More problems with '75 Evinrude

combat

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Got back out on the lake once more today after finding out we were missing parts for the cooling system on the motor...replaced those and today the boat just didn't seem to want to run full power...we're really not sure why...we tried playing with the fuel delivery cause often times it starts out running a little lean so we turn the knob to rich until she kicks into high...but today it just putted along about the speed of a 9-10 hp motor would....

My cousin ran the motor for most of the trip and he said that at one point while the motor was running and the cover was off that he screwed the needle on the front of the carb all the way in and it was still running...so I'm not really sure if something may have came loose and fell out or what but it definitely did not have the power it had last weekend when we took it out....we did have an extra body in the boat, but I don't really think it should have made that big of a difference...We also had to start it in forward when normally we have no trouble at all starting it in neutral...usually takes 2-3 pulls and it starts...gave us a hell of a time today

Any ideas?

I guess it would also be good to mention that when the motor is actually running in the FAST position and going half speed I BARELY...and I mean...maybe 1/4" turn it toward slow when I need to slow down and it nearly dies....I can't even get it half way to the SLOW position on the handle and it dies
 

jimdd810

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Re: More problems with '75 Evinrude

Sounds as if you need to rebuild the carb. Also do a compression check.
 

combat

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Re: More problems with '75 Evinrude

We did a compression check last week when we overheated and found out we blew some gaskets...replaced but had already returned the rented tool. Carb was cleaned when I got it but I suspected also that it may need a rebuild. Gonna do a cleaning with seafoam and see if that might help it any...if anyone else has any opinions drop a line here and I will see them later.
 

HighTrim

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Re: More problems with '75 Evinrude

First ensure that you have spark on all cylinders. What size motor are we talking about here anyways?

If you have spark and compression, there is a fault with your fuel delivery. I would reccomend you get yourself a factory OEM Service manual. Your carbs may likely need cleaning/rebuild then set up the linkage afterwards. There is a thread by Joe Reeves in the stickies regarding setting the needles.

Running sea foam through the fuel is NOT going to clean your carbs in any way. The only way to do this is to take them apart and clean thoroughally and properly.
 

combat

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Re: More problems with '75 Evinrude

Any ideas as to what might cause the motor to start in forward great instead of neutral like it should?
 

jtexas

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Re: More problems with '75 Evinrude

what the heck motor is this, anyway? Evinrude made about 500 different motors in 1975.
 

combat

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Re: More problems with '75 Evinrude

Sorry keep forgetting...made that last post on my phone.

It's a 25hp model # 25553B

Did the seafoam earlier and now it will start in neutral but its hard to get it started in neutral...10-15 pulls at least is what it takes. This motor has been giving me nothing but trouble since I got it...and now today my cousin noticed it spit out some oil when it backfired.
 

combat

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Re: More problems with '75 Evinrude

Ok...got the compression checked once again today. 90 lb on top cylinder, 70 on lower. Should be plenty to start without taking 10-15 rope pulls.

One other thing I noticed. We took the lower unit out to replace a water tube earlier last week, put new oil in once again. The oil is now leaking from the sections of the lower unit (it's a long shaft)...we are going to just silicone that up so it doesn't leak but there is also a hole near the bottom where it looks like oil is seeping from...anyone ever heard of this?

The hole I'm talking about you can see in the picture below...look for part #5 and it's near the back side of the lower unit.

convert
 

Daviet

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Re: More problems with '75 Evinrude

I think the hole you are getting ready to plug up is a drain for the exhaust housing, I wouldn't plug it.
 

combat

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Re: More problems with '75 Evinrude

Oh I wasn't going to plug it...I've seen water come from it so I know it is there for a reason but I wasn't sure why oil was coming from it. I've been reading around and it might be that gear oil is getting past the water pump seal...I'll have to look at it tonight and see what is going on...getting tired of buying oil for this thing cause i have to keep dropping the lower unit and draining it...I think this will be my 3rd bottle.
 

Howard Sterndrive

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Re: More problems with '75 Evinrude

Ok...got the compression checked once again today. 90 lb on top cylinder, 70 on lower. Should be plenty to start without taking 10-15 rope pulls.
I dunno
My 1975 25HP Johnson has 125/125
 

jtexas

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Re: More problems with '75 Evinrude

Ok...got the compression checked once again today. 90 lb on top cylinder, 70 on lower. Should be plenty to start without taking 10-15 rope pulls. ...

nope, too much difference. 90-90 would be ok, or even 90-85. That's your problem right there, that motor's not ever gonna run satisfactorily without compression.

no need to put silicone on the motor. water running out the lower unit hurts nothing, its submerged anyway.
 

combat

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Re: More problems with '75 Evinrude

nope, too much difference. 90-90 would be ok, or even 90-85. That's your problem right there, that motor's not ever gonna run satisfactorily without compression.

no need to put silicone on the motor. water running out the lower unit hurts nothing, its submerged anyway.

It's a long shaft and it was leaking gear oil from where the sections come together, turns out it was MORE PROBLEMS.....took everything apart today to fix the gear oil problem and found out that the bearing at the bottom of the gear shaft was pretty much EFFED UP...so now I have to order a new one...and somehow figure out how to get the old one out...

Has anyone ever ordered from L&M Marine?
 

HighTrim

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Re: More problems with '75 Evinrude

Im just going to give you my personal opinion. Dont spend any money or order any parts until you determine the cause of the low compression and determine how much you want to put into this motor.
 

combat

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Re: More problems with '75 Evinrude

Well I've already ordered the bearing and seal. Wasn't much...$27.

What are the chances that I can pull the head off without ruining the gasket if it's not already messed up? Only reason I ask is that I know sometimes they will break when they are older like this one probably is, although I'm not 100% against pulling the head off...I'd just much rather not have to buy a new head gasket if there is nothing wrong with that one.
 

Sixmark

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Jul 11, 2010
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Re: More problems with '75 Evinrude

Head gaskets are not generally a reuseable item so don't reuse it
 

jtexas

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Re: More problems with '75 Evinrude

I would not even consider reusing it.
 
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