Hey mmt. As you may know I have a 31hp gator tail stage 1 w/ stage 3 heads. While on a hunting trip during the week my motor ran great but on the way back it wouldent turn up over 1800 rpm in the water. Out it would turn 4500+. Well I made it home and cleaned the carb (which was already very clean) and dumped all my old gas out and refilled with non ethanol 93. Well still same problem. The motor spits and spudders and ocasionally throws flame out the exhaust while at low rpm. Well after I get past 1800 or so the motor has full power and runs great. Only out the water though . IF I try to quickly open the throttle it falls on it's ass but if I open it slowly it'll spool up. I do notice my rev limiter is making a slight electrical static sound but dident pay much attention before so this might be normal. Odd thing is was on my way back from hunting when it started acting up it would all of a sudden hammer down with full power and take off, run for maby 1 or 2 min like that then bog back down. I dont want to bring it to a shop right now because ill miss the last 2 days of ducks. Heres a list of what I did to diagnose with no luck. Any help?

1. Empty old gas and fill with fresh.
2. Clean carb.
3. Pull the plugs sepretly to see if im running on both cyl.
4. compression test.
5. change spark plugs and check for fowling.
6.change primer ball to make sure no air leaks.

disconnct rev box

X2 on da rev box
if dat is not the problem then remove your valve cover and with your kill switch pulled turn you motor over a few times and see if all of your valves are moving to der full range. You may have a lobe on you cam wearing down.

Well I swear.....

I have the about the same problem.

I noticed headed back to the ramp I was down to about 3,300 on my Pro-Drive about a week ago. Went on a trip and have not run my boat. Went out today. 2,700 max in gear. Got down to 1,700 and then would not run or start.

Changed plugs.
I have fuel pump and it is pushing gas.
Changed fuel line 2 weeks ago. 2 new filters.

Now it will sounds rough and will not idle or run smooth.

????????????????

Sounds like the timing or something is wrong. Pulled each plug wire runs a bit better on the left and will not run on just the right cyl..


I do not know what to check next?

sounds kinda like a bad coil problem i wuz havin on an outboard

Ok, long shot, but occasionally my choke lever will migrate with engine vibration and my rpms will drop gradually. I just reach back and pull it forward and rpms back up to normal. It took a while to figure out what was wrong. I thought my motor was having serious issues for a day or two until I figured this out.

Darrel, did you get fixed up?

hey guys, I just got back from a week long hunting trip so sorry for not keeping yall posted. I did fix her. Turned out to be my power wire on my rev limiter got kicked out of the but connecter but stayed in there, so I guess it was making a connection every now and then but a really shitty one that was the electrical sound I was hearing. Also, I noticed I had a split in my gas hose at my primer ball where my hose clamp got pushed back and it was sucking air bad. It wouldent hold a good prime. It would have enough primmed gas to run and spool up slowld but when I hammered down on her it simply wouldent deliver the gas needed so it would bog. Im just glad it was really simple issues and not a cam failing. Thanks for all who helped!