Yamaha V6 oil pump or sensor sticking?

It happened for the first time this weekend. I don't know what would be the most likely or maybe yamies are known for this but here goes.<br />I start my motor and after a few minutes I get a Temp/low oil alarm. I took the cover offteh motor and the reservour was very low. I turn the motor off. I start it again and the reservour slowly fills until it is full. The motor runs fine all morning long. I start it later to head home and the same scenario, the tank empties until I get an alarm and the engine reduces speed. I bring it down to an idle and start to 'limp' home, I pull the cover to see that the reservour filled itself. I turn off the motor, restart it and alarm is gone and I am fine all the way home.<br />My question: Is it more likely that the sensor (float) is hanging up in the reservour OR is my oil pump in the Remote tank running intermitant? <br />Is the sensor in the reservour, that tells the remote pump that it is full, the same as the one that tells the engine to idle down? I'm hoping after many years, the sensor is just a bit gummed up.

Re: Yamaha V6 oil pump or sensor sticking?

How many hoses go to remote pump? Carbuator or injected engine.

Re: Yamaha V6 oil pump or sensor sticking?

1 Hose to the Remote pump. Carburatored.<br /><br />I think I got it. I took the sensor out of the engines oil tank and cleaned the shaft that the float switch rides up and down on. It was not smooth it had some crud on it. I took the remote tank out of the boat and kept zapping the pump with 12V. It ran fine every time. I'm hoping the sensor I cleaned was hanging up so there was no signal to the remote pump to pump oil up to the motor. We will see this weekend.

Re: Yamaha V6 oil pump or sensor sticking?

Message for Tony H #2555<br />Re: Yamaha oil pump\<br />I have a 28 Mako with twin Yamaha 250's; very low hours.<br />Port engine runs 20 min and gives alarm as you describe. manually fill oil tank on engine and engine is ok. have been looking at the pump but your solution sounds worth a look. Question is:<br />Is the sensor float on the oil tank under the black round rubber 'stopper' on top of the tank? Assume so; have given it a good 'tug' but not a real hard pull. Cannot find Y service for a 250 near to me. Get parts out of St. Petersburg.<br />Do you have any experience with low speed rough running but ok high speed (maybe gummed up low speed jets in carb)<br />Thanks in advance<br />Tom Wadsworth

Re: Yamaha V6 oil pump or sensor sticking?

Yes Tom, The Black stopper IS the float.<br />Wiggle it, it'll come, they are in there tight.<br /><br />This Float cleaning is the first step as far as a Cheap fix.<br />Disconnect the red wire and the connector, take it off. You can see how the barrel inside the plastic housing is supposed to ride up and down the brass shaft. Take the little clip off the bottom of the float, the bottom plastic will come out then the barrel shaped piece and plastic housing will all come off the brass shaft. Clean it all up and put it back together. Hope for the best.<br />If that doesn't do it then more then likely it's the module on the side of the motor that this module plugs into. The one with the emergency fill toggle switch. They will cause this exact scenerio. I hope it's a gummy float.<br />If you have a newer Yammy, I heard that this Module is all part of one big circuit brd...Very expensive.<br />Good luck

Re: Yamaha V6 oil pump or sensor sticking?

Tom as far as your low speed goes...Yes, sounds like jets.<br /><br />As scary as it looks, taking the Carbs off isn't bad at all. The linkage literally snaps off and if you don't mess with any adjusting screws, your carbs will stay synchronized. Don't mess with anything other then taking the Bowls off the bottom of each one, unscrew the jets and blast them clean put everything back. I have done this twice and the rubber O-Ring gaskets did not need replacing.<br />Just put the carbs back in the same position you took them out in (i.e. Top, Middle, Bottom)

Re: Yamaha V6 oil pump or sensor sticking?

Reply to Tony H<br />Many thanks<br />I will try all of this out in a few days and see what happens.<br />Glad to hear your comments re carburetors<br />The linkage is a bit daunting to look at.<br />Pretty sure it is low speed jets.<br />This boat spent several months on a ship from Singapore to Norfolk and has been sitting for 2 years; did manage new fuel about 6 months ago.<br />Thanks again<br />Tom Wadsworth

Re: Yamaha V6 oil pump or sensor sticking?

Sitting for two years...Absolutely the jets!<br />I screwed up my shoulder and let my boat sit for 1 season and that's when I had to do my carbs.<br />Too bad you don't live on Long Island (New York) I swing past and give you a hand. You could be all done in 1 to 2 hours.<br /><br />The oil issue, at least you can swap out one part at a time ( the float then the module)with the other engine and see if you get the alarm on the other engine, that will tell you which part is bad.

Re: Yamaha V6 oil pump or sensor sticking?

Finally got to boat; checked float on engine tank; OK - moving freely. Pulled oil tank and pump. This is the problem. When I pulled the motor for the pump apart, I found that one of the fields inside the housing was loose from its attachment (looked to be a kind of glue) to the side of the motor housing. The armature, brushed etc looked good. considering the trouble to get at this pump I am going to buy a new one.<br />Pulled one carb. Looks V. clean. no signs of any gunk, junk, dirt or other unwanteds.<br />All I have done is unscrew the two jets on the bottom of the float after you take the bowl off. Not sure which way to go now. Have managed to lose my Yamaha book so it will take a week to get another one. What is inside the shiny ss plate on the top side of the carburetor?<br />i may just put the oil pump in and try to run the boat for a few hours. It desperately needs to run. Runs ok on a plane - around 4600 is all - not the 5500 when tuned up but it needs running.<br />Thanks for your help.

Re: Yamaha V6 oil pump or sensor sticking?

for you guys messing wtih the oil tanks, change the little filter at the back of the oil tank as long as you have it out. Also make sure you dont have some bad oil that has gelled with some condensation or water which might be cloggin the system. depending on how old the oil is you might want to dum what you have and clean out the tank as well as the filter change. fill with clean new yamalube only. I ran 87 200's for a long time - finally got new 2002 200 HPDI's !!!