Problem with Johnson 150 "Jerking"

[KJW83]

well i've had the boat in the shop for over a month now. they replaced the water pump and cleaned the carbs, which went well. but there having trouble figuring out why the motor has a jerk to it when you come up on plane. it doesn't matter how your trimmed, or how fast your going it still has a little jerk to it every minute or so. they replaced the gearset in the lower unit, along with new fluid, but still cannot pin point whats going on with it. the mechanic just called me and said he's had it out on the water about 10 times the last two days adjusting on it and seems to think its slipping in and out of gear. but why would it do that if he just put new gears in it? any info on this problem would be great!! sorry i forgot to mention, model no. is J150ELANC

[ChampioNman]

rounded ears on the clutch dog perhaps? What is the model year?

[KJW83]

its a 1992

[ChampioNman]

Got to say clutch dog ears rounded . Or did you whack something out on KY lake?

[316jughead]

I would think if they replaced gears, the new clutch dog comes with the reverse because of the more dogs on the gear. At least mine did. It probably is the power pack, it will cut in and out so fast it seems like it is jumping out of gear. My 1991 did the same thing, after inspecting the clutch dog and gears, which looked like new, it still felt like it was jumping out of gear. I replaced all the gears and dog and it still did it. It finally started doing it just running down the lake. I had a power pack with me so I put it on and it hasn't "jumped out of gear" in six years. Might not be your problem, but it sure was mine.

"So, you want to be an Evinrude tech, do Ya"


Modified by 316jughead at 9:11 PM 8/4/2010

[KJW83]

why, and how does a power pack go bad? what does it cost to replace it generally? i'll mention it to them next time i talk with them.

[316jughead]

On the lake 10 times in two days adjusting what? One shift rod height, set when replacing gears, a little bit of leway in adjusting the shift cable. If your motor has the shift interupter switch maybe some adustment there but that's about it. All of this is done in the shop, if it is all set correctly no adjustments will solve a jump out of gear. How did the gears look that he replaced? Correct shift rod height? If your tech is satisfied that the lower unit is OK, my bet is on the pack and eye. We had a recall in 92 on these packs, but surely yours has been replaced. I had a problem after a hard run, the motor would just die at idle, idle about one minute and die, it would start right back up. Checked everything I could think of, finally replaced the pack and eye, no more problems. This was why I replaced the pack and eye when it felt like it was jumping out of gear.

[SEAHORSE]

One thing to check is the horizontal shift shaft that goes under the carbs. If the weld on the end of it cracks, then there will be play in the linkage that could keep the gearcase from staying in gear or from going completely into gear.

Also check the lever where the plastic link and shift cable attaches. It is stamped metal and the inner part where the link attaches can bend throwing off the linkage geometry.