1978 Evinrude 70HP- Trouble starting/idling/bogging under load

[evinrude2323]

"wet plugs" "starts and dies" "black fluid running from lower"

Spark jump test....buy a cheap one, $15 at any auto parts store or get a nice one online.

Could be one of many electrical issues. Rule out each thing and move on.

Once running, take it out on the water and magically watch the sludge go away.

So you are leaning toward it being an electrical isssue?

 

[evinrude2323]

Try this. Nice blue 3/8 crack.

I have this arriving tomorrow. In the meantime what should I try? Do they run different when they have muffs vs being in the water?

 

[evinrude2323]

I’ll pull the cylinder head off and take a peak at head gasket

 

[racerone]

Look at condition of cylinder walls.----Post pictures.

 

[evinrude2323]

Look at condition of cylinder walls.----Post pictures.

I really won’t have to mess with timing? I’ve done timing belts in the past but would rather not on this one.

 

[racerone]

I clearly indicated to you that there are no timing issues !!----There is no belt.----There are no valves.

 

[saltchuckmatt]

Muffs are for flushing mainly or doing small adjustments at or near idle...

I would not tear down the engine until you check for good spark.

 

[evinrude2323]

Muffs are for flushing mainly or doing small adjustments at or near idle...

I would not tear down the engine until you check for good spark.

Copy that I’ll wait for spark

 

[evinrude2323]

I clearly indicated to you that there are no timing issues !!----There is no belt.----There are no valves.

My bad just double checking! I’ll get some photos up very soon for everyone.

 

[tphoyt]

It wouldn’t hurt to take a peek at the fuel pump as well. Kits are cheap and if it’s the original it’s probably due to be refreshed anyway.
A leaking diaphragm will add extra fuel directly to the cylinder adding more fuel than needed.
Could result in one plug being more wet than others and to the black crud your seeing from the exhaust. If you can get it into a trash can instead of the muffs. It makes a difference.
Jmo

 

[evinrude2323]

It wouldn’t hurt to take a peek at the fuel pump as well. Kits are cheap and if it’s the original it’s probably due to be refreshed anyway.
A leaking diaphragm will add extra fuel directly to the cylinder adding more fuel than needed.
Could result in one plug being more wet than others and to the black crud your seeing from the exhaust. If you can get it into a trash can instead of the muffs. It makes a difference.
Jmo

I will get it into a trash can 100%. I also think that this engine just needs some love and new parts. I found a video that I will link in this message that I am going to use as a guide. I likely wont rework the heads, but after seeing this video I would love to get the head off and check the pistons and cylinder walls. And I agree the fuel pump is definitely getting an inspection and new diaphragm.

Thanks for all the help everyone! I'll keep posting and get some pictures of it up.

 

[tphoyt]

Pulling the head is well worth the effort.
If for nothing else you have inspection notes for future reference.
Resurfacing the head is easy and would be worth the time spent.

 

[evinrude2323]

Pulling the head is well worth the effort.
If for nothing else you have inspection notes for future reference.
Resurfacing the head is easy and would be worth the time spent.

Agreed. I will get it pulled and throw a new head gasket and get eyes on the condition of the inside.

 

[evinrude2323]

 

[evinrude2323]

Good strong blue spark on all 3 plugs.

 

[saltchuckmatt]

In picture 6....front of carbs, why are the choke plates closed?

 

[evinrude2323]

In picture 6....front of carbs, why are the choke plates closed?

Not sure- there is a bar that toggles them open and shut- should they be open?

 

[saltchuckmatt]

Lol....
Yes, might be your issue!

 

[evinrude2323]

Lol....
Yes, might be your issue!

Hahaha i said I was decently mechanically inclined. I didn’t say that I wasn’t an idiot however. Just flipped it and the things running like a top lol

 

[evinrude2323]

Does that need to remain open always? And why or how did that switch get flipped? It didn’t big when I gave it a little gas either. Wow I really can’t believe it if that is the issue. Guy I bought it from said it just happened to him out of the blue so he sold it for super cheap. It feels too good to be true… like there might be something else