Mercury 9.9 kicker problems

[duckbutter]

I've posted this problem a few times before and tried all the suggestions offered. I am now at my wit's end. I have an 05 kicker that I cannot get to stabilize in the lower rpm range. I don't have a tach, so the numbers I'm giving are just guesses. The motor idles just fine at I would guess somewhere in the 300 to 500 rpm range. When I increase the throttle (I also have a new Trollmaster installed) it jumps to about twice that amount. I have a 1900 pro v, and this jump keeps me from trolling at speeds between about 1.0mph and 1.9 or 2.0 rpm. I have had the carburetor torn apart twice, I have run everything suggested throught the gas tank, and now Mercury authorized a new carburetor. Nothing has helped. The motor worked perfectly for almost three years, and last fall, I started having this problem. I can gerryrig with drift socks, closing the windshield, raising the motor up, etc. to get the speed I want, but it just seems like this motor ought to perform at these levels without having to jump through hoops every time I change direction or if the wind changes, or I want to adjust my speed, etc. I would sure appreciate any ideas anybody has. I would like to get this solved this fall so when next season rolls around, I don't have to revisit this nagging problem. Thanks in advance for any advice----Mike Beuerle (duckbutter)

[teamlund]

I have an 08 pro kicker and I have the same issue. But not as extreme of a speed change... Check the trottle rigging/cable. Is there anything worn out, broken, bent, loose, or anything the way it shouldnt be that you can see..Just a thought...

[staylor]

..pull the cowl and find the throttle pick-up cam that opens the carb butterfly as you advance the throttle. Then start the motor and cycle it thru the rpm range where you have the problem while watching the linkage move. I think you'll find that the jump in rpm occurs just as the pick-up cam either starts to move the butterfly, or that you're on the cam and it starts to engage a ramp cut on the cam to open the butterfly quickly. Sometimes this jump is caused by a worn out of round or a flat spot of wear on the little plastic roller thats on the arm from the butterfly- or maybe the roller is stuck and won't freely roll- I've seen both on small Mercs. The roller is rarely looked at by mechanics and it only takes a slight imperfection to cause the linkage to make the butterfly suddenly jump open a little bit and give you a jump in rpm. Also, get a shop manual and see if the pick-up point for the cam on the roller has been set right.

If the roller is just sticking, clean grease off roller and the cam with a rag dipped in WD-40 and shoot some WD-40 on the roller where it's pressed onto the butterfly arm. After the grease/gunk is cleaned out lube the roller itself with a drop of Merc gearcase oil and lightly grease the cam surface with Lubriplate 105 white grease or some grease for your fishing reels. Then check to see if the roller now smoothly rolls up the cam with no jumping. If it still acts up, put on a new roller. If it acts up after that you may need to have the cam itself reshaped- but I've only had to do this once in 40 years on a Merc 25 hp with a really bad factory linkage design. I just had a similar problem on my 150 Opti after 5 years- an odd jump in rpm at slow trolling speeds. It turned out that the little roller was badly out of round from the factory, and had worn a small flat spot that was preventing it from rolling- it would just slide and not roll. My dealer gave me a new roller for free, and the install took about 5 minutes.....and the problem was gone.
Doug

[duckbutter]

Are you talking about where the linkage from the remote throttle control connects to the linkage? I have checked that, and it turns very smoothly. In addition, the Digital Trollmaster should eliminate any problem here I would think, as it advances the throttle very deliberately. My mechanical skills are limited. I talked with the tech people at Mercury Marine, and they just tell me to take it back to a certified Mercury mechanic. They say it could have something to do with the choke. I will recheck your suggestions again when I get back up north. Thanks for the advice.----Mike Beuerle

[staylor]

..and the Merc suggestion that it could be a bad choke adjustment or a sticking choke is related to the adjustment I talked about- and Merc may know of a specific issue on your particular engine thats not discussed openly- hence the hint about checking the chokes. You have to start right at the carb and start checking from the arm connected to the carb's butterfly. The chokes should not be touching anything if the choke is not engaged- but if they stick or the throttle roller is sticking this can give the problem you describe. A sticking linkage is probably beyond the capability of the digital idle control- it is programmed to assume nothing is sticking. You may have to try more than one mechanic to get this fixed properly. My Merc mechanic is pretty good with more than 20 years experience, but he was quite surprised that the little worn flat on my Opti's roller could cause an inconsistant idle with 200 rpm jumps in idle speed.
Doug

This sounds real similar to what was happening with mine. It ran a little rough at low speeds and would go from a high idle to 2.0 mph plus. I believe mind ended up being a partially clogged pilot jet in the carb. They ended up having to replace mine as they could not get it cleaned out.