IS THIS ROTARY VALVE BAD??

[mejim707]

I'm at my wits end with this. I pulled the RV and I see lines in it, but nothing I can catch my finger on. There is a small groove in the block because the RV had a little nick in it and cause that groove in the block, but again, it's not enough to catch my finger nail on.

The RV is smooth for the most part. I can feel the fluctuations in the metal but again, not to catch my finger nail.

Lastly, the cover looks fairly newly machines, at least it has the vertical lines for oil.

I checked the clearance with the solder method. I put the solder in the top and bottom of the RV holding it in there with a little grease. I torqued to 15 FT/Pounds and measured the thickness and both solder pieces are at exactly 0.125.

To me this is fine, however, I still cannot start on water warm. This starts in water cold no problem, and runs awesome and smooth! But when I stop it, it will not start after I wait. I can start it right up after stopping, but if I wait it will absolutely refuse to start.

Please help!! I will gladly get a new RV and cover if I have to but SBT will take almost 20 or more business days for a turn around.

 

[POPPS]

could be a coil failure,,,it warms up and fails…could even be a poor ground somewhere,,

 

[mejim707]

could be a coil failure,,,it warms up and fails…could even be a poor ground somewhere,,

Thank you! Does the RV look bad from the pictures?

Also, if it was a bad coil, or a ground issue, would I still get a strong spark? I bought an inline spark tester and the spark seems to be firing as expect on both cylinders. I'll try anything at this point, but that spark test shows a solid spark so I was thinking the ignition system was working properly.

I don't know. I'm questioning everything. I really thought I had it...

 

[TheGTIjetguy]

Have you tried dribbling some gas down the intake to see if it will fire?

 

[mejim707]

Have you tried dribbling some gas down the intake to see if it will fire?

Thank you for the reply!

Yes I tried that and I also tried taking the plugs out and dribbling a little directly into the cylinders but it didn't even try to fire.

Also, I can shut it off hot and turn it right on within a minute or two in water. If I wait a few minutes there is no way I can turn it on. I need to get it out of water and wait few minutes and it'll fire right up after 15 minutes when I get home. I can turn it on in water cold no problem. It runs awesome with no problem. When I get back to the dock and shut it off I can turn it right on within a few minutes with no problem. It's only when I wait longer. This seems the opposite of something overheating and causing the issue.

PLEASE NOTE: I hear water clearly and steadily dribbling into the exhaust while I sits there. This doesn't seem right. It's a constant dribble, like the faucet on very low dribbling into a pan. Should this happen? Should water constantly and steadily dribble into the exhaust? The Pipe is angled up into the hull. The only thing I can think is it's coming in from the pump and getting through the water regulator and pouring into the exhaust.

 

[TheGTIjetguy]

You may be onto something. A water box that has filled up and blocked the exhaust certainly won’t allow it to start. Also explains the no-start after time issue.
Unfortunately I’ve never messed with a water regulator, hopefully someone with more experience can chime in.

 

[POPPS]

there should not be any dribbling sounds,in the hull of a watercraft,,,unless it is slowly sinking.

 

[mejim707]

there should not be any dribbling sounds,in the hull of a watercraft,,,unless it is slowly sinking.

It sounds like it’s coming into the water box or resonator. I don’t think it happens cold, but I’m going to check now.

Can the water regulator cause water to dribble into the resonator? Or whatever the canister is that’s connected to the tuned pipe with the rubber hose?

No water at all is getting into the hull however.

 

[POPPS]

Since it starts well just after you stop,,,I am now leaning toward fuel getting/dripping/leaking into the carb throats,,.(when the RV clearance is off they are very very difficult to start immediately),,,
Next cold startup,,,let it idle,,,and loo down the carb throats,,,see if fuel is dripping?..perhaps you have a needle and seat that sticking open,,,rare,,,but can happen,,,or,,,the “O” ring on the seat is leaking,,,even the gasket at the bottom of the regulator,,may be pinched,,,,is the transparent anti sy phone valve there?,,,I would go thru the carbs with a surgeons fine toothed comb,
Let us know,

 

[mejim707]

I figured out my starting issue on water when hot!!!!!!!

The water regulator was allowing water to dribble into the resonator. And the main hose from the pump was also contributing.

A guy got stuck at the dock, and since I couldn't start the boat I was stuck with him blocked in. I took that time to track down the dribbling sound. I had hose clamps with me so I clamped off both the water regulator water hoses as well as the main water hose from the pump.

I then was like, screw it lets try to start with the hose clamps on and sure enough it fired up with no issues whatsoever! It was absolutely refusing to start the entire time until I clamped off those hoses and it fired up instantly!!! Of course I immediately shut it off since I wasn't going to run without water circulating. I took the clamps off and it fired up without issue!

I figured out why it wasn't starting! Now, I need to figure out why these hoses are causing this.

