2000 Yamaha ox66 200 idles for a while then dies

03svtsnakevert

Recruit
Joined
Jan 3, 2016
Messages
2
I just recently started having this issue. I took the boat out on Saturday and upon start up I noted that it smoked kinda heavy...however, it seemed to settle down... As I was idling out of the canal and had been idling for about 10 minutes, the engine stumbles and shuts off. Upon trying to restart it would turn over, try to fire and immediately die...if I let it set for a little while it would start back up....I was able to run it up and down the lake at speed with no problems, but the moment I started idling it would die and go through the hard starting or not at all....I would have to let it set like it was flooded or something...I also heard an audible alarm when I would try and restart the boat...no lights, just the audible horn...today I checked the LP by unbolting them from the block and pumping the bulb. I noted that I could pump the bulb and see fuel enter the filter and fill up and the bulb would get firm...after awhile I would have to pump it up again...when I got it started I pumped the bulb to see if the RPM would change and it did not. When I got it started today I let it idle for awhile and about the same time as the day prior it died and would not start...then it would just turn over and not try to start...I have been trying to read up on this but it seems that everyone points in 500 different directions...I have checked the oil sensor in the tank and it checked out...I checked the vst for flooding according to the manual, but I am not sure I pulled the vent tube when I checked it..


Looking for some insight here and I will answer any questions you gurus have to give you as much info as I can to help me diagnose and solve this.

Thanks!​​
 

tommarvin

Ensign
Joined
Nov 22, 2015
Messages
999
Do you have a computer on your motor ? If so borrow a laptop,get the software and cable, and diagnose the problem.

Whats the audible alarm for, overheat ? Find out what its for.

I just read a post about this,when coils get old and hot and start going out like this, test all ignition parts
 

03svtsnakevert

Recruit
Joined
Jan 3, 2016
Messages
2
Do you have a computer on your motor ? If so borrow a laptop,get the software and cable, and diagnose the problem.

Whats the audible alarm for, overheat ? Find out what its for.

I just read a post about this,when coils get old and hot and start going out like this, test all ignition parts

​Yeah, the ox 66 doesn't have the interface that you can hook up to a laptop and diagnose...you can only hook up the flasher to it and watch for the flashes to see if it has any trouble codes
 

yamatech43

Petty Officer 2nd Class
Joined
Feb 9, 2011
Messages
188
If it was a coil problem it would show at high rpm...from your post it runs fine just won't idle and then start when warm....I would first be wary of your alarm system, and so first I would let it go thru it's routine and leave cowling off...when it dies, reach back and put your hand on each top of cyl banks and you should be able to hold your hand on top for two or three seconds....but you have to do this right then, not twenty seconds later. You can easily have a water pump not doing it's thing at idle, but ok at speed and you may have an alarm issue, usually found out about when it fails to warn you like this....just a thought.
 

grid

Petty Officer 1st Class
Joined
Oct 29, 2002
Messages
232
This may or may not be your answer, but I had a job where the engine was doing the same thing. It ended up one of the low pressure fuel pumps was leaking fuel into the engine, flooding it out at idle, but at throttle, that hungry mama would suck all the fuel it could get, however it could get it. Back each fuel pump away from the block, one at a time, and squeeze the primer bulb. If you have fuel squirt out the back of the pump, there's your culprit. If it were I, I'd replace all 3 and be done.
 
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