1999 200 yamaha vmax ox66 3.1 liter

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Barry2980

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Jul 28, 2009
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I have a 99 model 200 yamaha vmax and im having a problem with my motor. It will jump out of the whole shot and it was running a around 5400 rpms and now it only runs 4400 to 4600 rpms opened up and trimmed. and it sounds like it is flooded or something, i dont know how to explaing it. i have heard something about a o2 sensor needs to be changed could that be the case? i hope so and my compression is great all the way around. it has been using more gas than usual too. can someone please lead me the right way? i have ordered a new o2 sensor i figures i could start there. how do you change them anyways?
 
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Barry2980

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Re: 1999 200 yamaha vmax ox66 3.1 liter

also its not wanting to idle to good... sounds like it loading up or something
 
Islandbrah

Islandbrah

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Aug 14, 2009
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Re: 1999 200 yamaha vmax ox66 3.1 liter

The o2 sensor looks like a little hollow barbell on the starboard side up high. open the cover with the warning sticker on it. The casing is held on by a couple of 10mm bolts after the cover is removed there is another finned cover to take off with i think 3 10mm bolts. inside the passage is the little barbell o2 sensor. mine was covered in carbon chunks . Cleaned it with carb cleaner and replaced. No need to buy a new one.
 
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Barry2980

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Re: 1999 200 yamaha vmax ox66 3.1 liter

well i bought a new one because i dont think it has never been changed. i hope it fixes it.
 
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rodbolt

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Re: 1999 200 yamaha vmax ox66 3.1 liter

sounds like you blew a lift pump diaphram, could also be a clogged regulator filter creating excess fuel pressure or a clogged VST filter.
 
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Barry2980

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Re: 1999 200 yamaha vmax ox66 3.1 liter

i have two new lift pumps, where is the vst filter located and where is the reg filter located? i saw where i guy a while back ago had the same problem as me and it ended up being the o2 sensor, i hope it is because i have bought one and going to change it tomorrow after work. thanks for your time.
 
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Barry2980

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Re: 1999 200 yamaha vmax ox66 3.1 liter

just wanted to let you all know, i bought a new o2 sensor $360.00 and installed it used the proper steps and cleaned the slot out that had chunks of carbon build up out and took it to the water and it ran great. im glad that fixed it as of now.
 
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