2004 Yamaha 225 ox66

[Dc209]

I have a 04 225 Yamaha V max runs like a champ, I was making a long run last weekend after about 10 miles or so it started loosing rpm went from 5800 down to 4200, I let off the throttle and floored it and it jumped back up to 5800 and then dropped back down to 4200 I backed off the throttle to about half throttle and it started climbing back up to 5800, I stopped fished a while moved spots it ran great for a little while and done the same thing

[1ranger487vs]

Sounds like a o2 sensor. Clean the tunnel and replace the sensor. I think it’s ntk21006 but I’ll check

[1ranger487vs]

Yep ntk 21006. About 35 bucks on eBay. If you don’t run ringfree ever tank. Search this site for easy way to wire it

[Dc209]

Thank you 1ranger487vs I cleaned it once but I will replace it this time

[201pro]

They don’t clean and work properly. Even tho the manual says you can.
The NTK replacement will make a big diff.

[Dc209]

Thanks 201pro

[Dc209]

Could the TPS cause this problem or if it were bad would it not read at all

[javelin90]

While you are replacing the O2 sensor go ahead and splice in the harness making it quick and easy to replace the O2 sensor. Make sure you clean the barbell inside the tube. Also use a Qtip to remove any carbon residue inside that same tube.

[Dc209]

Thanks javelin90

[wcs69rat]

Mine was doing the exact same thing. I did the O2 sensor mod using the NGK / NTK 21006 O2 sensor like the above responses said to do. For $35, order two so you have a spare. If you need the pigtail for it, google LS1 O2 sensor harness.

[Dc209]

Thanks wcs69rat I ordered one from amazon for 28 bucks should be here tomorrow I will keep yall posted if it works thanks for the advice