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3rd motor , same side. Help !

Matthew Dombrowski

Jet Boat Lover
Messages
18
Reaction score
0
Points
80
Boat Make
Yamaha
Year
2007
Boat Model
SX
Boat Length
23
I installed my engine on port side for the third time. First time happened when a lack of maintenance on the engines from a previous owner led to a broken spark plug. NIGHTMARE. Pulled the heads and all of the spacers came off with it in order to easy out or heli coil the head. Long of the short - had a mechanic so he says he was one rebuild it. NOT CHECKING FOR VALVE CLEARANCE AFTER SETTING THE TIMING- Used the STARTER BUTTON! BOOM ? (engine number 1)

Engine 2 - SBT MOTOR, 1 year warranty. Leaked from the valve cover as soon as I transferred all the parts over. SBT sent me a new valve cover gasket, I changed it out. Got another 2 uses out of the boat and same engine BOOM ? - under warranty SBT swapped my motor. They got
It back and that was that. New motor OTW

Engine 3 - stripped the engine out. Used the manual , torqued it all down in my buddies shop. Used the proper lock tight, transferred everything all good ! According to the Yamaha manual. Triple checked it. I just took my boat out. Oil return hose from the cooler to the air box blew off. Oil dripping , checked the level , resecured it. Kept it moving. At 8500-9000 peak rpms. Went another 10 minutes toward the Statue of Liberty and BOOM ? engine shuts down and blew all
The oil out of the valve cover gasket side half moons opposite of the oil cooler side. I shove them back into place , fill it up with oil. Spun the key. Fires up , and I go another 2 mins watching the valve cover gasket. 5000 rpm , blows out - shut it down. Plug the intake and I start the miserable ride of motoring home on one motor. WHAT IN THE **** Can I check to solve this problem. SBT says might be oil pressure is too high( I don’t disagree - it blew out the valve cover gasket) , a respectable mechanic brought up blow by (I agree as well) as a for sure problem. What should
My oil pressure be in a non HO MR1 and will the oil catch can solve my problem or just band aid it. Is is possible that my oil pump bearings are letting oil escape ? What are my options here and what should
I look at. I’m in the boat deep already as you all can see. At this point I want the thing to be fixed and when I figure out what boat I can write off in NJ. That’s the boat I’ll buy. I’m too far committed into this boat to back out of it. (Speakers, ELECTONICS, wrap , lights , interior)
 
I'm sorry this must be frustrating as hell...

To clarify your current situation...Valve Cover gasket is toast. Any chance a new gasket is all it needs?

The oil dipstick normally shows nothing to very little oil when engine is cold and oil is at the right level. I know you are not overfilling it but it's worth mentioning. Good thing is the forum has some smart people that will swing by with good ideas. Hang in there.
 
If I understand you, the cylinder head was accidentally turned upside down and all the intake and exhaust lifters and spacers fell out?
 
Beach bummer- yes the oil levels are for sure correct. I don’t think the valve cover gasket would fix my issue. Something is building too much pressure and that’s the first exit that the pressure can release from. Could be blow by - could be something else - but what is it ? What can build pressure so high in my boat that it’ll blow that valve cover gasket and not blow the one that’s on SBT dyno when it left them.

Wreks - that was on the first motor and yes my buddy flipped it over taking it off the boat and boom - every cap hit the ground. Long behind me is that problem as I bought 2 complete long blocks and returned that for a core.
 
Because I'm not a mechanic I'm going to ask a really stupid question: When SBT sends you a new motor, why wouldn't you just install it straight from the crate instead of tearing it down and rebuilding it?
 
I thought the breather tube ensured there was no "pressure" build up on the valve cover. oil is supposed to be flowing but not pressurized under the valve cover, right?
 
@Matthew Dombrowski Do you have a service manual? @Beachbummer I think the valve cover is pressurized-more by what is happening under the pistons in the crankcase than by the oil pump. Someone please correct me if I am wrong.
 

Not our engine by any means, but I think this is how it works. No high pressure under the valve covers.


Some cars have the filler on the cover, I remember peeking in there while the car is running with no ill effects (except a little splatter)
 
@anmut i installed it direct from SBT / didn’t take apart a thing.

yes I have a manual. I didn’t notice a spot in the manual that is related to my problem. let’s see what happens at the mechanic with it now. I’m more interested in why such high pressure in comparison to the other motor.
 
Is the breather tube blocked or pinched and is tank vent free if obstructions
 
In my knowledge yes, the line is ran as a straight shot with no kinks from the oil cooler to the air box. Maybe I seal this shit up with form a gasket and the valve cover gasket and keep it pushing. Something is causing this engine to have immense pressure.
 
Is it possible you overfilled with oil? @Beachbummer mentioned it in a previous post. Sometimes the dipstick does not tell the true level, especially if the oil can drain back into the sump leaving the oil cooler practically empty. If the element at the bottom of the air case gets saturated with oil, (the hose that blew off connects to that), pressure could build. That element is pictured on pages 4-9 through 4-11 of the service manual up at the top/middle of the pages.
 
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I’m I reading it right that two different engines from SBT have had high oil pressure?

What parts are getting swapped when you put in the new reman engines? Are you using a break in oil?
 
Hey so I’m using all the stock parts back swapping from one to another. The SBT engines come with the valve cover installed already and the oil pan. I removed the rear gear assembly, magneto, and basically the full rear gears and oil cooler. Exhaust. It’s a long block set up. So you swap and torque it to spec. But this side engines are building high pressure and I can’t keep them from blowing valve covers and basically engines. Everything appears correct and I think the game
Plan is a an oil catch can (external). Meanwhile - the other side -
Same set up - no problems after a valve cover leak I sealed up with RTV and the oem gasket. So I’m wondering if I seal up the port side engine and make an external generic oil pressure gauge
 
Is it possible you overfilled with oil? @Beachbummer mentioned it in a previous post. Sometimes the dipstick does not tell the true level, especially if the oil can drain back into the sump leaving the oil cooler practically empty. If the element at the bottom of the air case gets saturated with oil, (the hose that blew off connects to that), pressure could build. That element is pictured on pages 4-9 through 4-11 of the service manual up at the top/middle of the pages.
For sure that engine has been over filled before with oil - you have a link to that replacement filter ? I know exactly what your referring to on that engine. That thing is probably soaked and building reverse pressure. I can bet on it
 
For sure that engine has been over filled before with oil - you have a link to that replacement filter ? I know exactly what your referring to on that engine. That thing is probably soaked and building reverse pressure. I can bet on it
That is what puzzles me. It does not seem to be listed as a separate part. It may be part of the airbox. 2007 Yamaha SX230 HO (TAN) (SXT1100BF) Intake | Yamaha Sports Plaza. I would call them. The throttle body assembly has to be removed to get to it.
 
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