gauges

[flounderpounder225]

Sorry about that ,it's a 92 Yamaha 200 hp . It starts and runs mint , but then sometimes when you are going faster it will basically cut back to an idle while still going ?

Yep, sounds like fuel starvation, could be lines collapsing from being old and softened, could be sucking air occasionally, could be a fuel pump diaphram failure.  Have you replaced your under the cowling filter on the side of the engine? and your Fuel/water seperator filter?  Filters and clamps is where I would go first, and inspect the condition of all the fuel line you can get your hands on, bend it, squeeze it etc... if it's hard, dry rotting, checking etc... replace.  I would probably replace it all anyway for good measure, its not very hard to do.

[stuart725]

I have peplaced both filters , i'm going to replace both fuel pumps this weekend and then the fuel line soon after . Hoping that is the issue , if not then i will have the carbs cleaned  

[Capt. Bob]

I have peplaced both filters , i'm going to replace both fuel pumps this weekend and then the fuel line soon after . Hoping that is the issue , if not then i will have the carbs cleaned  

Still waiting for that pic but.....

Kinda sounds like the engine is overheating at higher RPM. This will cause the system to reduce engine speed until it cools to the proper operating temp. You get a warning light on the gauge under the little thermometer icon but then... your gauge(s) don't work.
You should also have an alarm horn sound but again.....

If the condition continues the next time out, I'd look at three things.
1. Change the impeller (water pump)
2. Thermostats
3. Pressure relief valve (poppet)

If it is heat related, one or both of the sensors that trigger the alarm could also be faulty.

My 91 200hp Yammy (pretty much the same as yours I'd bet) did exactly the same thing.

I'm not sayin' it's not fuel related but from your description it matches my former problem and if fuel isn't the issue, here's another place to look.

Good luck.

PS.... To me, both gauges not working would be a flag even with the historical failure problems of the LCD readouts. If I understand your original post, the gauges worked the last time you used the boat (then placed in storage ) and when you used it again, both gauges now don't work? Is this correct?

EDIT: Re-read your posts 13 & 15 and it sure sounds like an overheat condition to me. Cruisin' along at say 4500RPM (for example), then motor drops in speed to 1000 RPM (you wrote idle), continues at this speed for a while (never stalls or quits) then you can get back to cruisin' again. Does this sound correct or I'm I totally misreading your posts?

[flounderpounder225]

I have peplaced both filters , i'm going to replace both fuel pumps this weekend and then the fuel line soon after . Hoping that is the issue , if not then i will have the carbs cleaned  

Still waiting for that pic but.....

Kinda sounds like the engine is overheating at higher RPM. This will cause the system to reduce engine speed until it cools to the proper operating temp. You get a warning light on the gauge under the little thermometer icon but then... your gauge(s) don't work.
You should also have an alarm horn sound but again.....

If the condition continues the next time out, I'd look at three things.
1. Change the impeller (water pump)
2. Thermostats
3. Pressure relief valve (poppet)

If it is heat related, one or both of the sensors that trigger the alarm could also be faulty.

My 91 200hp Yammy (pretty much the same as yours I'd bet) did exactly the same thing.

I'm not sayin' it's not fuel related but from your description it matches my former problem and if fuel isn't the issue, here's another place to look.

Good luck.

PS.... To me, both gauges not working would be a flag even with the known failure of the LCD readout. If I understand your original post, the gauges worked the last time you used the boat (then placed in storage ) and when you used it again, both gauges now don't work? Is this correct?

Good point, its easy enough to put ground and power on the guages to see if they display...

[John Jones]

Good point, its easy enough to put ground and power on the guages to see if they display...

= mandatory before spending any money

[seabob4]

When checking for voltage on Yam gauges, you should have 12V+ on the yellow wire when the key is in the run position...

[Capt. Bob]

When checking for voltage on Yam gauges, you should have 12V+ on the yellow wire when the key is in the run position...

+1
Thanks SB.

Stewart,
What you've done so far is good time and money spent as far as regular maintenance goes but...
Before you tear into those carbs, I'd pop off the covers in the cabin and run a field equipment check on the electrical connections as Bob has stated.
It will only cost you your time but could save you even more time in the long run, not to mention the savings on new gauges.

I'm just sayin'

Good luck.

[stuart725]

First i bought the boat in december of last year and before that it wasn't used for a year and a half . The gas was emptied out and fresh gas put in and stable too .I did replace the water pump and that works fine (you can see the water peeing out the side of the motor ).  The boat is in great shape and looks like it was well kept . I'm going to try checking the wires , and then putting wires striaght to the gauges before i buy new ones . How hard is it to replace the thermostate and pressure relife valve and do you think it's worth my time to replace them anway ? :safe:

[Capt. Bob]

I did replace the water pump and that works fine (you can see the water peeing out the side of the motor ).

That's a good sign that your impeller is spinning around but not a definitive that it's working at its best. I say that because mine pissed out well also but still overheated. That stated, your pump may be fine and since you have replaced it, I would next look at the T-stats and pressure relief valve.

How hard is it to replace the thermostate and pressure relife valve and do you think it's worth my time to replace them anway ? :safe:

The work itself is not hard if you can spin a wrench. It appears that you are comfortable doing this so......
Yes, it is really worth your time to replace these items and for many "gearheads" it is SOP whenever they replace the impeller and there are a few that advocate yearly replacement. Complete flushing of the motor after saltwater use will extend the life of these parts but still, your motor is almost 20 years old. It appears you do not know when they were last (if at all) replaced so now is the time. You will also find that Yamaha has updated the pressure relief valve used in our older model motors to help reduce clogging of same. Mine had a fair amount of crap in the valve and I also replaced the hose/fittings.

My impeller looked in excellent shape when I replaced it, the T-stats were opening (you could/can see this when flushing) and there was a strong stream of water exiting the pee hole. Still, my motor overheated when run at higher RPM. If I had to guess just what the cause was now, I'd say the relief valve but rather than play "remove and replace" one part at a time, I did all three at once. Personally I feel it's just regular preventive maintenance concerning these parts. Costs are very minimal and I work cheap.

Lastly, the possibility of the temperature sensors (2) being faulty does exist but I would go the route above before dealing with them. They are a higher cost item for replacement and at least on my motor, appear to continue to work as designed. They can be checked (you do have a service manual?) as outline in the manual so it's not just a wild guess.

Good luck.

[stuart725]

thanks for the info i will be replacing the t-state and pressure relief valve as soon as i order them . Going to pull the boat tomorrow and bring home , but as soon as the parts come in i will replace and put in the lake near my house and fly around the lake for a while to see if that helped before i winterize the boat . That's going to be a sad day . :cry:

[seabob4]

thanks for the info i will be replacing the t-state and pressure relief valve as soon as i order them . Going to pull the boat tomorrow and bring home , but as soon as the parts come in i will replace and put in the lake near my house and fly around the lake for a while to see if that helped before i winterize the boat . That's going to be a sad day . :cry:

What's that???  

[flounderpounder225]

thanks for the info i will be replacing the t-state and pressure relief valve as soon as i order them . Going to pull the boat tomorrow and bring home , but as soon as the parts come in i will replace and put in the lake near my house and fly around the lake for a while to see if that helped before i winterize the boat . That's going to be a sad day . :cry:

What's that???  

Feeling a little antagonistic Bob??  

[seabob4]

Nah, Marc, just like to have a little fun at our northern brethren's expense...