Engine is '98 225 Salt Water Series II V-6 TWO CYCLE. Has been running great most of the time. However when out fishing on a drift and I go to start after an hour or so, it idles down low to about 400 - 500 rpms and sometimes shuts down before I can get it in gear and get the rpms up. Very easy to start after it stalls. Once she's up to 700 or 800 it's fine, cruises all day and sounds sweet. Question - Is this plugs or a fuel filter issue? Thanks.
Yamaha Stalling
- Thread starter hotajax
- Start date
If it were mine I would do a decarb treatment. And add Ring Free 2oz per gallon then run it, if it's a carbon issue it will gradually run better. This is the cheapest and easiest thing to try first. Just my $.02, good luck with it.
I can't be sure but it could be a choke issue. After an hour of sitting the motor may have cooled off enough to need the choke function and if it does but the choke doesn't work, the motor will idle too low.
Do you have a manual choke feature at the ignition switch? I think the choke on that motor is electric using some sort of solenoid.
If the choke isn't working, either it is defective or the signal that tells it to engage is not working correctly. That may be tied to the engine temperature sensor.
All guesses at tis point.
Do you have a manual choke feature at the ignition switch? I think the choke on that motor is electric using some sort of solenoid.
If the choke isn't working, either it is defective or the signal that tells it to engage is not working correctly. That may be tied to the engine temperature sensor.
All guesses at tis point.
No chock to worry about on that engine since it's fuel injected.
Since it runs fine at higher RPMs, I'm guessing it's not a fuel issues. That being said, I would go ahead and replace all 3 low pressure pumps if it's never been done.
I would also check the O2 sensor, TPS and oil pump adjustment rod. I have procedures at home I can send you. PM me your email address. The TPS check requires a special harness.
Since it runs fine at higher RPMs, I'm guessing it's not a fuel issues. That being said, I would go ahead and replace all 3 low pressure pumps if it's never been done.
I would also check the O2 sensor, TPS and oil pump adjustment rod. I have procedures at home I can send you. PM me your email address. The TPS check requires a special harness.
Parthery
GreatGrady Captain
gw204 said:
Not all SWS motors are Fuel Injected (OX66)...I have a 98 150 SWS II that has carbs and it was doing the same thing. I think its a vapor lock type situation...I only had the problem in the dead of summer when the ambient temperature was close to 100 degrees. And when it did it, it was a challenge getting the motor restarted.
Now that its cooled off, ever so slightly, the problem seems to have gone away.
I assumed , perhaps incorectly, that it was carbed. It is probably not vapor lock since it starts but idles low and stalls
gw204 said:
I don't think its O2 since when it runs, it runs well. Usually if the O2 is malfunctioning, the motor runs richer.
TPS is possible but a malfunction should affect the motor at all times not just after running and then sitting.
Oil pump linkage if incorrect could result in fouled plugs but again that would be 'permanent' and that is also not how the problems are described. You would also see excessive smoke when restarted.
I would suggest pumping the primer bulb when restarting and seeing if that helps. If so, we have a fuel delivery issue.
Parthery
GreatGrady Captain
On the other hand...if one was to read the OP entire post, I would have noticed that its an OX66, not a carb'ed motor. My apologies to everyone who politely saw what I missed... :-|
That said, I'd go back to the low pressure fuel pumps and start there.....they aren't particularly expensive to replace....
That said, I'd go back to the low pressure fuel pumps and start there.....they aren't particularly expensive to replace....
oops. OK SX model.. I missed that.
It could be LP pumps but as mentioned, try pumping the primer bulb to see if that helps. If it does, we are looking at a fuel delivery issue. Also note that if it doesn't help, does the ball get firm or stay soft.
It could be LP pumps but as mentioned, try pumping the primer bulb to see if that helps. If it does, we are looking at a fuel delivery issue. Also note that if it doesn't help, does the ball get firm or stay soft.
seasick said:
Well, I hate to say this because it I don't want to be accused of using puns, but here goes. The boat sat for 2 months. I tried to squeeze the ball for 30 - 40 times and it never got hard, but it did start easily. Smoke was no more excessive than usual. I've never had to squeeze the ball before when I re-start after a drift. More on this in another thread. Thanks for the input.
gw204 said:
First, GW204, thanks for the input. I called Andy at SIM to ask his opinion, as I am reluctant to take the boat to a Yamaha shop and ask them to analyze it. That would be like giving the keys to the store away. Andy, like GW204, was under the impression that it is the LP pumps. He also suggested that it could be the VST was dirty. But, he did say that if the VST was dirty, I would be having problems all through the power range. The price for replacing the 3 LP pumps is not bad - certainly cheaper than most engine work. Just to review in case there are other opinions:
There is no evidence that the 3 pumps were ever replaced, as the previous owner's marina kept fairly good records;
Higher rpms runs fine;
Easy to start after it stalls out;
Smoke no worse than the day I bought it, and it ran fine;
Plugs probably have 40 hours or so, using Yamalube.
I do use Ring Free, so carbon is probably not an issue
Have not replaced the fuel filter, probably very inexpensive job to do.
Thanks for the opinions.
I had the same problem with my 150's and when I checked the float level, of the 12 floats, 8 of them were out of spec some by as much as 2 mm. After resetting all the floats the boat starts and idles fine in all weather conditions. BTW --- The floats are all goo and the settings were from the factory installation. The engines had never been worked on except normal maintenance.Parthery said:
Don't assume the carbs are "RIGHT" just because the factory did it.