(mss9.9b2) 9.9 hp Oil light comes on

[vdotmatrix]

I am trying to figue out what would cause the oil light to come on? It has oil....

 

[pvanv]

The oil lamp comes on if the sender wire for the pressure switch is grounded. So, in normal operation, once the pressure is above about 4 psi, the light is off. If the switch is damaged, or if the wire is damaged and grounding, that could cause the LED to light. It is also possible for a bad CD to always think that the wire is grounded.

If the oil is very overfilled, it could foam up, and the bubbles can compress, causing actual low oil pressure. If the oil is almost empty, air in the system could cause a low pressure. If the motor is really overheated, the oil will be thin, and can have low pressure.

I would take out the sender and put a test gauge on the motor to confirm pressure. It should be between 4 psi and 40 psi, depending on RPM, oil kind, and temperature. If the actual pressure is good, you are getting a false trigger. Assuming the wiring is good, at that point, I would install a new pressure sender switch and re-check.

 

[vdotmatrix]

The oil lamp comes on if the sender wire for the pressure switch is grounded. So, in normal operation, once the pressure is above about 4 psi, the light is off. If the switch is damaged, or if the wire is damaged and grounding, that could cause the LED to light. It is also possible for a bad CD to always think that the wire is grounded.

If the oil is very overfilled, it could foam up, and the bubbles can compress, causing actual low oil pressure. If the oil is almost empty, air in the system could cause a low pressure. If the motor is really overheated, the oil will be thin, and can have low pressure.

I would take out the sender and put a test gauge on the motor to confirm pressure. It should be between 4 psi and 40 psi, depending on RPM, oil kind, and temperature. If the actual pressure is good, you are getting a false trigger. Assuming the wiring is good, at that point, I would install a new pressure sender switch and re-check.

THANK YOU PAUL. I took the motor back to the shop and they could not duplicate the condition. NOW the motor won't start....I purged the fuel line the check valves seem to work.. The only other thing is perhaps they didnt VENT the can while the motor was running creating a fuel lock.

Another question, we have a remote on this setup....Is the paddle on the remote , the choke?

 

[vdotmatrix]

I will remember the sending unit troubleshooting if it happens again....thank you

 

[pvanv]

The MFS9.9B2 does not have a choke, You can DL your owners manual at
https://tohatsu.com/tech_info/manuals.html
On p 14, it explains the neutral warm up lever operation.
Check plugs. If wet, no spark. If dry, no fuel.

 

[vdotmatrix]

We are still having issues with this motor. I replaced the 15 year old bulb on the fuel line. Thinking that it was loosing prime or something...

someone used the boat today and here is what the report said:

The engine started OK at the dock, warmed up well and ran OK at 3/4 power all the way to the end of The Channel. Once on the main channel the engine cut off at 1/4 power. We were able to start it and it ran well at 3/4 power but it cut off again at 1/4 power.

I disconnect the motor and I take the motor to the shop. Then I reconnect the cable linkages from motor to the remote....can i reconnect the motor wrong to cause this? It ran just fine for me at the dock for 15 mins...

I tell people it is not a choke , it is a warm up lever and i send them the picture of it on p.38.

thanks

 

[pvanv]

We are still having issues with this motor. I replaced the 15 year old bulb on the fuel line. Thinking that it was loosing prime or something...

someone used the boat today and here is what the report said:

The engine started OK at the dock, warmed up well and ran OK at 3/4 power all the way to the end of The Channel. Once on the main channel the engine cut off at 1/4 power. We were able to start it and it ran well at 3/4 power but it cut off again at 1/4 power.

I disconnect the motor and I take the motor to the shop. Then I reconnect the cable linkages from motor to the remote....can i reconnect the motor wrong to cause this? It ran just fine for me at the dock for 15 mins...

I tell people it is not a choke , it is a warm up lever and i send them the picture of it on p.38.

thanks

Time to dx whether there is a fuel propblem (likely) or a spark issue. Start at the beginning. Verify no o-ring leaks or obstructions in the fuel system all the way to the carb. Make sure carb is clean. Check condition of spark plug. Check for proper spark. Are you still getting an oil light? No, I can't imagine connecting an RC causing that issue.

 

[vdotmatrix]

there is only one way to connect the rc and there us a bracket that holds the cable at a precise position.

 

[vdotmatrix]

no oil light lamp illumination.

 

[vdotmatrix]

I am disconnecting the motor again, and carting it down to the shop.

 

[vdotmatrix]

they checked the compression did everything except check the carb where I think the problem lies.