30 horse johnson acting funny

[mrbrink]

took my boat out for a shakedown run with the new motor, a 56 30hp johnson. after figuring out I hooked the air and fuel lines up backwards ( had a leak, gotta love old hoses) it started right up. After running for about 20 minutes and adjusting the mix to get it running decently, we headed out to the lake. 3 different times it felt like i hit something at 3/4-WOT, just a quick jolt from the motor but I know I was in 20 feet of water in a muddy bottom lake. Also at idle and in neutral, it would do the same random cough/jolt, sometimes even die. In gear, it'll idle all day long and not hickup once. Anyone have any idea on whats going on here? I put new plugs in it before we went out and also had fresh gas in the tank.
Thank you for the help.

Also, on a 14' fiberglass boat, how do you think this motor should perform?
The boat was empty, 2 people (160 lbs and 200 lbs) and it was a dog to get on plane and seemed like it should have some more throttle to it. Linkages are adjusted correctly. I forgot my gps but I'd say I never broke 20 mph

 

[F_R]

Re: 30 horse johnson acting funny

took my boat out for a shakedown run with the new motor, a 56 30hp johnson. after figuring out I hooked the air and fuel lines up backwards ( had a leak, gotta love old hoses) it started right up. After running for about 20 minutes and adjusting the mix to get it running decently, we headed out to the lake. 3 different times it felt like i hit something at 3/4-WOT, just a quick jolt from the motor but I know I was in 20 feet of water in a muddy bottom lake. Also at idle and in neutral, it would do the same random cough/jolt, sometimes even die. In gear, it'll idle all day long and not hickup once. Anyone have any idea on whats going on here? I put new plugs in it before we went out and also had fresh gas in the tank.
Thank you for the help.

Also, on a 14' fiberglass boat, how do you think this motor should perform?
The boat was empty, 2 people (160 lbs and 200 lbs) and it was a dog to get on plane and seemed like it should have some more throttle to it. Linkages are adjusted correctly. I forgot my gps but I'd say I never broke 20 mph

Your "hitting something" in 20 feet of water is a classic symptom that outboard mechanics hear almost daily. You have a worn out clutch dog, and possibly forward gear. Here in FL, the story goes "feels like I hit a gator".

What is happening is it is coming out of gear, rotating one half turn, and slamming back into gear. Till the next time. The more power you apply, the oftener it happens. Every time it happens, it destroys the dog and gear a bit more.

 

[mrbrink]

Re: 30 horse johnson acting funny

Okay thanks for the reply. I'll split the lower unit and see about getting some new parts.
As for the idle in neutral issue, I was thinking maybe a lean pop?

 

[14ftgrumman]

Re: 30 horse johnson acting funny

was that "Ha Ha" funny or "strange" funny?
Sounds like clutch dog.
Every once and a while they turn up on eBay. Run it too much like that and the gears will be right behind. You could buy some time and turn the dog around? if your LU is like the 18 thru 25's of the late 60's up to the early 70's.

 

[cougar1985]

Re: 30 horse johnson acting funny

clutch dog is avaible from brp dealers, part number is 0375783.i bought mine a year ago for a 56 30 johnny i was fooling around with.

 

[mrbrink]

Re: 30 horse johnson acting funny

The local boat dealer had one in stock so I picked it up. They wanted 60 bucks for that thing!
oh well, at least I'll know the boat will be up to par before my fishing trip this weekend

 

[J.R.]

Re: 30 horse johnson acting funny

I have a 28 HP 1963 Johnson, Motor only 500 and boat and trailer included for 900. it runs good, Boat does not have controls hooked to motor, shout if interested.

 

[steelespike]

Re: 30 horse johnson acting funny

The original 30 hp was listed for 30 mph on a light reasonably fast boat.
Setup correctly with the right prop I would think 25 to 28 could be possible.
Should get on plane fairly easy.Be sure the carb opens all the way and the stator rotates correctly.I assume you adjusted the high speed mix at speed.
Do you know the prop size?

 

[1946Zephyr]

Re: 30 horse johnson acting funny

WAIT!!!

STOP!!!

don't tear it down yet until you check the linkage adjustment. Holy gads people. How do you know you won't have this guy doing an unneccessary tear down, until this is checked? These things as well as the 18's, 35's and 40's were built with adjustable shift linkage for a reason. So.................you can re-adjust things when things start going chunk chunk chunk......

I have seen countless teardowns, only to find that the lower unit was really not the issue. If your lower unit has clean oil in it and no water intrusion, then a "bad Clutch Dawg" is less likely the reason. However, if you pull the drain plug and a bunch of sewage looking pukes out, then there is a good place to look.

One way to find out if your linkkage is out of adjustment, is to take ahold of the prop with your left hand and take ahold of the shifter with your right hand. Turn your prop while going from neutral to forward. The do it again going from neutral to reverse. Do they engage at the same point from the neutral position? If they do, how far does the shifter travel, before they engage? You could possibly just have a sloppy shift rod too.

There are a few "free checks" before you run out and buy a "clutch dawg" which may or may not fix thhe problem.

 

[mrbrink]

Re: 30 horse johnson acting funny

Too late, already got the new clutch dog in. the old one was getting pretty rounded off, the forward and reverse gears still looked pretty good. Everything seems to hook up fine now, going to the lake tomorrow to give it a test.
On the first test run, the motor wouldnt plane the boat out and was very doggy. High speed made no difference, but making the low speed richer got it to open up more. I still need to play with the settings some more. BTW I was adjusting the high speed at WOT. I don't know what size prop is on there but I'll check tomorrow when there is some day light.
The gear oil was white and thick, I know the guy before me put that lubriplate 105 in there and its white and thick so im pretty sure i don't have water in the lower unit, but I replaced the seals while I had it apart anyway.
Where would I find these linkage adjustments? If I have issues tomorrow I'll play around with them too. Yesterday it would go into forward just fine but reverse sucked. I had to adjust my control box linkages and still hold the lever all the way down for it to kinda enguage

 

[cougar1985]

Re: 30 horse johnson acting funny

holy gads zephyr all i did was tell him it was still available!rounded sounds pooched to me!bad doggie, bad bad,lol.

 

[1946Zephyr]

Re: 30 horse johnson acting funny



Those adjustments are right up at the shift handle. You'll see a longated hole with a nut and screw in it and of course, the clamping nut and screw on the shifter.

 

[mrbrink]

Re: 30 horse johnson acting funny

Here are todays results:
By myself with a full tank of gas, on same 14' fiberglass boat I got 22 mph out of it according to the fish finder. That was after some more adjustments to the fuel air mix. No more clunking under power, stays in reverse, I'm a happy camper I still think I should get a little more power out of it, but I may be over propped. I forgot to see what it was but I'll do it tomorrow when I change the lower unit oil and post it. I lost one of the screws on my lower unit today so I'm going to put fresh oil in incase some water worked its way in there