25hp Johnson - the good and the bad?

[itstippy]

Re: 25hp Johnson - the good and the bad?

I have run both 22ci 25HP's from the early 70's and 32ci 25's from the late 1970's. Big weight difference (as already mentioned). Big power difference, too. I don't think the 22ci model actually puts out a full 25HP. I think the later 32ci model puts out more than 25HP. Maybe it's the thru-hub exhaust. Maybe they fudged the ratings a bit to land on the magic "25HP" benchmark. I dunno. These motors were all in tiptop running condition. Both models are really nice pieces of machinery; I wouldn't hesitate to recommend either.
PS - you can get a 1970's 22ci to idle smoothly with a bit of tinkering. Read a recent string on this subject carefully.

 

[BF]

Re: 25hp Johnson - the good and the bad?

itstippy..... Yes, I've followed the other thread as well... other than the mod to collect or jettison the fuel from the re-circ line, I'm confident that my 25 is in a fine state of tune. Fast idle on up, it runs great. Maybe the re-circ is a big thing for the idle.... I'll probably be able to tell you in about the 2nd week of May next year.

dwagner27... yup, she's good company. and her tail keeps the flies away.... I've thought about glueing foam into the cowling too.... just never got around to it.

 

[pierretheron]

Re: 25hp Johnson - the good and the bad?

This is brilliant, you are all good men. I have the 15hp pushing a 3.5m (11.5ft) full inflatable that we use for crayfishing. Crayfish in Cape Town are like lobsters, very different to the US. One makes a meal, two make a feast. We have to take a fair amount of gear out with us, big steel rings with nets and usually 3 people, sometimes 4.

I really don't care how fast we go, so long as its on a plane. The boat weighs around 50kg (110lbs), with an inflatable keel and folding ply floor. With 2-3 up and gear, it get on a plain OK. I don't know if it going to make 4 up though. This is where my interest in a 25 comes in.

 

[BF]

Re: 25hp Johnson - the good and the bad?

Hi pierretheron...

Friends of mine had a zodiac inflatable of about that size in the 80's... they used a 30 hp evinrude tiller on it. With one light person in the boat it would do 35+ mph. But unless it was like glass, at that speed the vibrations from ripples would make your vision go wonky.... ahhhh, good times. We did lots of skiing behind that rig.

Their setup was they had the zodiac transom wheels. We'd inflate the boat, mount the wheels and then mount the motor (2 person job) all up, ~100 yards away from the water (at the campspot). Mounting the motor only meant moving it from the trunk of the car about 5 feet to the transom of the boat. Then wheel the whole outfit down to the lake (by hand). It was a decent shore/beach, but no boat launch. On nice ground, it was a one person job to wheel the boat. You'd just wheel it right into the water, and once floating, unscrew the nuts on the outside of the transom. The wheels would swivel up and float behind the boat, and you then remove them. It was a very slick system that took most of the pain away from putting a heavier motor on an inflatable. Of course, the ground had to be good enough to be able to wheel the boat into the water.

Anyway if the ground is not too rocky and there's a reasonable path to the shore it's something you might consider.

Another thing to factor in... I think it's particularly difficult to get the propp'ing spot on for inflatibles... If it's propped properly for a light load/empty boat, it'll be too much prop for a heavy load.... Also the other way, if you put a lower pitch prop on it to get on plane with a heavier load, it'd probably be in danger of over-rev'ing with an empty boat. (fixed by backing off the throttle a little with light loads). Load is a issue for all boats, but is greatly magnified when the boat weighs nearly nothing (IMHO).

You can feel the lack of mass when skiing behind an inflatable.... cutting hard greatly affects boat speed. We used to run slalom courses behind the zodiac.

My point being that maybe it'd be good for you to have a 2nd prop (a "load" prop) that you would use when you were going to have a particularly heavy load. Might help get you up on plane.

Good luck.

