what did i do?/76' 25hp screwed up

[tjl76evinrude]

SO i decided i could fix my little issue. its a 1976 25hp evinrude. had been running pretty good. perfect except for a miss on throttle up. it would lag a little like missing on 1 cyl. if i gassed it harder though it would come out of it and run great. seemed like the issue had been getting worse but it still wasnt too bad. but i figured i could make it better.. thats where it went wrong.

i went to re-gap my points(.20). didnt run so great afterwards, i tried adjusting carb also(i know i shouldnt have..). re-adjusted points again, it wasnt happy.. this time i didnt torque the flywheel down. tried starting again, sheared the woodruff key so that shut me down for a while.

also while i was in there before, the points/condensers had oil on them so i shot them with carb cleaner to dry off. think that screwed them up.

SO today i put a new woodruff in, flywheel on, it fired right up fairly happy ran for a lil then i shut it off to put more water in the bucket(lower unit was it in). restarted, ran a few seconds then stopped. after that i couldnt get it to fire again. now im tired of it and want a new boat...

 

[BSDenning]

Re: what did i do?/76' 25hp screwed up

It's always a good idea to try one thing at a time. For example, set the points, test the motor, adjust carb, test the motor. Since you did both, it's hard to tell which is your problem. It could be either one. I'd say recheck your gap on the points. Play with them a little bit and if you can't get it started then try the carb.

 

[ovnic1234]

Re: what did i do?/76' 25hp screwed up

Fuel/oil mix blowing by the top crankcase seal getting on the points and condessors? From what I gather from here and from hounding an mechanic with questions. A loss of crankcase pressure from a leaky seal can cause a cylinder to get a leaner mix. One plug will be much wetter than the other.

Just a thought, It may not be the problem, but it sounds like it's having the same trouble as a motor I am fooling with. I ordered seals today.

 

[tjl76evinrude]

Re: what did i do?/76' 25hp screwed up

i did notice on the previous round of tinkering that there was air escaping at the crank case seal. not sure if its worth replacing though... this motor unfortunately lived its like on the saltwater so the hardware is pretty rusted up.

 

[Lucraft]

Re: what did i do?/76' 25hp screwed up

tjl76, I'm working on a 1974 Johnson 25 that sat in my neighbor's yard for 4 years. It was also a saltwater motor and has seen better days, but I'm determined to get this thing running right.

When I first got it I managed to get it started only to find that it didn't want to stay running. Cleaning the carb helped that. It also had (has) weak spark on one cylinder that I haven't quite figured out yet. I'm waiting on some parts to come in before I mess with it more, but it's a pretty simple motor overall.

Anyway, I'm up in St. Augustine and if you want to make the drive, you're welcome to bring the 25 up here and we can take a look at it. Though it sounds like you've already got it figured it out. Gaskets sets are pretty cheap; they're just a lot of work to replace. If you decide to get rid of the 25, please let me know as my motor needs random odds and ends and I'd be interested. Thanks!

 

[ovnic1234]

Re: what did i do?/76' 25hp screwed up

I paid around 10 bucks for the seal. Not that bad.

I have had my first run-in with a motor that was used in saltwater a little while ago. I bought it for parts, it had overheated and seized. The fresh impeller that was in it didn't do a lot of good. The water jackets were full of crap.

 

[ovnic1234]

Re: what did i do?/76' 25hp screwed up

Oh yeah,

It sounds like the seal. The progression from good to worse. Oil on points/condensers. Air escaping. I believe trash in the reed valves can produce the same effect.

Okay, that's it. Best of luck.

 

[tjl76evinrude]

Re: what did i do?/76' 25hp screwed up

thanks for the info. how far of a teardown is needed to replace the seals? the powerhead was covered in oil for while from a leaking top crank seal so the bolts look to be in decent shape. im still just scared to get into it, maybe start having bolts break and ruining it.

this boat and motor belonged to my grandfather, its the rig that i grew up fishing on and now i own it. its not worth much $$ but sentimentally the thing is irreplaceable so i dont want to have it crap out.

i do need to get into the front of the motor anyways since my front motor mount rotted away and fell out a long time ago. its not available so i need to get in there and make something work for it.

 

[Lucraft]

Re: what did i do?/76' 25hp screwed up

thanks for the info. how far of a teardown is needed to replace the seals? the powerhead was covered in oil for while from a leaking top crank seal so the bolts look to be in decent shape. im still just scared to get into it, maybe start having bolts break and ruining it.

This should give you an idea of the teardown:

http://www.crowleymarine.com/johnson-evinrude/parts/30073.cfm

i do need to get into the front of the motor anyways since my front motor mount rotted away and fell out a long time ago. its not available so i need to get in there and make something work for it.

I'll ask my friend if he has a good one laying around.

 

[ovnic1234]

Re: what did i do?/76' 25hp screwed up

I haven't had much luck searching this forum on how to remove the seal. I'm sure it's here somewhere just haven't found it yet. From what I can tell the seal is made like the prop shaft or crankshaft seal in the lower unit, but bigger. Stamped ring with rubber seal.

I was planning on drilling a two small holes one at 3 o'clock the other opposite at 9 o'clock. (3/9 just opposite of each other, you get it) Using a bit that is maybe a 1/16" dia. at the most, with a magnet right by it to pick up the waste. Then lightly screw drywall screws into both holes. With a block of wood to pivot on and a mini flat bar (pry bar) work from one screw to the other evenly pulling the seal out.

I hope this is helpful. Maybe someone has a better approach. Maybe some more searching of this forum will yield a tried and true solution

 

[318schippa]

Re: what did i do?/76' 25hp screwed up

I sheered off my key also from not torqing the flywheel down. I have the same motor...could you tell me the torque I need? Thanks

 

[Brokeback Johnson]

Re: what did i do?/76' 25hp screwed up

New points and condensers are cheap and could very well solve your problem.

 

[wilde1j]

Re: what did i do?/76' 25hp screwed up

Per F_R:

Flywheel keys shear because somebody has installed the flywheel incorrectly. Every time it happens, it damages the flywheel and shaft. Do it enough times and you have junk.

1. The flywheel and shaft tapers MUST be clean and dry. And not all beat up.
2. You MUST use a torque wrench to tighten the nut to ft/lbs specified in the OEM shop manual for your motor.

Failure to follow the rules causes sheared keys and damaged parts.