Yamaha OX66 Low Idle Sneezing

General Boats and Motors
1

Has anyone figure out how to stop this. So far I have:

  1. Replaced all fuel filters.
  2. Cleaned injectors.
  3. Cleaned filter in vapor separator.
  4. New primer bulb.
  5. New low pressure fuel pumps.
  6. Cleaned O2 sensor.

It sneezes mainly when cold and when RPMs drop lower than recommended settings. I adjusted timing screw under correct water pressure conditions but it still sneezes.

My guesses as to what the problem is:

  1. An injector is sticking because after running for 20 minutes it stops sneezing at low rpms.
  2. It is still idling too low so it needs further idle adjustment?
  3. It has some sort of air restriction?

What say you?

www.purposeonecharters.com

2

if its “sneezing”, its running lean
figure out why it drops RPMS, and you will fix the problem and the symptom.
may need to do a “link and sync” on the butterflies"

I’m now at www.teamcharlestonmarine.com

3

Forgot to mention that it was Chris V who helped me get this far with it.

Thanks again Chris for your help.

www.purposeonecharters.com

4

Chris fixed the problem for me. My engine is now pretty quite for a two stroke. Thanks to Charleston Marine.

www.purposeonecharters.com

5

Hey Chris,

I’ve got a kind of similar issue while my 40 HP Merc is in gear, but not when out of gear. While in neutral and if warmed up, idles just fine and smoothly. But when I’m going idle speed in gear, it will eventually seem as if it runs out of gas and cuts off. If I advance the throttle just slightly, it stays running and is smooth, but is a slightly faster than I want to troll.
This 40HP 4 cylinder is the ‘Pan Fish’ model set up for slow-speed trolling, so I wonder what I can adjust? Carbs do not appear to have any outside adjustments as to mixture, so maybe slightly advance the ‘stop’ point for the throttle??

Many Thanks

6

I forgot to add, sometimes it does not want to crank right back up w/out the throttle advanced, even though it is warm…

7

H1N1

“Crawfish”
2008 Sea Fox 197 CC
2008 Suzuki 140

8

i have twin ox66 200 s and they were idleing low and burning lots of oil and found out the oil rod was out of adjustment i adjusted the rod they ran great the problem is there geting to much oil at a idle kind of loading up it would cause mine to idle at like 4 to 500 rpm when they should be idleing around 700 its a very good way to foul plugs

9
quote:
Originally posted by DropnHook29

i have twin ox66 200 s and they were idleing low and burning lots of oil and found out the oil rod was out of adjustment i adjusted the rod they ran great the problem is there geting to much oil at a idle kind of loading up it would cause mine to idle at like 4 to 500 rpm when they should be idleing around 700 its a very good way to foul plugs

was it keeping the #4 butterfly open

www.purposeonecharters.com