 

[dwagner47]

Re: 25hp Johnson - the good and the bad?

pierretheron:
I also have a 12 foot Achilles inflatable with inflatable keel and sectioned floor. The wood of the floor was replaced with white starboard material which is nice. I originally had a 9.8 hp Nissan which would make the boat plane with the 4 of us. My kids have grown and the 9.8 hp wasn't enough anymore so I bought the older Evinrude 18. Now it will plane easily with 5 (wife and kids weigh from 90-115 lbs), stay on plane at half throttle and probably hit 20-25 mph. With one person the thing is a hotrod. A friend had a 14 ft inflatable with a 35 hp and he said at full throttle it seemed that only the lower unit of the motor stayed in the water and he experienced the blurred vision like described above. I'm happy with 25 mph or so but I'd like to pull a tube if possible. I am now going to keep the boat on the trailer all summer so I only have to lug the motor around in Spring and Fall. Here is a photo of the boat with my fixed up motor.

 

[River - Runner]

Re: 25hp Johnson - the good and the bad?

This is my 1969 25 hp. 22 cube Johnson. For 1969 the 25 hp. was new and added to the lineup. Weighing in at 78 lbs, I think it must be the most hp. for the weight I know of. I bought it new, use it a lot and only the plugs, points and condenser have been replaced. If anyone is looking for and finds a similar motor I would always recommend buying it no matter how it's used. It is true that it's not in the league of a true trolling fishing motor but it does just fine. It does idle down quite smooth and I can never complain about that, but you can tell the motor was made to go fast, because it is factory souped up. As for gas usage it's meaningless to me, but it does use the same as some larger newer motors. I can't say anything else bad about it.

I'll add that it starts so easy I sometimes will rope start it in gear when I want to.

 

[dwagner47]

Re: 25hp Johnson - the good and the bad?

Your motor looks to be in fantastic condition. I'd love to find a motor like yours used (but the evinrude matches my blue inflatable better). The weight for my 1973 Evinrude 18 is 86 lbs. Looks like the Johnson shaves a few pounds by making the bottom part of the cowling even shorter. Great pictures!

 

[itstippy]

Re: 25hp Johnson - the good and the bad?

See eBay item 140061217235. Just type the number in the "search" box and click "search".

No, it's not mine. Looks nice, though, and this guy in Slinger has been selling motors for a while on eBay.

EDIT: I just noticed that the emblem on the front of the cowl seems to say "Electric". The model number is a rope start. What's up with that?

 

[whywhyzed]

Re: 25hp Johnson - the good and the bad?

I have a similar setup as DWagner. Here's my Avon 11'2" with it's 1975 20HP Evinrude. I sure wouldn't want a motor any heavier on my transom or for lifting and I'm a big guy.
I would like to find a 25HP actually - I like speed. I bought a SS prop for my 20, but the motor needs the extra 5 ponies for the SS to show any gain over the alum.
http://i5.photobucket.com/albums/y184/hystat/cats06032.jpg?t=1165776559

It will plane with 4 people with the 20, but again, one of those 22 cube 25HP motors would be the best thing.

My 20 has a chronic lean sneeze at idle. I have figured out how to use the mixture knob when coming off plane to compensate - I'm off to find that other thread you are all discussing - thanks- I am interested in this mod.

 

[whywhyzed]

Re: 25hp Johnson - the good and the bad?

PS - you can get a 1970's 22ci to idle smoothly with a bit of tinkering. Read a recent string on this subject carefully.

hmmm... can someone help me find that thread please... i cant seem to find it....
tks.

 

[itstippy]

Re: 25hp Johnson - the good and the bad?

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1210752

 

[dwagner47]

Re: 25hp Johnson - the good and the bad?

kikik:

When tinkering with my Evinrude 18 I was plaqued with the lean sneeze also. I adjusted the mixture rich enough so it would go away at idle but when throttling down off plane quickly the motor would sneeze. I then adjusted the carb synch so the carb throttle plate would open sooner and the lean sneeze problems went away. I found that I had initially set up the carb synch so the throttle plate was opening when the little roller was between the 2 marks on the flywheel. Wrong 2 marks! After reading the manual for the 10th time I see that the 2 marks I am supposed to use are on the cam itself not the flywheel. My hard starting issues when the motor was cold also went away after this adjustment. A 6 inch pull will start it when it is warm.

