Yamaha Outboard Model 150TXRB 2-Cycle Oil-Injection Technical Improvements

[mrsnipe]

All:
During offshore fishing and equipped with a single 2-cycle 150 HP Yamaha, I worry about three things: weather; salt water/sediment contamination in gas; and loss of injection oil.

Assuming NOAA buoy reports are accurate and my fuel oil separator/filter functions properly, that leaves oil injection as a primary concern. I have following concerns and wonder if other Yamaha owners have similar observations. There were previous reports on WWW of loss of injector oil due to lube oil pump failures in 2-cycle Yamaha's that resulted in internal damage.

My letter to Yamaha is attached. Summarized:

The purpose of this letter is to alert Yamaha Motor Corporation to an operational condition on 2-Cycle Oil-Injection models that requires a technical review. Analysis below is based on the Owner's Manual and Technical Manual descriptions for Model 150TXRB 2-Cycle Oil-Injection system.

My Model 150TXRB 2-Cycle Oil-Injection outboard is currently equipped with the standard tachometer and audible low-level oil alarm. An optional Yamaha Digital Tachometer is available and includes: Tachometer, Trim meter, Hour meter, Oil level indicator, Overheat warning indicator, Set button, and Mode button.

The Digital Tachometer, compared to the standard tachometer and audible alarm, affords additional visual warnings for low oil-injector levels and water jacket temperatures, but both installations are deficient for Yamaha outboards:

There is no pre-check device or operational procedure described to test proper functioning of the low-level audible alarm switch set point. A switch failure preempts engine oil-injector reservoir level indicators.

In event of lube oil pump failures, there is no alarm system for low pump discharge to the three carburetor vapor chambers. The oil level in the outboard oil reservoir will be high or normal but the engine is oil-starved without a visual and or audible alarm.

An optional Yamaha Digital Tachometer includes an Overheat Warning Indicator which would sound at the preset set point for jacket temperature in the event of a loss of oil-injection. This visual alarm, under full load conditions, would probably not allow lead time to prevent further damage to the outboard internals caused by injector-oil starvation.

I recommend Yamaha investigate possible solutions to the issues above in order to make the 2-cycle outboard a more reliable product.

I further propose that a dealer alert bulletin be issued that advises dealers and customers of these potential problems.

Terry Payne
843-308-6720
Charleston SC

Terry Payne
mrsnipe@att.net
Charleston SC
843-308-6720 Wk
843-762-4286 Hm

[GWcpa]

If you assume the NOAA reports are right and you fuel seperator works, why not just assume you oil injection works too?

You don't think yamaha has considered this before? I don't get it.

[KevinM]

Oil injection pumps on Yamaha's are pretty well made all metal gearing and shafts. injectgor pumps of this design have been around for somwhere around 20 some odd years with very little failures. Where there are some reported failures is in the low level sensor on the primary tank not sending the low level oil warning to the ECU, not allowing the ECU to shut down and sound the alarm.
On carbed model Yamaha's oil is injected behind the carbs directly into the cranckase not into the carbs. On EFI models the oil is injected into the VST for mixing with fuel prior to the injectors.

[PeteH]

And I thought I worried to much! The oil injection on my Yami's is about the only thing I don't worry about. After 9 or so yami's dating back to 1985, I've never had issue #1 with low oiling. Snipe on!!!!

"This visual alarm, under full load conditions, would probably not allow lead time to prevent further damage to the outboard internals caused by injector-oil starvation."
"probably"? Yami already has one of the most conservative temp alarm settimgs. Take your engine to a 5 star certified yami shop as infrequently as you can. Of all the posts I've read on different sites where yami's failed due to oiling, I have never seen a report of a failed oil pump. The culprit is usually some monkey who doesn't put the float assembly back in it's proper position. Under that condition you get a failure to oil and no warning. Proper maintenance with OWNER inspection is your only true insurance.

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