power loss

[BlazinNow]

Hey guys,

I fished a tournament saturday and noticed something funny. I'll start off by saying it was freezing cold and my boat stayed outside overnight. Got launched in the morning and it was 10 degrees. It was so cold my hot foot wouldnt return on its own after giving it throttle, i had to pull it back with my foot. So we blast off and Im going full speed across the lake, 6,000 rpm's then it drops to 5600 rpm's or so and i lose 4 or 5 miles an hour. Then it comes back up to 6000 after a minute or two, then back down to 5600. I made a 30 mile run and it did that most of the way. After the first run it never did it again. It's a 2003 Yamaha 250 ox66 with phase 2 kit. Any ideas? Also, It smokes embarrassingly bad when i start it up, not just in the morning but any time i start it. I run Amsoil synthetic. I adjusted my oil linkage to specs, just wondering if it could need a decarb or 02 sensor cleaning? Sorry for the long post. Thanks guys

[DChamp]

I put a PH II kit in my motor and Matt recommened staying with Yamaha oil for the motor. I also run Ring free and Stabill every time I fuel up. You may try a Ring Free shock treatment. I set my oil linkage at .013

[Mat_HT]

It sounds like the o2 sensor needs cleaning. Thats what they will typically do - drop rpm's at WOT - when they get carboned up.

[BlazinNow]

Thanks guys

[55excl]

How do you clean the O2 sensor?

[Terry M]

My 01 225 OX66 did that and they said the diaphram in one of the fuel pumps was broke so they replaced the fuel pump and also cleaned the 02 sensor, fixed it right up!

[craigs06]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 55excl &raquo;</TD></TR><TR><TD CLASS="quote">How do you clean the O2 sensor?</TD></TR></TABLE>

Here ya go

http://www.bbcboards.net...-hind

[55excl]

Thank You.

[hooken203]

What I have found on mine when it does that RPM drop due to the O2 sensor is that if I get clear out of the throttle and then right back at it it will clear.Make sure you check all three fuel pumps easy to do and also easy to replace. There is a reason that hydro tec recomends yamaha oil. TCW3 rating