Newbie Here, Need some engine help... Please... 77' Johnson 35hp

[castires]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

Can you explain where you see discoloration? I want to know what to look for. To me it all looks the same... But I really don't know what to look for...

The motor never seized, it continued to run, I shut it down once I saw it was overheating. It also started right back up. In my experience (Automobile) if the motor seizes, everything stops working...

No, I'm not seeing the smoke come from inside the cover, you can see it clearly in the video what I'm referring too.

I will order a new head gasket tomorrow and install it this weekend.

As far as tightening the bolts to spec, the lower cover doesn't appear to be able to be dropped to allow full access to the lower head bolts. Is there a trick or secret I'm unaware of? There's no way my inch/lb torque wrench with a socket will fit down in there.

Thanks for everyone's help, I'm really impressed with the response I've had.

 

[F_R]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

You are the one that told us that the compression is uneven. We didn't make it up. As I said, maybe you got lucky and shut it down in time. Most people brought them in after they were thoroughly fried. I really can't decide what to say about the paint. Anyhow, it would seem that it has had a rough life before you got it, so we really can't tell what happened, when.

Sometimes you have to guess at the torque. Not good, but whatta ya gonna do?

It is supposed to smoke, especially in a barrel. But as you yourself said, you squirted oil in it. That will make it smoke more and make more gunk on the water.

 

[castires]

Thanks for the info FR,

So is everyone in agreement that I should replace the head gasket?

If so, any tricks to torque the lower bolts?

 

[jasper60103]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

Thanks for the info FR,

So is everyone in agreement that I should replace the head gasket?

If so, any tricks to torque the lower bolts?

I can't see the lower head too well in your video, but when I replaced the head gasket on my '88 J30 hp, the lower head bolts were more difficult to reach, but certainly doable. I used a 3/8 socket style torque wrench. If all else fails, just guess as F_R suggested.

http://www.amazon.com/Neiko-8-Inch-...53ZE/ref=sr_1_1?ie=UTF8&qid=1323229965&sr=8-1

 

[Joe Reeves]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

Okay... you're speaking of smoke pertaining to exhaust, not heat. What I saw exiting the engine, taking into consideration it's running in a barrel, wouldn't concern me.

The 15 psi difference in compression does concern me however, and that would be my starting point if I was working on the engine. I've seen many mechanics install water pumps and do other tune up work etc only to find that a serious compression problem existed (broken piston ring, etc). I'd want to see what's in there first off.

Those bottom bolts.... there a special offset tool to torque them on most engines (yours?). Torque what you can and tighten the bottom bolts by feel as good and as close as possible. Works for me.

The discoloration? That engine is normally pure white... it was just that I thought the head and the related portion of the crankcase looked something other than white, a color usually associated with heat.

 

[castires]

From what I can tell, it looks like he had it painted. But I could be wrong.

He works weird shifts and I haven't been able to get a hold if him.

My plan today when I get off work is to pull the head and inspect it, the cylinders, etc.

I'll post pics of everything as soon as I get them off.

To check the rings, assuming they're not obviously broken, should I use a feeler gauge and check the gap(s)?

 

[Home Cookin']

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

I'm thinkiong the heat damage came not from your mishap but from your friend's, before he rebuilt it. If he machined the head and bores, that's the big clue.
Who knows if he broke it in right (double oil, varied speed, etc) or if he really got it up to the problem zone. If I had to bet my lunch money, you are experiencing the effects from the first overheat, that only show up when you get your temps up.
But that doesn't explain your burned-up impeller--was it replaced in the rebuild?

Note I'm no mechanic so my views are amatuer guesses, though I've dealt with old, overheated and rebuilt small OMC's, sad to say.

 

[castires]

I'm fixing to head home and tear her down. Pics will be coming soon.

 

[castires]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

Ok, I got it torn apart. Pics below:

Pic of the head:

Pic of the gasket, some pin holes that I found in it. Looks like it was in the water pasage though, so not sure if that would have been a problem or not:

Pic of the top piston, looks like it was having water entering it, there is water/oil beaded up on it (Also, there is a piece of rubber as seen in the pic, one on the top and bottom. Are they supposed to be there):

Pic of the top piston wiped off:

Here are some various pics trying to show you all the cylinder walls:

 

[castires]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

 

[castires]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

I just took the gasket off the head and cleaned it up a bit. I layed it on my kitchen table (glass) and found the head is warped...Ugh...

