New to me 94 25HP, couple questions,

RavenTai

Cadet
Joined
Aug 27, 2007
Messages
6
Picked up a 16' Alumacraft model K with a Johnson J25RERC S/N G 03572544, I bought it from an old man who just could not start it anymore, he says he bought it barely used in 95 and that it has low hours, that makes me the 3rd owner, with the exclusion of the mud dobbers it appears untouched and it still starts right up, the plugs are original, they have over spray from when the block was painted by the factory, they are worn down some, so how ever many hours it takes to wear in one set of plugs is how much time it has,

This afternoon I made a quickie stand from the plans on this forum, I simplified it and slapped it together in a hurry before thanksgiving dinner and it works great. cleaned and lubed everything, from what I can tell all I need are 2 new spark plugs, and gaskets to drain and fill the gear case, the tell-tale is strong so i don't think I need to do the water pump. what other preventative maintenance should I look into?

I have some questions My mechanical skills are strong but this is only my second boat, and the first lost a crank bearing the second time on the water,

1. air filter? My last Johnson, a 55hp from mid 70's had a plastic cover or baffle of sorts over the carb inlet, the carbs sprayed it with gas/oil and it tended to catch all the dust, this 94 25hp is just a bare carb, should there be something there? there was a good coating of oily/dusty/grime in the carb throat, I wiped it out but it leads to to wonder what the engine is eating?

2. also present on the 55 and missing on this one is a lifting ring, its doable by hand but my back would be happier getting it around with a lift, there is an open bolt hole in the block just aft of the flywheel, is that its intent? if not how is a good solid/safe way to get a sling on this thing?

3. spun prop vs aeration? on the test ride I had some oddities right as it got on plane where the motor would suddenly over rev, it was just me the fuel tank and engine on the boat and all three of us were in the back the bow was way too high, at the time I figured the prop was sucking air due to the odd angle, later I read about spun props, I took the prop off and the rubber looks ok, how would I go about determining whats going on?

4. tachometer, I have a hand head tachometer for my 2 stroke equip, but I would really like a semi-permanent tach, is there a easy way to run one on a tiller model? its a rope start and I do not have a battery on board, that may limit things.


5 I have a service manual on the way but in the mean time what is the torque for the spark plugs and the gear case drain/fill?
 

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oldcatamount

Lieutenant Commander
Joined
Apr 4, 2010
Messages
1,740
Re: New to me 94 25HP, couple questions,

It doesn't look like your motor has an "air cleaner". At best there would be a plastic cowling that would be empty and mainly used as a flame arrester, but, it doesn't show one on the parts diagrahm. As far as the lifting ring goes, I would say it's ok to use the empty bolt hole on the head. Just be sure your bolt goes through your ring and will thread into the head about 3/4 inch. The spun prop question you have is interesting. Could it be that you had the motor tilted to high and when the boat started to flatten out it put the prop to close to the surface? Did it do it more than once? You can do a test by making two corresponding marks (on the prop housing and on the prop hub), take a boat ride, when you're back at the ramp, take a look at the marks and see if they are still lined up. If they're not, you have a spun prop. On the tach, it all depends on which type tach you get. Most are going to require power from a battery but there are wireless tachs available. Can't help you with the torque question, but, a little common sense and you'll be fine.
 

narvlebenoit

Petty Officer 1st Class
Joined
Nov 22, 2009
Messages
224
Re: New to me 94 25HP, couple questions,

I had a 91 20 h.p. and the carb was just like that and I never had any problem.Sold it to a friend and hes still running it good luck with yours.
 
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