1984 Yamaha 175 220aeto

[curjones]

Just bought this motor on on a skeeter boat. Having trouble on acceleration dies. If I get it to go over the trouble spot and try a hole shot the rpm is limited to 2000 and the nose stays up. If some one goes to the front of boat it will plane off and runs like a champion. One morning I was not full of fuel and it ran great got a decent hole shot. question one . Is there a rpm limiter safe mode on this motor.Question two. Can the oil controller inject too much oil. Does it pump oil from a rodon the cam or does it operate off of vacuum. Three. The miss or hesitation is bad at low speed in gear,real bad when trying to load on trailer often dies.

 

[cpj]

Re: 1984 Yamaha 175 220aeto

answers to your questions.<br />1.yes.if the oil tank on the motor gets low it will limit rpm to around 2000 .<br />2.anythings possible, but I would lean more to the pump not pumping enough.<br />3.two stroke motors do not have cams.the pump is connected to the the crankshaft via a small drive shaft.the fuel pump does "kinda" work off of vacuum, actually crankcase pressure.<br />I am having a simalar problem with mine .cleaned carbs,new filter,new lines, new fuel pump, going to go out today and try again.last week It wouldnt get above 1600 rpm.drove that way for about a mile, then all the sudden it came alive and ran fine the rest of the day.who knows.<br />p.s. dumb question but how do you have the trim set when you try to take off?

 

[curjones]

Re: 1984 Yamaha 175 220aeto

That helps. I took the fuel pumps apart to check the diaphrams. Found rust around the screws inside I cleaned that out and plan to get new pumps after the holiday. What did you use to clean your carbs with, spray or did you disassemble. Do you use any fuel additiave that helps keep the carbs clean. I start with the trim all the way down I've played with its position on hole shot in the down range area didn't make much difference. I dont have an adjustable jack plate either. When the weight of fuel goes down I get a better hole shot. question? When you are trying to hole shot does your RPM'S stay around 2000 ? or do they increase.<br />Do you have what I call a whale tail on the lower unit to give you a better holeshot

 

[cpj]

Re: 1984 Yamaha 175 220aeto

I use berrymans carb cleaner. You MUST disassemble your carbs to clean them.sray in every hole and blow them out with compressed air.I dont use fuel additives,Im not sure that they work all that great.I really dont know what my rpms are because I start from idle then the rpms rise to whatever I want them to be up to a max of around 5200 rpm.I have a whale tail and it doesnt make alot of difference on my boat(1985 challenger bass boat) I just tried it last week without it,and I lost 2 miles per hour with it off.It will get on plane about the same with or with out it as long as you give it full throtle.Now, if I am dinking around and ease into it,it seemed to plane quicker with the tail.It might handle a little better with the tail on, but I probably wouldnt use one if I had my choice.My boat already had one when I got it so.....

 

[Ray Neudecker]

Re: 1984 Yamaha 175 220aeto

If that is really a 220, you must run premium fuel or the knock sensor will cut the timing back.

 

[curjones]

Re: 1984 Yamaha 175 220aeto

ray,the motor plate has these numbers 220aeto<br />6g7-l then serial #. Where would th knock sensor be?. I have found this site to be very helpfull.<br />I ordered a manual but need to ask a bunch of questions for now. I found out that my warning buzzer works by putting the temp sensor leads together. What is the other sensor at the bottom of the head 2 wires metal nut.

 

[Ray Neudecker]

Re: 1984 Yamaha 175 220aeto

That is the knock sensor and it is a 220 which requires premium fuel to keep the engine from detonating and going into the safe mode.

 

[curjones]

Re: 1984 Yamaha 175 220aeto

Thanks Ray, Had it out on lake yesterday. Still having problems with the low throttle position. I idle fine but when I put it in gear and try to gas even just a little it bogs and dies. I found that if I get it over the hump and hit the choke real quick it will rev up and hole shoot.

 

[Ray Neudecker]

Re: 1984 Yamaha 175 220aeto

That is a fuel restriction. Time to go through the fuel system from tank to carbs.