 

[dwagner47]

Re: 25hp Johnson - the good and the bad?

itstippy:

I saw that motor on eBay before. Looks like it has a Johnson powerhead (green) and looks like it has been repainted with new decals. I can't tell but it looks like a 1970 or 1971 due to the rounded versus square lower motor mount housing and coils are under the flywheel. It even looks like the grip on the tiller was spray painted white.

I bought my Evinrude 18 on eBay a few months ago. It wasn't in as good cosmetic shape but it was all original. A little cleanup and paint for the cowling and motor leg made it look pretty good.

 

[dwagner47]

Re: 25hp Johnson - the good and the bad?

Actually I think the eBay motor is a Johnson repainted with an Evinrude cowl. You can see the overspray on the inside of the lower cowl.

 

[River - Runner]

Re: 25hp Johnson - the good and the bad?

Your motor looks to be in fantastic condition. I'd love to find a motor like yours used (but the evinrude matches my blue inflatable better). The weight for my 1973 Evinrude 18 is 86 lbs. Looks like the Johnson shaves a few pounds by making the bottom part of the cowling even shorter. Great pictures!

dwagner..... Thanks for the motor complement and it's never been touched up. I'm just careful with it. It even has the original shear pin, it just bends and doesn't shear. The original prop is white, which I have. Pictured is a black 2nd prop.

My 1969 brochure literature says the 25 hp. weighs less than 80 lbs. I weighed mine and it is 78 lbs.

The Johnson and Evinrude motors of the same year were always the same motor other than the color, graphics and appliques. As years progressed the motors got heavier with beefier components and add-ons. To make them better? Then later with bigger engine blocks and to be prop rated hp. Compared to today's motors these old motors are so light, with weights never to be seen again. They say new is better, but they sure are heavy, to bad for that.

I have the newer motors, but this is my favorite one. It's a so simple motor and it will probably outlast me.

 

[whywhyzed]

Re: 25hp Johnson - the good and the bad?

kikik:

When tinkering with my Evinrude 18 I was plaqued with the lean sneeze also. I adjusted the mixture rich enough so it would go away at idle but when throttling down off plane quickly the motor would sneeze. I then adjusted the carb synch so the carb throttle plate would open sooner and the lean sneeze problems went away. I found that I had initially set up the carb synch so the throttle plate was opening when the little roller was between the 2 marks on the flywheel. Wrong 2 marks! After reading the manual for the 10th time I see that the 2 marks I am supposed to use are on the cam itself not the flywheel. My hard starting issues when the motor was cold also went away after this adjustment. A 6 inch pull will start it when it is warm.

Thanks - I just printed this - sounds like exactly what i need to check!

& Thanks for the link itstippy

 

[River - Runner]

Re: 25hp Johnson - the good and the bad?

This might be of interest to someone.

I bought one of the first 25 hp. 22 cube motors. When I took it in to the dealer for a checkup after break in, he had his mechanic drill either one or two 7/32 holes up at an angle in the upper water exhaust opening, using a fixture and electric hand drill. They said it was to be done to breathe better. It ran fine before this was done but if I wouldn't have took it in, it would never have been done.

You should have two angled holes there, one above the other. Over the years, sometimes I will see motors like mine and I will check if they have those two holes. They all did.

Also, after I use this motor I slowly pull the rope a couple of times as to not start it and tilt it up. The motor will hold a little water, doing this drains it out.

 

[dwagner47]

Re: 25hp Johnson - the good and the bad?

My 1973 motor has these 2 holes. My local OMC dealer talked about this procedure as well. I've noticed that while my motor is running there is a trickle of water coming out of a small hole in the fore side of the leg at about waterline level just above the motor mounts. Has anyone else noticed that?

 

[River - Runner]

Re: 25hp Johnson - the good and the bad?

My 1969 motor has three small holes, all down low on the shifter side of the motor. One is just above the anti-ventilation plate to the front. The other two are below the plate midway to the gear housing, one to the front and one to the rear.

That I know of they are drain holes, because I only notice water draining from them. I check to see that they are open when I think of checking, because I did have one or two get clogged and I just use a toothpick to clean them out.

 

[jspringator]

Re: 25hp Johnson - the good and the bad?

Great thread, but I am trying to find the thread referenced herein regarding how to make these 22 CI's idle smoother. Here is the thread on the old system:

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1210752

Can anyone convert it? Thanks!