Help! Twin 1990 200 Yamaha's

[reelly1]

I am helping someone with a pair of 1990 200 hp Yamaha's. And we have two seperate problems.<br /><br />The starboard motor acts as if it goes into slow mode intermitently. It will fall from 5100 rpms down to around 3000. Sometimes with a solid buzzer and sometimes no buzzer. Motor doesnt seem to be running hot. It does it so speradic it is hard to troubleshoot. BTW once you back off and idle a second you can take right back off and it may run fine for 15 20 minutes before it does it again. <br /><br />The port motor is not filling up the oil resevoir. The owner has already replaced the oil cap including the float. You can manually fill it up with the switch on the side of computer so I know the oil pump works plus it comes on momentarily when key is turned to start position.<br /><br />To rule out computers we have switched between motors and the problems remain on the same motor.<br /><br />Any ideas?

 

[jk1162]

Re: Help! Twin 1990 200 Yamaha's

there is a tilt switch built into the manual oil switch box control unit. it can actualy cause both problems you are speaking of. switch both with each other and see if you have the same problem with opposit engines.

 

[rodbolt]

Re: Help! Twin 1990 200 Yamaha's

have you replaced the remote oil tank filters latly? it will cause a slow oil transfer if clogged. that will cause a momentary alarm. by the time ya slow down and look its refilled the oil tank and it wont occur again for 20 or 30 min at wot.

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

jk1162, Thanks I will check it out.<br />Rodbolt, The oil filters were changed in the spring. If you take the cowl off and watch the tank it does not fill up at all. If you flip the manual switch it will fill back up in a matter of a minute or so. I will recheck the oil filters though. Any other ideas? Thanks again.

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

jk1162, Thanks I will check it out.<br />Rodbolt, The oil filters were changed in the spring. If you take the cowl off and watch the tank it does not fill up at all. If you flip the manual switch it will fill back up in a matter of a minute or so. I will recheck the oil filters though. Any other ideas? Thanks again.

 

[rodbolt]

Re: Help! Twin 1990 200 Yamaha's

do the trim gauges work?

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

Well he has no trim gauges. He has only the smart gauges that he installed on the boat last year. I know they didnt make those in 90 did they? ARe they compatible with those engines. They seem to work ok. However there is only a buzzer when it goes off those gauges do not tell ya if it is overheat low oil or whatever so i guess they work for rpms and fuel and that is about it uh?

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

out of curiousity where were you going with that. Is the trim gauge controlled by the same unit as oil pump? Thanks again

 

[rodbolt]

Re: Help! Twin 1990 200 Yamaha's

no but if it was rigged with the correct parts trouble shooting is easy. but as it was rigged with hodge podge BS its gonna be fun. if the trim senders fail the gauge wont work and niether will the oil transfer. so if ya jump onboard and the gauges show full up then ya know where to look. now you will have to manually test the trim senders with an ohmeter. if there is an open circuit it will inhibit oil transfer. its desined to prevent oil transfer with the engine tilted. also with the correct rigging you would see a visual indicate for the alarm. thats why if they dont wish to rig it right I send it down the street and wont work on them. it sounds like an oil transfer problem but without the visual its hard to tell.

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

Thanks that is where I will start on that motor. Any ideas where to start on the starboard that just goes into slow every so often. The oil tank on that motor stays full and it is not overheating. But a sloid buzzer sometimes when it does go into slow.

 

[Ray Neudecker]

Re: Help! Twin 1990 200 Yamaha's

Another rigging check to be sure the systems have all been rigged to the correct motor and no oil alarm wiring for example hooked to the wrong power head.

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

Thanks Ray and Rodbolt. Rodbolt ther are not even any semsors on the engines and no tilt swithces either. He has owned the boat for about a year a now and has already replaced one computer. He says that the gauges that are on the boat came with that model motor Is that possible that they made those smart gauges like that for 90 or 91 model motors? Still cant figure out what make the oil pumps quite other than One computer got fried for reason and the when he changed computers to see if that was the problem he fried that on has well. I geuss I will start with charging system and batteries. What does Yamaha recommend? Two Batteries per engine in a twin application like this?

 

[rodbolt]

Re: Help! Twin 1990 200 Yamaha's

I was not aware yamaha ever made smart gauges.<br /> are they the yamaha digital? the trim senders are mounted on the inside stbd transom bracket. the wire colors are orange,black and pink. your going to have to have a service manual for testing. and Ray is correct<br /> would not be the first set of twins I have seen rigged so the remote tanks were triggered from the wrong engine. and just cause its been that way a year does not mean it been right.<br /> this I see all the time.<br /> when you say computers, does the motors have the small black control boxes just under the engine tanks or the large computer with the emergency switch mounted on the exhaust plate between the cyl banks. one battery per engine is sufficent. I do like using on off switches and wire them so not only can each engine be run off either battery but the batteries can be parraleled as well.

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

Yea Digital gauges I am sorry I was just refering to them as smart gauges I guess they are just digital gauges. The control unit(computer as I have been calling it) Is mounted on the exhaust plate between banks. The emergency switch is mounted on the bracket that the control unit mounts inside of, the switch is not built in this unit. Each time you turn the key on the pump still comes for a second or two and comes on to the corresponding tank. In other words when you turn the port key on you can hear the port oil pump come on. And I am assuming (we know the definition of that) but when you manually press the switch it fills up that tank so I think the tanks may be right but wouldnt bet my life on it. I will check that as well. Thanks again any ideas on te control unit?

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

By the way. How is the Dolphin and wahoo fishing up this year in that neck of the woods? Went tuna fishing out of Oregon Inlet this year and did pretty good.

 

[Ray Neudecker]

Re: Help! Twin 1990 200 Yamaha's

The right hand side of that guage should be the trim indicator Rodbolt is asking about. A full up indication would be with all of the bars blacked out.

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

OK gotcha I did see that they were solid black. I will check inot that this am. Cool may be on to something thanks rod and ray!

 

[reelly1]

Re: Help! Twin 1990 200 Yamaha's

Ok I checked out trim sensors and there are none on these motors. Asked my buddy and he said that they were never put on there after a rebuild and the gauges on the dash have always said full up. Coming out of the control unit which wires should go to the oil pump? And if the control unit isc still good whatelse would stop it from pumping? Sorry but i want to mak esure before he buys a new control unit.

 

[Ray Neudecker]

Re: Help! Twin 1990 200 Yamaha's

The least likely suspect is the control unit. Very low failure item. An impoperly installed or defective sensor in the engine mounted oil tank is the most likely cause. Being sure the wiring harnesses are correct is the first place to start. If the control unit gets wrong information,it won't work properly. Not sure how it is working without the trim sensor being hooked up. Not supposed to.

 

[jk1162]

Re: Help! Twin 1990 200 Yamaha's

there is a tilt switch sensor built into the manual oil feed switch. if it is bad, it thinks the motor is tilted up and will not let the oil pump, pump oil to the tank automaticaly.