and here are the highlights:

Everything looks to be fine. Has minor cavitation marks on the prop but shouldn’t be your issue. But that hull to pump seal is definitely suspect. I would replace that with a new one at a minimum.

 

[Storbeck]

I would for sure suspect that pump seal as your issue.

 

[chylez]

Yeah it looks like the seal was pinched on the top side.

Should I pull the prop and redo the bearings while I'm this far?

Both cylinders tested at 142psi and it looks like I'll have to rig something up to do the other casing test.

 

[mikidymac]

Judging from the wear on your midshaft coupler your engine is way out of alignment too.

 

[chylez]

Can do Compression Tests with Engine out of Hull. Just need Battery, Starter and Jumper Cables preferably with Remote Start Switch. Make sure to remove and insert Spark Plugs into Plug Boots and ground them onto the Cylinder Head.

Then, follow with an Air Leak-down Test to find any potential Air Leaks. Maybe that Crankcase is leaking. Leave the Intake Manifold and the Exhaust Manifold on, plug the Holes, reinstall Spark Plugs, then pressurize thru the Pulse Line to 8 psi. Needs to hold 8 psi for 10 mins.

These two Tests will narrow down the list of possible issues with your Engine.

Compression test showed 142 on both cylinders.

Allright I finally got the leak down test set up with the exhaust and intake holes plugged. I had to make a temporary gasket out of a rubber fiber sheet as the gasket for the intake manifold was leaking from pulling it open to remove the carbs. It does not hold pressure. It leaks off nearly as fast as i pump it in.

I ran a soapy sponge over everything I could see including the air valves to see if I could find a leak but I did not find anything. I installed the front manifold to see if it was leaking behind the flywheel but I couldn't find a leak their either. I didn't pull the flywheel, I just installed the cover and checked to see if it build up pressure.

Where else should I be looking?

 

[Quinc]

Make sure your sparkplugs are screwed in tight. And spray the whole thing with soapy water. You should be able to see a leak that big right away.

 

[chylez]

Make sure your sparkplugs are screwed in tight. And spray the whole thing with soapy water. You should be able to see a leak that big right away.

Yeah I soaked the dang thing lol. I just went back and did it again too for good measure : (

That cheap gasket material I used is pretty weak but it should hold 8 psi.... maybe I'll oil it and reinstall and see what that gets me.

 

[Quinc]

Also spray around your gauge and pump to make sure its not leaking there.

 

[chylez]

Yeah the first thing i did was check my little jank pump. It has to be this gasket I put it in. It must not be able to hold air. I'll have to figure out something else for a gasket.

 

[chylez]

After you pump 8 psi into the Engine, take the Pump Head off the Schrader Valve or the Schrader Valve will bleed all the Air out (like deflating a Car Tire prank), unless there is another Check Valve in front of the Schrader Valve.

Soap that JB Weld Repair on the Crankcase. Flip the Engine and soap the Crankcase Bottom. Might be missing a big chunk of Case. If so, post photos in Carnage Section

Soap both Crank Seals. Soap all Mating Surfaces and Bolt Heads. Soap the Rubber Stopper Plugs. Soap the entire Test Rig, including the Pressure Gauge.

If the leak is big, should be able to hear the pressurized Air escaping from the Leak Source.

You won't be able to pump Air into the Engine fast enough unless you're a Pro Golf Caddy. I typically use a high volume Bicycle Tire Pump because it can fill the Engine before all the Air leaks out. Gives you some time to find the leak. Best to use an Air Compressor with Regulator set at 8psi and let it pump Air constantly till you find the crack or leak.

Thanks JC, will do and I'll report back. Gonna have to wait on the gasket to arrive for the intake manifold.

Does anyone recognize what brand of intake manifold it is that I have? Looks like a flying W on the top right of the part?

 

[mikidymac]

The flying W would be Westcoast Performance.

 

[SRQski]

Other place to check for a leak - exhaust manifold water jacket. Plug the water inlet and see if it changes. If so, you have a leak into the water jacket where manifold mates up to cylinders. Had that on a motor, drove me nuts trying to find it.

Sent from my SM-G991U1 using Tapatalk

 

[chylez]

So I ordered a 61X intake gasket and it doesn't fit... Is this a 650 crankcase on a 61X upper? I'm missing something here lol

 

[jetfreak78]

So I ordered a 61X intake gasket and it doesn't fit... Is this a 650 crankcase on a 61X upper? I'm missing something here lol

6m6 case

 

[chylez]

Ok I finally got my gasket set for the 6m6 and I did find two very slight leaks on the head above the exhaust manifold. I had to plug the cooling lines to even find it. Going to order some new gaskets and keep testing.

 

[chylez]

Which product should be used to seal the head since the AM Pro-Tec pipe does not take a gasket. The Pro-Tec guys said blue or black RTV but there are quite a few products that are blue/black rtv...

Edit: The permatex ultra black gasket maker is the product to use.