QUESTIONS:
Is the water regulator supposed to dribble water into the resonator while the boat sits?
Is the main water hose supposed to be held up and not laying in the hull?
Is there some valve or anything that should prevent water from bogging the exhaust out when sitting in water?

Any advice on how the hoses are supposed to be routed or if they're supposed to be elevated would be great. But at least now I know the cause!

I'm sooo stoked man you have no idea. I've been fighting with this issue for a very long time!

 

[mejim707]

Since it starts well just after you stop,,,I am now leaning toward fuel getting/dripping/leaking into the carb throats,,.(when the RV clearance is off they are very very difficult to start immediately),,,
Next cold startup,,,let it idle,,,and loo down the carb throats,,,see if fuel is dripping?..perhaps you have a needle and seat that sticking open,,,rare,,,but can happen,,,or,,,the “O” ring on the seat is leaking,,,even the gasket at the bottom of the regulator,,may be pinched,,,,is the transparent anti sy phone valve there?,,,I would go thru the carbs with a surgeons fine toothed comb,
Let us know,

POPPS!

I figured out my starting issue on water when hot!!!!!!!

The water regulator was allowing water to dribble into the resonator. And the main hose from the pump was also contributing.

A guy got stuck at the dock, and since I couldn't start the boat I was stuck with him blocked in. I took that time to track down the dribbling sound. I had hose clamps with me so I clamped off both the water regulator water hoses as well as the main water hose from the pump.

I then was like, screw it lets try to start with the hose clamps on and sure enough it fired up with no issues whatsoever! It was absolutely refusing to start the entire time until I clamped off those hoses and it fired up instantly!!! Of course I immediately shut it off since I wasn't going to run without water circulating. I took the clamps off and it fired up without issue!

I figured out why it wasn't starting! Now, I need to figure out why these hoses are causing this.

QUESTIONS:
Is the water regulator supposed to dribble water into the resonator while the boat sits?
Is the main water hose supposed to be held up and not laying in the hull?
Is there some valve or anything that should prevent water from bogging the exhaust out when sitting in water?

Any advice on how the hoses are supposed to be routed or if they're supposed to be elevated would be great. But at least now I know the cause!

I'm sooo stoked man you have no idea. I've been fighting with this issue for a very long time!

 

[mejim707]

This is the current hose routing. It seems correct. But, the main water inlet form the pump seems like a very long hose and I don't recall ever seeing the water line this long.

Could the fact it's laying at the bottom like that, and being that it's so long, could that be why this prevents me from starting on the water when hot? Something to do with these hoses is off and causing my issue.

 

[mikidymac]

Hose routing looks ok. No, the water regulator doesn’t seal off and shouldn’t cause a no start.

But this looks like a boat so the routing could be different.

 

[mikidymac]

This is a boat so the water routing could be different and skis don’t have the fiberglass resonator.

Replace the rotary valve as it looks bad.

Cover looks ok.

If that groove in the case picture connects the two ports it will leak vacuum pulse and the cases are trash.

 

[mejim707]

Hose routing looks ok. No, the water regulator doesn’t seal off and shouldn’t cause a no start.

But this looks like a boat so the routing could be different.

Thank you! I have a new rotary valve on its way and should be here Friday. I got it from SBT.

Do you have any idea why I have to pinch off the inlet water hose in order to start the boat?

 

[mejim707]

This is a boat so the water routing could be different and skis don’t have the fiberglass resonator.

Replace the rotary valve as it looks bad.

Cover looks ok.

If that groove in the case picture connects the two ports it will leak vacuum pulse and the cases are trash.

Hi, I have a new RV coming Friday. I'll replace it with the fresh one form SBT.
However, it seems that the starting issue is the water getting into the exhaust too much while the boat sits and only happens after running it for a while. When it's cold sitting in water there is no dribbling sound. I go out for a while, then park at the dock and the water is pouring into the exhaust from the water regulator. I hear it clearly.

The water regulator is allowing water to actively dribble / pour into the tank / resonator connected to the tuned pipe. And I can start it every time without issue so long as I pinch off the hoses going to the water regulator, as well as the main hose coming in from the pump to the engine for cooling. I pinch them off, and it fires right up after it seemingly clears the standing water out. I immediately turn it off, remove the clamps, then fire it back up without issue. That's the only way it'll start after running.

Any idea why this would happen? Is the water regulator supposed to allow water to actively pour into the exhaust when the boat sits?

 

[etemplet]

I have Speedster outside and I'll have to take a look. As @mikidymac said the routing looks OK from what I can see.
My thoughts are: There isn't that much water in the water system to flood anything when the engine is not running so I don't think it could be the water control valve preventing a start. If the resonator had too much water in it, where did the water inside the resonator go when you clamped the water control valve feed? It wouldn't instantly drain anything.

