Ox66 O2 sensor draw tubes - rodbolt?

[fondafj]

I've been crawling through both of my '99 225's to make sure they are maintained as they should be. Recently cleaned the O2 sensors and they still tested bad. When replacing the sensors and re-cleaning the sensor mount and draw tubes ---- I found the draw tubes had wear as if they were moving in the cavity. Is this a common problem? Will this affect the O2 sensor operation?? <br />Thanks for the advice so far

 

[bigbrownbuku]

Re: Ox66 O2 sensor draw tubes - rodbolt?

cant say ive ever noticed wear on the draw tubes?<br />they are a fairly cheap part for the peace of mind. what did you clean your o2 sensors with?<br />also check your plug lead caps are in the 4-6k range. another common fault thatll cause some poor running.

 

[fondafj]

Re: Ox66 O2 sensor draw tubes - rodbolt?

BenC,<br /> I cleaned the sensors with Yamaha decarbon using the info from this forum. There is a slight ticking coming from the O2 area at idle and I wonder if it is the draw tubes moving. (although I haven't checked since installing the new gaskets).In an earlier post I had described the meter readings after the clean --- they were too stable and the swing by plugging the #1 cyl bleed hole went from 0.54V to 0.59V and back to 0.53V. Rodbolt seemd to think the sensors were bad and since I don't have the cleaning history (other than the once I cleaned them), I purchased and installed new ones... although I have not re-performed the same test on the new ones. I have a trip coming up where we will be doing some extended running over 4500 rpm and I didn't want to risk a lean run condition.<br />Overall both engines ran fairly well - one had some problems starting while hot. The other surged occasionally. So far here is what I have done this year:<br />- Plug lead caps - found 6 of the 12 bad. Replaced the bad ones<br />- Poppet valve grommets replaced - found one plunger installed backwards<br />- Thermostats tested for correct opening range<br />- New low pressure fuel pumps - all but 2 looked to be original<br />- Found a slight kink in the fuel line on one engine<br />- Found cracked oil pump clip - replaced both<br />- New VST filters, fuel filter and water sep filters<br />- New O2 sensors<br />- Lower unit oil<br />- Water pumps were done last fall<br />- Removed 2 anodes from head - both looked like new<br /><br />I will order 2 draw tubes and install them. Like you said --- cheap peace of mind. Thanks

 

[bigbrownbuku]

Re: Ox66 O2 sensor draw tubes - rodbolt?

have both your tps sensors checked. also check the sight tube in the bottom of your engine oil tank for debris and you have about covered it all.<br />the rest you can see in your crystal ball.

 

[fondafj]

Re: Ox66 O2 sensor draw tubes - rodbolt?

BenC,<br /> I have not checked the oil tank sight tube but will check tonight. Checking the TPS was in my plan but I didn't get to it yet ---> non engine related boat work had me distracted. I believe the manual spells the test out clearly... I'll bring my manual along on the trip and check it dockside one evening. <br />Thanks for the advice.

 

[rodbolt]

Re: Ox66 O2 sensor draw tubes - rodbolt?

yes<br /> if the draw tubes clog they will knock just like a wristpin. if the ends are shiny they have been moving some. as long as the tube is clear it does not appear to hurt anything. ask your yam dealer to look up the bulliten on the updated draw tubes for the 3.1L engines( if yours is a 3.1) to see if its applicable.

 

[fondafj]

Re: Ox66 O2 sensor draw tubes - rodbolt?

Rodbolt,<br /> Thanks for the info --- I will contact the dealer.