1990 Yamaha 225 stalls

[Jrzvike]

I have a 225 that runs fine for an hour or so (sometimes several hours). Idles fine, runs open fine, BUT at some point when you return to idle and engage the throttle, the engine will sputter, die and I cant start it again for hours (day). This motor has been to 4 different shops with consenus that carbs are bad. Carbs have been cleaned and refitted, plugs changed, fuel drained, refilled and stabilized with same results. Last shop said motor was repaired and they had run it for hour and a half with no problems. Took scouts out skiing and wham, same thing again. It never dies when running, only when starting from idle to increase speed. On board computer ($600) has been replaced.

 

[rodbolt]

Re: 1990 Yamaha 225 stalls

can we get a full model number?
look at the last post, all 115 posts on it, about a shop wanting to replace all 3 carbs.
unless you sank it, odds are slim all the carbs with only 2 moving parts, failed.

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls

It is a 225 ETLD model. Also should add it is intermittent. Some days it may run 2-3 hours without dying. There have been instances where as soon as I go to place it in gear at the dock it will die and not restart. Carbs have been rebuilt. Thanks RODBOLT.

 

[rodbolt]

Re: 1990 Yamaha 225 stalls

well at least you have a spare ECU.
however I dont wish to see you have a spare set of carbs as well.
has the TPS reference AND output voltages been monitored when it happens?
most merc-a-rude techs like to imediatly blame coils and CDI units but the yamaha units dont fail often like the merc-a-rude stuff.
the odds of 3 carb failures at the same time is about astronomical at best.
this argument to convince me that all 3 carbs can go from runnig well to all failed to running well again better be good.
myself I would be checking stator charge coil outputs and audible alarm circuits and the kill circuit.
but only test them when its failed, exept the audible. that needs to be tested monthly.
quick test is to simply pull the stop lanyard and crank the motor, horn works or the system is broke.

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls

RODBOLT, thanks for the info...will try it out tomorrow. I may be way off, but previous owner informed me that when the '90 225 idles, it idles utilizing 3cylinders, and then when you put it in gear and throttle, the other 3 cylinders kick in... Is there some type of relay or switching circuit involved in firing up the other 3 cylinders that could be bad?

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls

Kill switch/horn is working. Havent been able to get it in the water to induce another failure.

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls

I was able to get the boat in the water last weekend. Weather and/or work have not been cooperating. Anyway, motor runs like a champ. When I went to slow down and approached idle speeds, the throttle felt "soft" (I dont know how else to explain it). The motor died. I was able to restart it eventually and motor ran fine. Motor idled fine at dock for 15 minutes while I installed bunk board slicks on my trailer. Very intermittent problem, only occurring at idle. It is sometimes very difficult to start when it dies. I did have luck with starting fluid when it died at one time...

 

[SparkieBoat]

Re: 1990 Yamaha 225 stalls

do not use starter fluid..sounds like you need to clean your carbs to me..idle jet/s sound clogged

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls

Will starter fluid damage the motor?

 

[99yam40]

Re: 1990 Yamaha 225 stalls

It does not contain any lubricating oil in it
It would be best to use some premix fuel/oil in a spray bottle to spay into carbs

 

[SparkieBoat]

Re: 1990 Yamaha 225 stalls

Will starter fluid damage the motor?

YES it will

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls

The saga continues. Out on the river today and it stalled on me three times. Ran great wide open and at idle, but three times when i would go to throttle it would die. I would crank for a while with nothing firing. I would wait twenty minutes or so, crank it up and it would run great. It would die when I was in a no wake zone or idling slow to pick up a skier. But at other times, it would idle fine at slow/no wake speed. I didnt have any test equipment with me today. This is really starting to get frustrating. As stated earlier, carbs rebuilt/cleaned, new fuel water seperator filter, doesnt matter if I run off of onboard tank or portable fuel tank, I just dont know on this one...

 

[MID FL CAP]

Re: 1990 Yamaha 225 stalls

Just wondering,did you look at,or replace the fuel pumps?

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls

I have not replaced the fuel pumps...That may be the next logical step.

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls

Great tip. Thanks.

 

[Jrzvike]

Re: 1990 Yamaha 225 stalls - Additional troubleshooting performed

Re: 1990 Yamaha 225 stalls - Additional troubleshooting performed

Got to do a little troubleshooting today. Since the motor is only stalling when advancing throttle from idle, I took a look at the throttle position sensor. While performing the ohms check, I noticed that for the first 30-40 degrees of throttle travel, the ohms actually DROPPED a few ohms instead of increasing. Once the throttle plate hit the 30-40 degree position, then the ohms steadily increased from low 400s to 2.3k ohms. I thought the sensor was bad. When I looked at the throttle sensor while having someone else move the throttle, I noticed no movement at all on the sensor until they hit the 30-40 degree mark while advancing the throttle. The minimal drop in ohms when initially throttling might explain the motor dying, but why does it not start for another 20 minutes or so? Also, is there an adjustment on the throttle lilnkage or cable that will allow me to get rid of the "dead travel" when initially getting under way with the throttle. It also explains how i was able to keep it from dying if it felt like it was going to die, I would shove the throttle forward and it would sputter and then take off. This may be simple math to you, but it is trigonometry for me.