Clamping the water inlet and the engine starting tells me to look at the head gasekt and cylinder. That will prevent the engine from starting. If the engine fired right up with no problems that tells me your rotary valve may not be the problem. I'd pull the head and have a look.

You never know though, these things are sneaky. Good Luck !!

 

[mejim707]

I have Speedster outside and I'll have to take a look. As @mikidymac said the routing looks OK from what I can see.
My thoughts are: There isn't that much water in the water system to flood anything when the engine is not running so I don't think it could be the water control valve preventing a start. If the resonator had too much water in it, where did the water inside the resonator go when you clamped the water control valve feed? It wouldn't instantly drain anything.

Clamping the water inlet and the engine starting tells me to look at the head gasekt and cylinder. That will prevent the engine from starting. If the engine fired right up with no problems that tells me your rotary valve may not be the problem. I'd pull the head and have a look.

You never know though, these things are sneaky. Good Luck !!

If it was the head gasket I would see water in the cylinders wouldn't I? I would check the plugs and they would be dry.

But after clamping the hoses, and trying to start for a few seconds I think this is purging the water that's filling the exhaust and when it clears it fires up without issue.

Then I shut it off, take the clamps off, and it fires up instantly.

But like I said too, I hear water actively dribbling / pouring into the resonator only when the engine is warm. This never happens cold. That's what led me to pinch off the lines and sure enough it starts every single time.

Incidentally, I have no overheating, the plugs stay dry and a nice medium brown without fouling, and the engine stays warm to the touch on the exhaust and jugs even after running it at 7k for 30+ minutes. I can't get past 45 MPH, but I can do 45 on choppy water with a full tank so I'm thinking the engine is running as its supposed to.

It is a bazaar issue, but I know the water is filling the exhaust while it sits, and only when it's warm, I just have no clue why.

 

[etemplet]

Something else to think about, which I don't think is your problem, is that the fittings and elbows for the cooling water system are specific sizes for the locations. While externally the fittings look the same the size the hole in the fittings are different (there is a number on the fittings). This balances the flow of water through the system.

Can the resonator go bad internally??

 

[mejim707]

Something else to think about, which I don't think is your problem, is that the fittings and elbows for the cooling water system are specific sizes for the locations. While externally the fittings look the same the size the hole in the fittings are different (there is a number on the fittings). This balances the flow of water through the system.

Can the resonator go bad internally??

Good question, I don't know if the resonator can fail like that but it's worth pulling and inspecting.

And I'll absolutely check the numbers on the fittings. Who knows, the previous owner could have changed things out with incorrect parts (while consuming too many brews lol) and cause this odd issue. I'll go take a look at those this afternoon!

 

[etemplet]

I'd remove the water control valve with the boat in the water and observe what is going on.

I'm wondering if engine hot and cold is coinciding with boat IN and OUT of the water. In other words, " you just drop the boat in the water and started it up cold or did the boat sit in the water overnight and engine cold on start up."

 

[mejim707]

I'd remove the water control valve with the boat in the water and observe what is going on.

I'm wondering if engine hot and cold is coinciding with boat IN and OUT of the water. In other words, " you just drop the boat in the water and started it up cold or did the boat sit in the water overnight and engine cold on start up."

Good call, I never tried to remove the regulator while it sits for fear it would gush water and sink lol I'll give that a shot to see what it's doing. It sounds like it's pouring into the exhaust through the post / shaft that attaches to the resonator.

And when I get to the dock I launch the boat, without starting it all day and just let it sit there not running. I go do my thing, park the car and take my time getting to the boat. There is no sound of water flowing or dribbling. And I can start it right up with no issues no matter how long it sits there.

But, if I run it and park, I hear as clear as day water running into the exhaust and it does not stop until I pinch off the lines.

 

[etemplet]

I bought a speedster last year for $2k and I"m going to replace both the engines I restore skis as a hobby and I don't like working on boats so I'm trying to figure out how stupid I was buying this thing. It is in good physical condition though. Maybe I"ll like it when I finish but I gotta start first.

 

[etemplet]

Good call, I never tried to remove the regulator while it sits for fear it would gush water and sink lol I'll give that a shot to see what it's doing. It sounds like it's pouring into the exhaust through the post / shaft that attaches to the resonator.

And when I get to the dock I launch the boat, without starting it all day and just let it sit there not running. I go do my thing, park the car and take my time getting to the boat. There is no sound of water flowing or dribbling. And I can start it right up with no issues no matter how long it sits there.

But, if I run it and park, I hear as clear as day water running into the exhaust and it does not stop until I pinch off the lines.

Well that sure narrows it down. Good job identifying the issue. At least now you can work to resolve it.

 

[etemplet]

By the way in your other thread, that Rotary needs replacing and the surface on the engine said isn't all that bad. Good Luck.