OX66 manual questions

[andy6374]

I just picked up a boat with a 1998 OX66 250. Motor runs great and I want to keep it that way.

Since this seems to be a relatively simple motor to maintain, I figured I would do it mostly myself. So like all motors I've owned, the first thing I did was purchase a Yamaha Factory Manual (Service Manual # LIT-18616-01-85). Lets say I'm less than impressed with the manual.

Most of the things I've read on this site and others about maintenance procedures and periodic adjustments isn't in the manual.

For instance I can't find anywhere that the oil link rod stop should be against the stop (or 0.04-.08" off the stop) as I've seen Rodbolt post.

It says the o2 sensor minimum voltage is .3V but not that it should rapidly fluctuate between .3-.6V. Also it says nothing about cleaning the draw tube nor inspecting it.

And the description on how to perform other adjustments is rather poor. My mercury factory manuals were head and shoulders better.

At any rate, can someone recommend another manual. Perhaps the 2002 ox66 motor is very similar but the manual is much better?

 

[andy6374]

Re: OX66 manual questions

Do I have the correct manual?

Besides the number on the manual LIT-18616-01-85, the cover says

S225W
L225W
V225W
S250W
L250W

The copyright date is 1997 (my motor is a 98').

 

[nickmo]

Re: OX66 manual questions

Andy, I have a Clymer manual for my 1999 225 ox 66's. For me it was much easier to understand than a friends Yamaha manual. More pictures too.

 

[jeffersondodson561]

Re: OX66 manual questions

If you decarbon your motor regularly the chance of clogging the O2 tube is increased. Having seen the service manuals on the link rod there was a spec on the link rod but having talking to tech service they recommend that as long as the rod is touching the stop and not putting stress on the throttle valves you are ok. If your taking the O2 sensor out to clean you might want to clean the sensor itself with a propane torch you can hook a digital meter up to it to be sure that you dont over scorch it, just watch the meter and watch for increases in voltage and watch for the maximum voltage increase then take the flame away once you see maximum voltage, meter should be on milivolts and yes Yamaha manuals suck but the tech guides are gold if you can get your hands on them (all manuals are available on YMBS at your local yamaha dealer) if you can swing it.

 

[rodbolt]

Re: OX66 manual questions

the propane test is a teat on a boar hog.
its just to simple to CORRECTLY adjust the TPS,throttle shutters AND oil link rod clearence.
there are 3 tech bulitens pertaining to O2 sensor output voltage tests, the 4th is a flame test that is a teat on a boar hog.
if the engine block was replaced since about mid 2003 the O2 sensor holder and attaching parts are going to be different than your manual and the parts guide.
the oil link rod should NOT be touching the stop pin.
with the trottle shutters fully closed, not touching the shutter stop screw, you should have .005 to .020 clearence.
quick check, simply unclip the bottom 2 shutters from the throttle link arm and check it.
yes its an incredibly simple speed density EFI setup that kicks a lot of techs.
if you wish to PROPERLY maintain it your going to need 600 dollars or so worth of tools.
this will include a diagnostic test lamp, a decent digital volt meter, the DVA adapter for the meter, a fuel rail pressure guage and a few harness adapters.
other than that any questions pertaining to a manual procedure we can help you with.

 

[andy6374]

Re: OX66 manual questions

Rodbolt-

I already have a DVM with a DVA adapter. I planned on purchasing the other associated yammy harness this winter.

My biggest gripe, is the manual. Like i said (maybe I'm blind) but there is no single mention of how to adjust the oil link rod. Nor does it mention to clean the o2 sensor draw tube. It just seems like a lack luster manual, that's all.