[22Angler]

I have twin 200 yamaha's (1993) I was cruising at normal speed (approx 4000 RPM) and my stbd engine began to vibrate and dropped RPM's to approx 3000. The Alarm went off but stopped as soon as I put into neutral so I started running again. It ran fine for approx 5 minutes and then did the samething again. I stopped, turned engine off, tilted it up to see if I had anything on the props but did not see anything. I also looked at the remote and main oil tanks and both had an adequate level of oil. The temp guages also where fine. I started the engine again and it ran fine the rest of the ride home (approx 10 minutes). What could have caused the engine to go into SLOW mode. Also, if it went into SLOW due to overheating I do not believe that it would have run fine without sitting for a few minutes to cool down. Any ideas?

[22Angler]

Any thoughts or ideas?

[cousinabe]

what are the model numbers of the engines?

maint history:
1) how old are the thermostats?
2) when was the water pump changed?

were there any indicators lit up on the gauges?
am also thinking it could be a loose battery connection??

[22Angler]

T-Stats are 2-3 years old
Impeller changed every 2 years.

The engine was not overheating as the temp guages showed normal temp and engine did not seem excessevily hot to the touch.

[rodbolt]

when was the last time the remote oil tank filter was changed?
what did the oil indicators on the dash show?
your describing a restricted remote tank oil filter.
low battery alarm can trigger slow as well but on that year would be indicated on the yamaha digital speedo.
in any case BOTH engines should have gone into RPM reduction if the correct ign switch panal was used.

[22Angler]

The indicators on the guages are not working as the guages are 15 years old but the alarm went off. You are correct that both motors went into SLOW mode but I narrowed it down to the stbd motor by reducing the throttle one at a time and noticing when the alarm shut-off.

I did think of dirty filters at the remote tank but since these where both changed less than 1 year ago,the remote and main oil tanks had adequated oil in them and the engines ran fine once I backed off the throttle I did not persue. Would the alarm go off even if there was adequate oil in the tanks? Are there any sensors which monitor the rate of flow of oil not just the level in the tanks?

Yesterday I removed the main tank sendors from both motors, thinking that maybe they were stuck in a low oil position. I re-installed on the opposite motors and ran the boat for approx 20 mintues at all speeds (idle, WOT, cruise) but could not replicate the problem. What are the chances of a problem with the sendor which rectified itself by removeing and re-installing? I am worried that the problem still exists but the 20 minutes which I ran the boat was not long enough.

Thank you very much for your help with this.

[cousinabe]

Did you perform the 180 second oil transfer test?

Make sure the remote tank is at leats 1/2 full, with the key on and engine off cut the tie strap and carefully remove the water trap from the engine tank,drain the tank into a container until the alarm sounds then reattache the water trap.
at this point you should have an audible,3 bars flashing and the oil transfer pump on.
the engine tank should refill and shutoff in 180 seconds or less.
anything longer than 180 seconds means there is either a restriction or low transfer pump voltage.


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