On the 2008 Indmar 340 Monsoon engines there are only two pre-cat O2 sensors.  There are also a pair of exhaust temperature sensors in the post-cat down pipe, but they are not O2 sensor.  Curious why you are looking for them?

Does an 06 VLX have a HDS box? If so, it's prob cracked inside, causing the leak.

Do you have a dripless shaft seal, or packing? Either one might need maintenance to keep from leaking.

25 minutes ago, mobius481 said:

Thanks for the feedback.  I just can't imagine a scenario when I have 15 people in the boat.  It's just not how we use our boat.  I'm hoping I can use the standard prop as my daughter slaloms and every once in a while I like to barefoot.  But I'll probably get both props.  Do you run the wedge in lift mode at 30 mph?  I've heard conflicting info on what speed you can use lift mode.  From what I can tell, lift mode is fine at any speed but wedge below 24.  

I haven't done that yet but it's tempting.  It gives you a warning at 25 mph but I've seen other threads where people just ignore that.   When I free ski I'm just out having fun and getting exercise so I'm not too concerned with wake size.  I have a closed bow Nautique that sits at a private ski lake for more serious slalom.    Also noted that the 2024 23LSV is a tad heavier than my 2021 so that could make a little difference with the M5 vs M6 discussion.  

The M5 works well for us in a 23 LSV at about 1000 ft above sea level.  We'll put it more to the test this weekend with 10 people on the boat.  The first thing I did was ditch the high torque prop and went to the ACME 2805, which greatly reduced revs across the board and still gives me low 40s on the top end and doesn't have an issue with full ballast + PNP bags.  The 2:1 transmission in the newer boats is a game changer as is the 17" diameter propeller vs my "OG" boat before.  We run factory ballast + PNP bags in our boat.  Good luck with the new one!

42 minutes ago, skiyaker said:

we just picked up a 2021 23 LSV with M5.  Previous boat was a Moomba outback V.  That tiny thing ran like a scalded dog.  We boat mainly in Indiana and Tennessee close to sea level.  Here's my take

screen- no issues so far but time will tell

M5- plenty fine at sea level with 3 to 6 people.  No problem holding speed for surf and wakeboard with full ballast including PNP, and it can pull me slalom at 30 mph no problem.  We have whatever the "high torque factory prop" is.  When we loaded it up with 15 people for my son's after graduation party with full ballast she was a bit sluggish out of the hole and I wanted the M6.  But for our normal size crew the M5 is adequate... not excessive but adequate.

stereo-  stock stereo with sub and two rev 10s- loud as hell and great clarity.  They can hear Mr. Brownstone at the boat ramp when I'm about a mile away.  Can't imagine wanting more sound out of it but that's just me.

Thanks for the feedback.  I just can't imagine a scenario when I have 15 people in the boat.  It's just not how we use our boat.  I'm hoping I can use the standard prop as my daughter slaloms and every once in a while I like to barefoot.  But I'll probably get both props.  Do you run the wedge in lift mode at 30 mph?  I've heard conflicting info on what speed you can use lift mode.  From what I can tell, lift mode is fine at any speed but wedge below 24.  

3 minutes ago, klntime said:

m5 is fine at sea level in 23lsv, will handle lots of weight with right prop.  I run Full ballast, 500 extra pounds of lead, 6-8 people in boat, use lift to get on plane, no problem at wakeboard speed 22mph.  Surfing is a breeze too with same prop.  M5 effecting resale, not likely in 90% of cases.  Yes, the 1%'rs on forums like this will likely opt for an M6 and know the differences.  Most of your general boat buying folks have no clue or really care.   

Enjoy the new boat!

Where do you put the lead?  Thanks for your thoughts.