So...Can I have the head decked? Anyone have the specs if so, so I can see if there is enough material left to have it done. Or should I just replace the head?

 

[destroyer_85_golf]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

best of luck with this motor, my dad and i had one just like it. The motor ran great until it overheated on us and locked up. the one question i have for anyone who is reading this is, you said this was a rebuilt motor. I dont see the strong crosshatches in the cylinder is it possible that when it overheated they were knocked down?

 

[castires]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

I was able to get a hold of my friend this evening. He said he sent the block and the head to a machine shop. They worked the cylinder walls, and flattened the head. I'm assuming it got hot in the past and warped... Though he didn't say that.

He replaced the pistons/rings/bearings/gaskets, etc... He said he used the book he gave me to do it all.

His suggestion was to take the head to the machine shop and have them flatten it and then install a new head gasket and see what happens.

Does this sound like a good plan? Should I try and find a new head?

 

[jasper60103]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

I was able to get a hold of my friend this evening. He said he sent the block and the head to a machine shop. They worked the cylinder walls, and flattened the head. I'm assuming it got hot in the past and warped... Though he didn't say that.

He replaced the pistons/rings/bearings/gaskets, etc... He said he used the book he gave me to do it all.

His suggestion was to take the head to the machine shop and have them flatten it and then install a new head gasket and see what happens.

Does this sound like a good plan? Should I try and find a new head?

Good pics. FYI, the rubber tubes are called water diverters and supposed to be there.

Looks like you found a blown head gasket and some scoring on the cylinder wall. Can you feel it with your finger nail?

Well, here's a cylinder head (#319407) on ebay for $50. Can you have yours machined for less? Also, here's a thread on a rebuild on your motor (for different reasons), but thought it may interest you. Keeps us posted. http://forums.iboats.com/showthread.php?t=391984

http://www.ebay.com/itm/Johnson-Evi...945636&pt=Boat_Parts_Accessories_Gear&vxp=mtr

 

[castires]

My fingernail doesn't get caught on the scoring, but it us a difference from the rest of the cylinder walls. Rubbing it with my finger tip, I feel no difference.

 

[F_R]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

Ok, my opinion is, "nuff said". That first picture of the cylinder wall clearly indicates scoring. How much it is scored, I can't say. But you can bet your boots the piston and rings are scored.

Also, the water. It is getting in there somehow. Possibly the head gasket, or even more likely the exhaust cover gaskets. Did your friend even remove and check the exhaust covers? But even if he did, they are burned up again from recent overheating. You just can't overheat those motors without doing damage, as you witness from the warped head.

 

[castires]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

Ok, my opinion is, "nuff said". That first picture of the cylinder wall clearly indicates scoring. How much it is scored, I can't say. But you can bet your boots the piston and rings are scored.

Also, the water. It is getting in there somehow. Possibly the head gasket, or even more likely the exhaust cover gaskets. Did your friend even remove and check the exhaust covers? But even if he did, they are burned up again from recent overheating. You just can't overheat those motors without doing damage, as you witness from the warped head.

So are you saying I should just throw in the towel?

 

[castires]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

If I did the following, do you think it would survive another year or so? This isn't the boat/engine that I want to end up with, but it's a good little fishing boat, or should I say was. I'd like to keep the cost to a minimum and save up for a nice used flats boat.

1.) Resurface the head or purchase one
2.) Replace the head gasket
3.) replace the exhaust gaskets

 

[F_R]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

That's your decision to make. I told you up front that is a bad motor for Florida. Maybe somebody "Up North" with their pristine waters may be interested in it??

BTW, OMC 35hp motors were OK after they moved the water intake to the sides of the gearcase. I have one and consider it to be one of the best motors I've ever owned.

 

[castires]

Re: Newbie Here, Need some engine help... Please... 77' Johnson 35hp

Thanks for your help F_R!

I guess it's decision time.

I think I'll just do what I stated above and hope for the best. If she dies again, then I will get another motor. What would you recommend as a replacement?