2002 OX66 sputters/surges between 1300/2200 rpms

[lswjth3@yahoo.com]

Thank you Rodbolt! The engine starts up at about 1100 or so rpm and aft about a minute and a half of so it will start to slow down rpm's and settle at about 700 or 800, I can then throttle it up to about 1100 and no surging occurs, if it I get it to about 1300 then the surging starts and it will stay surging to about 2200 or so...

I did buy a DVA meter adapter this week so I will test my stator voltages and they where at 60 volts on both windings which I thought may have been a little low?? I
Think that to get peak voltage you would multiply whatever you get by 1.3 as rms is
.7

I never did test the voltage out of the pulser coil, only the resistance from each white wire to Groundand all those were in spec, 300 ohms. Thxs again for all the help!! I will post back next weekend on my findings, I'm also going to replace one of my batteries as it's 4 years old although the problem still occurs on the other battery.

on my way out of town for work, have a great week!!!

[rodbolt17]

even if every thing is right on some hulls that motor danced between 1200 and 2000 give or take.
on a flusher or with no load it is worse.

[99yam40]

I did buy a DVA meter adapter this week so I will test my stator voltages and they where at 60 volts on both windings which I thought may have been a little low?? I
Think that to get peak voltage you would multiply whatever you get by 1.3 as rms is
.7

the DVA adapter and regular voltmeter will give you the peak voltage reading , no need to multiply anything.
did you have meter set to DC voltage?
instructions should have said to do that

sounds like that motor is not one to be using for fast *****ing

[rodbolt17]

if I was measuring peak without the adapter I would use the A/C setting and add 30-40% of what the meter shows.
most digital meters on A/C show RMS or WVDC.
that is about 70% of the wave form.
80 to 90 V peak simply isn't enough.

[lswjth3@yahoo.com]

99Yam, I did not have the dva adapter at the time, i just ordered one from Amazon and will take my stator coil and pulser coil voltages again when I get back from work, I do thank you for the help!

Rodbolt let's say that my stator voltages are low, the manual calls for 150v on both sides and when I checked with my meter, no DVA adapter and it does not read peak, I was getting 60 vdc output on each coil. Does this mean that I have a bad stator? I did check with my meter and it was 300 ohms on each side. I also had the engine at 3000 rpm when I took my readings.

I want to change one of my batteries as it's 4 years old and in the previous time that i have gone out I would get the "low voltage alarm" on my Lowrance HDS 8 unit.

The other battery is 1 year old, they are both Walmart group 29 batteries and I did move my battery switch to the newer battery and to "both" when the surging happens but it did not make a difference. I also kept an eye on the Yamaha gauge for the voltage reading and it was a steady 14volts when running, 12 vdc with the key to the "on" position, engine off.

Thank you again sir, hope you have a great day! I will report back when I get my readings and take the boat out for a spin..

[99yam40]

reading without the DVA on DC will not give anything to compare to specs.
Rod said how it can be done on AC.
DVA is the way to go.

If it was running I am sure it is within the specs

By the way spec is minimum, it will probably be higher when you measure properly

[lswjth3@yahoo.com]

Thank you, I will post my findings this weekend, again thxs for all the help! Have a great week!

[DennisG01]

It seems like you haven't had a chance to get it in the water, yet. Before you go chasing and testing all sorts of things, get it in the water and see if it still does it. I'm not saying the problem will positively go away, but it very well could. Maybe even just back it down the ramp and don't take it off the trailer.

[lswjth3@yahoo.com]

Thank you Dennis, I hope to take it our this weekend and I will report back, I appreciate this, thxs!

[lswjth3@yahoo.com]

All. I took the boat out today and it ran better than ever! No surging whatsoever at any rpm range, I ran it for 44 miles between idling out of the marina, cruising at 4400rpm (29mph) and WOT at 5500 Rpm (41 mph) and everything else in between and i could not be happier. It also gave my the best fuel economy ever, 1.99 MPG...

When I got back home I hooked it up to the ear muffs and yep, it would do the surging again, not sure why it does this on ear muffs but out in the Gulf today it ran like it was new. I want to thank everyone that took the time to read this and offer there help, again thank you!!

[Native 242]

What did you do