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I wanted to know if any one could help. I have a 1999 250 yamaha ox66 that is running rough both at idle and at all different RPMs. I have cleaned the Fuel pump filter, changed the water separator (rakor) the bowl never had water. Changed the spark plugs, changed the spark plug boots, I have been using rec fuel for about 7 month now. it is running fine then it will sputter then pick up again then sputter on and off all the way from idle to 5400 RPM. Its not a hard drop but you feel it. Any help i would appreciate.
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could be anything from a clogged filter on the VST intake or return,clogged injector filter, poor ground.
not really enough information. -
I cleaned out the VST filter but I will check the ground wire. How do you check the fuel injector filters? Or do you just replace them. I have never checked or replaced them. what other information do you need?
Thanks for the replyComment
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if fuel pressures are staying in spec at all RPMs, and the srceens/filters needed cleaning/replacing the it is a good chance the injectors need to be pulled and sent off the be flow tested and cleaned.
You will get a report back on as found and as leftComment
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I have the same motor & had a rough idle, cleaned vst filter, new lift pumps,fuel lines, plugs & caps, still had a rough idle & hesitation on accel, had the injectors cleaned & what a world of difference, still need to take it out to see if top rpm's are back, water was to rough last trip out.Comment
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Thanks for the info. Are the injectors easy to remove and who would does this service ( cleaning the injectors)?Comment
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Injector flow test and clean.
Yeah, who is the recommended service provider and what would be an expected price and turn around time. Just a rough estimate...If its got teats or tires, you bound to have trouble with it....Comment
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The injectors are easy to take off, remove cover off throttle body, then the 4 bolts holding rail on, unclip the harness to each injector using a pick, the wire retainer on the harness does not have to come off. There is a local marine shop by my house that offers to clean them, $45 ea. & had them ready the next day.Comment
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Did a web search and found numerous offers. Price range 38 - 16 dollars each.
Note, did find a website that was at the lower end of the pricing range that was priced for flow testing only. I can see that after the test results are in, then they have a hostage and can charge whatever ransom they choose. If your going to websearch and choose a vendor, make sure that the price includes flow testing, ultrasonic cleaning, after testing, and new seals.
Also noted that they want the seals so they can replace them with same.
I'm more inclined to want my factory seals that are in good condition rather than new aftermarket stuff. Yamaha for Yamaha. I'll contact them and ensure that they return my factory seals and injector filters.If its got teats or tires, you bound to have trouble with it....Comment
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Well today we tested it for sparks and it would loose spark on and off while running in low and high RPMs on two each cylinder I know it runs on four in low RPMS but even in high speeds it would lose spark. replace the coil and still same thing. I am really stuck. now but atleast I know its losing spark could this be the computer.Any helpComment
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unless you have a VX model the S and SX 250 OX66 motors use CCS
at cranking all 6 spark.
running below about 600 RPM all 6 spark.
from about 600 RPM to about 2000 RPM #5 does not spark.
from about 850 to about 2000 RPM #2 does not spark.
in the event of a sensor or pulser coil failure CCS is disabled.
CCS is also disabled at engine temps below 113*F. code 33.
Vmax, not to be confused with V76, does NOT use CCS.
Vmax was the 20" bass boat version of the 3.1L OX66.Comment
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Well i finally got my mechanic to look at it and two coils were not sparking consistently wierd we had to take it out and run it, replace both coils and now shes running great. Thanks for all ur input. I will clean out the injectors sounds like a good idea.
Thanks againComment
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