lower end buck

[miket]

1998 JOHNSON 115HP<br /><br />Sounds like a bump and the mid section and lower<br />end shakes or bumps intermitently. I can actually see the engine or midsection jump. Started at trolling speed, now it is doing it at high speed. Sometimes not happening.<br /><br />Any ideas

 

[OBJ]

Re: lower end buck

Hi miket.....<br /><br />First thing to do is check the gear lube for shavings or "sparklers". Also check the shift cable is adjusted properly and the lower unit is going into forward all the way. What you can try is to disconnect the shift cable and shift manually on the water and see if the engine still bumps.<br /><br />The symptoms indicates worn lobes on the clutch dog and possibly gear. "Sometimes not happening" is a little different.<br /><br />Do what I've suggested above and let us know what the results are. Have you owned the engine long? Also, when shifting into either gear, forward or reverse, do you snap it in gear or put it in slowly? The proper way is to snap it in.

 

[miket]

Re: lower end buck

Boat new to me this year, prior owner had Lower end unit in shop for new water pump and once over for $420, seems like a lot for a water pump.<br /><br />I put lower unit on realizing someone forced the shift rod between clutch dog and the gear case housing. Removed rod and had threads chased at machine shop and reinstalled setting height of rod according to manual. Had trouble engaging<br />but made cable adjustment until forward gear worked. <br /><br />Yes, I found shavings on both magnetic screws and first bit of oil was sparkling. Replaced oil and re-adjusted shift rod and will test today. Yes, I read Joe's post about shifting procedure. <br /><br />How long will I have until complete destruction of dog and forward gear? <br />Should I attempt to replace dog myself? I have worked on MG's for years, but realize I could be over my head when in gear case.<br /><br /><br />You pro's are great, I love to read about problem resolution rather than shop manual, as manual stinks when dealing with problems. Experience is the best teacher<br />Appreciate you response.<br />Mike<br /><br />If the fish are biting I'm not there.

 

[OBJ]

Re: lower end buck

Metal on the magnets isn't ever good to find. It means "something" isn't right. You may find small flakes on the magnets which is usually normal. But what you don't want to find is splinters or pieces.<br /><br />Disassembly of the gear case is not hard and can be done with your home mechanic tools. I would recommend a OEM service manual though before starting. Sounds like you have a generic manual like Clymers or Seyloc which sometimes are hard to follow.<br /><br />Don't know how long the gear case will last. But for sure, it won't get any better and the longer you let it go, the worse the damage can become meaning more bucks if the damage is really severe.<br /><br />If you do get into it, a couple things to look at are the the clutch and gear lobes which should have nice clean edges and not rounded off. No busted teeth on gears. The shift cradle should be flat on both sides and not wore in. This is often overlooked and needs replaced if worns. There is a multitude of bearings in there. Check them all.<br /><br />Let us know how you fare today on the water and we'll go from there. Could be you found the problem in the shift rod. Let's hope so!

 

[miket]

Re: lower end buck

OBJ - Took boat for test run tonight, no more buck in lower end, well maybe every now and again.<br />Nothing like it was on Saturday. The shift rod was incorrectly set by yours truly.<br /><br />Hopefully, this problems has been resoved.<br /><br />Thanks for you response.<br />Mike