2008 FX SHO run without supercharger?

[Bearcatw]

Looking at a used 2008 FX SHO with 165 hours. Supercharger hasn't worked for 4 years. I am happy to run without it, but just wonder if I should be concerned about anything.

[K447]

What do you mean by ‘happy to run without it’?

Has the supercharger been removed from the engine?

If not, then the sprag clutch for the supercharger (inside the front crank housing) is slipping and will be slowly grinding itself down, with the metal particles going into the engine oil

The impeller is sized to match the boosted engine power. Without boost the engine will not have enough torque to spin the impeller to the optimal RPM so the acceleration will be quite sluggish and the top speed will be significantly reduced.

There is a kit available to replace the worn clutch with a newer design, upgraded and more reliable. Look in the GH online store
The upgrade kit will include a new clutch, the matching idler gear and related small parts.

[K447]

Parry Sound, eh?

We are not that far away

Changing a Yamaha supercharger clutch takes a couple of hours, give or take

[Bearcatw]

Franklin Island today

[Bearcatw]

What do you mean by ‘happy to run without it’?

Has the supercharger been removed from the engine?

If not, then the sprag clutch for the supercharger (inside the front crank housing) is slipping and will be slowly grinding itself down, with the metal particles going into the engine oil

The impeller is sized to match the boosted engine power. Without boost the engine will not have enough torque to spin the impeller to the optimal RPM so the acceleration will be quite sluggish and the top speed will be significantly reduced.

There is a kit available to replace the worn clutch with a newer design, upgraded and more reliable. Look in the GH online store
The upgrade kit will include a new clutch, the matching idler gear and related small parts.

Supercharger is still on. Can metal actually get through the fuel system? I'm content with the reduced hp without the supercharger running, but if there's a potential that metal is in the engine, I'll pass on the Ski. I want to get going on this season, and address the supercharger later if that's feasible.

[seabrook]

Supercharger is still on. Can metal actually get through the fuel system? I'm content with the reduced hp without the supercharger running, but if there's a potential that metal is in the engine, I'll pass on the Ski. I want to get going on this season, and address the supercharger later if that's feasible.

LOL!!! this is the best post ever!!!

[K447]

Supercharger is still on. Can metal actually get through the fuel system?

I'm content with the reduced hp without the supercharger running...
I want to get going on this season, and address the supercharger later if that's feasible.

The SHO (and SVHO) Yamaha engines are designed to have a functioning supercharger. The fueling maps and the impeller pitch are set to match the engine power with the expected level of boost.

Without the boost the SHO watercraft will not run like a non-supercharged model. It will run significantly less well. The engine will struggle to reach mid-range RPM despite full squeeze on the throttle lever. The jet pump thrust will be sub-par due to the low RPM. The overall result is a sluggish ride that is slower than a factory HO non-supercharged model.

The supercharger clutch is a wear item and it is normal for the clutch to eventually fail and need replacement. The expectation is that shortly after the clutch begins to slip noticeably and cause reduced engine performance that the engine will be serviced and the clutch replaced. The amount of metal particles shed by the clutch is not supposed to cause problems. In part because the engine would be promptly serviced and the clutch replaced, which includes an oil change.

The engine does have an oil pump and oil filter, which of course will filter hopefully most of the metal particles that may be in the oil.

Do you have any information regarding how many engine running hours have occurred since the SHO clutch began to fail?

[Bearcatw]

The SHO (and SVHO) Yamaha engines are designed to have a functioning supercharger. The fueling maps and the impeller pitch are set to match the engine power with the expected level of boost.

Without the boost the SHO watercraft will not run like a non-supercharged model. It will run significantly less well. The engine will struggle to reach mid-range RPM despite full squeeze on the throttle lever. The jet pump thrust will be sub-par due to the low RPM. The overall result is a sluggish ride that is slower than a factory HO non-supercharged model.

The supercharger clutch is a wear item and it is normal for the clutch to eventually fail and need replacement. The expectation is that shortly after the clutch begins to slip noticeably and cause reduced engine performance that the engine will be serviced and the clutch replaced. The amount of metal particles shed by the clutch is not supposed to cause problems. In part because the engine would be promptly serviced and the clutch replaced, which includes an oil change.

The engine does have an oil pump and oil filter, which of course will filter hopefully most of the metal particles that may be in the oil.

Do you have any information regarding how many engine running hours have occurred since the SHO clutch began to fail?

Thank you for the considered reply. This is exactly the information I was looking for. I will have to do a close inspection on the existing supercharger and determine whether it can be repaired. Also, source the required parts. Don't think I can get hour usage since its been down, but they've only been putting on just over 10 hr/season on average, so hopefully not too high.

[K447]

… do a close inspection on the existing supercharger and determine whether it can be repaired.

Also, source the required parts. ….

There isn’t much to inspect, just looking at the front of the engine. Presuming the supercharger is indeed not providing boost (because the clutch drive has worn and is now slipping) from the outside the engine will look entirely normal. Even if you could directly see the clutch, a worn clutch looks the same as a new clutch. The wear is internal to the the clutch gear unit, which is replaced as an assembly.

Given the engine hours, a clutch wear failure is entirely normal. My expectation is that the clutch (probably the factory original 2008 part) should simply be replaced with the upgraded kit.

As long as the engine does not have some other problems, replacing the clutch should be expected to return the engine to full power and function.

Aside from being supercharged, the normal pre-purchase inspections should be done. Cylinder compression check should confirm that all four cylinders have similar compression and are relatively even across all four.

Note that often a fresh set of spark plugs will restore Yamaha 4-stroke engine performance that has slowly degraded. Even if the spark plugs ‘look good’ it is inexpensive to replace with the correct genuine spark plugs.

The jet pump should also be inspected. Looking up into the water inlet from below the hull, use a strong light to view the impeller. The blades should look smooth and without dings and bent edges. If the jet pump has ingested rocks and dinged up the impeller, repair or replacement of the damaged impeller can restore jet pump thrust.

Also inspect the hull bottom for damage. Beaching abrasion or rock impact damage can be repaired, but known damage should factor into the price you pay for the thing.

Here is a video showing examples of good versus worn Yamaha supercharger clutches
These are all from my own SVHO engine, which has the same clutch design as SHO

[Green Hulk]

Looking at a used 2008 FX SHO with 165 hours. Supercharger hasn't worked for 4 years. I am happy to run without it, but just wonder if I should be concerned about anything.

No, do not run without it. You need to install a new supercharger clutch. You need to be concerned about the clutch failing further and metal shrapnel destroying your engine.
This is the clutch kit you need

https://www.4-tecperformance.com/index.php?main_page=product_info&cPath=349_163&products_id=2084

[seabrook]

Supercharger is still on. Can metal actually get through the fuel system? I'm content with the reduced hp without the supercharger running, but if there's a potential that metal is in the engine, I'll pass on the Ski. I want to get going on this season, and address the supercharger later if that's feasible.

i would not buy that ski- anyone that would run without a sc would do other bad things as well. UNLESS they are giving it away on price- take in mind when my timing chain broke it was 10,000.00 USD for the the block, head and labor (yamaha covered under warranty). So if you buy it and the motor blows up you could have just bought a new ski for what you will pay to replace the motor and head- these are interference motors and usually grenade when they go.