04 Yamaha 200 OX66-Problem - The Hull Truth

txtightline · 06-16-2008, 11:34 AM

Have a 04 200 yammie OX66 with about 200 hours. Has been running great, no problems.

Recently, after running for more than 5 minutes or so at RPMs of 4500 to 5000 it will "sputter" or even stall out for a few seconds. If I back off the throttle and then bring it back up, no problem. Run for a few more minutes and happen again...sometimes it happens sometimes not. Running below 4000 RPMs no problem.

Seems like a fuel issue to me...possibly clogged filters?

Checked the water seperator and its good.

Any suggestions?

slapshot · 06-16-2008, 02:36 PM

VST filter needs to be cleaned or replaced. Here's some info on it.

http://bbcboards.zeroforum.com/zerothread?id=66928

rwstoney · 06-17-2008, 06:53 AM

Clean the very very fine filter screen on the bottom of the high pressure fuel pump. This has happened to me every year for three years. The filter on the bottom of the pump cleans up nicely with spray gumout. I suggect buying a new o ring for the vst tank. While you have it apart clean the filter in the pressure reducing valve. This site has parts at reasonable prices with good diagrams you can download.
http://www.boats.net/parts/search/Ya...ard/parts.html

John_Madison CT · 06-18-2008, 05:13 AM

Agreed, clean or replace (I prefer replace) your VST filter. When was the last time you did your low pressure pumps and cleaned/tested your O2 sensor??

bbogue · 06-18-2008, 06:34 AM

Great advice on this and other repairs can be had from Andy at SIM on the vendor boards. His prices are very competitive with boats.net. Andy is the Yamaha man IMHO.

Bill

El_Guapo · 09-30-2010, 02:21 PM

I have the same problem . Could anyone walk me through. how to test the o2 sensor, and how to replace the VST filter?

jkroth · 09-30-2010, 02:35 PM

scroll down to the post from signmansez, I found it helpful

http://www.thehulltruth.com/shipyard...or-filter.html

sako300 · 09-30-2010, 03:15 PM

mine did the same thing. problem was low pressure fuel pumps. 3 small fuel pumps right next to the vst tank. about 140 bucks for all three. hope this helps

Striperswiper12 · 09-30-2010, 03:41 PM

See my reply to El Guapo above
Although you might not have the 3 mechanical pumps on your engine. I don't know when the switched but they now have a electric pump for low pressure.

lostsinker · 10-01-2010, 05:33 AM

Don't bother with the O2 sensor, that's not your problem.

You didn't mention if the primer bulb collapses when the engine acts up.
Although a clogged VST screen could be the issue, the symptom usually shows up at lower RPM.
You said you checked the water separator. What does that mean? When did you last change the filter? Has the engine mounted filter been changed?