83 johnson 140 broke piece in powerhead

[DealBrkr]

Having trouble locating a piece located underneath the inner exhaust manifold that is bolted to the block. The function of it seems to direct exhaust into the manifolds smoothly, one for each side of the motor. Right side is broke. Can't find it on any parts breakdown. Noticed a water leak coming from the manifold is how I found the piece inside broke. It was obviously already broken when I bought the motor, only had it for this one summer and has been running fine except at idle. Would have a sneeze come out of the right hole on the back of the motor where exhaust comes out above the water line. Also could this water leak inside the motor cover cause me to receive a powerful shock at the controls because it felt like I stuck my hand in a 220 outlet when this happened

 

[emdsapmgr]

Re: 83 johnson 140 broke piece in powerhead

The exhaust filler blocks are not shown on th early blocks. They were considered part of the powerhead. Later parts lists for the 110/115 hp engines show a filler block replacement kit, which comes with all the hardware: blocks, bolts and keepers. Part number: 392000. If one of those blocks is out of alignment or broken, you could get water leaks, including into the bottom cylinder(s). If you replace either/both of those filler blocks, you will have to have the back (exhaust) of the block decked to make sure it is perfectly flat prior to reassembly. It is possible that one of your coils/wires is shorting to ground on the block. That could give you the shock you describe. Try running the engine at night in a dark area and see if you have any arcing to ground in the ignition system.

 

[Haffiman]

Re: 83 johnson 140 broke piece in powerhead

The only thing that might give you a 220V shock at the controls is a shorted stop circuit (black/yellow) wire. Test by removing the black/yellow wire from the power packs and see if it goes away. Have even seen several cases where the short have been in the big red contacts between engine and remote harness.

 

[Haffiman]

Re: 83 johnson 140 broke piece in powerhead

PS:
If the shocks appear when turning off the engine, you have a broken connection in the ground wire from remote to engine.

 

[Dhadley]

Re: 83 johnson 140 broke piece in powerhead

On a V4 you can remove those filler blocks and it'll run fine. In some cases you might pick up 50 -100 rpm. If you do replace them you'll have to have them machined to make sure they are even or slightly below the gasket surface. Most likely the one was melted and then broke. The other one is probably warped or twisted out of shape too. That may have been to lugging which causes excessive combustion temps.

As for the controls, look for a loose, broken or missing ground wire in the control box itself.

 

[DealBrkr]

Re: 83 johnson 140 broke piece in powerhead

Wow thanks a lot guys. The side that broke did look melted in spots almost like someone took a tig rod to it. As far as the shock goes when it all happened the engine was cutting out real bad almost like the safety stop was acting up. So I fiddled with it while cruising down the river and if I held pressure in a certain spot it stopped but was really hard to hold in one spot. I live in Vicksburg MS so was on the Mississippi with some pretty big waves kicking last weekend from the barges. So then I took the control apart while everybody was fishing. Took the ground loose that the safety switch and everything grounds to on the case. This was the first time I got shocked testing the connection for a good ground while cranking on the engine. I was like wow and was just gonna mess with it when I got home but then on the way back to the landing at letourneau almost didn't make it. She kept going from full power to about 1500 rpms and then just fell off to 1500 coming back up river wasn't good. Soon as about to pull up to the landing with the throttle pegged out and only 1500 rpms I got lit up like nothing ever before. Now here I am and you guys have been really helpful with everything. Thanks again and anymore ideas will be really appreciated.

 

[boobie]

Re: 83 johnson 140 broke piece in powerhead

I was always told by OMC that if you ran a cross v-4 without the filler blocks you could burn a piston. On the cross v-6 it would run and not burn pistons but maybe a little down on power.

 

[Dhadley]

Re: 83 johnson 140 broke piece in powerhead

Nope, won't hurt a thing. In fact the V4 will pick up a little rpm, maybe 50 to 100 below 6000. At over 6500 it'll gain a bit more - close to 200. The V6 will lose about 100 rpm but still runs OK. Be sure to address the excess combustion temp issue.

 

[boobie]

Re: 83 johnson 140 broke piece in powerhead

The excess combustion temp issue is what I was talking about.

 

[Haffiman]

Re: 83 johnson 140 broke piece in powerhead

Removing the filler blocks you will loose some exhaust back pressure which might lean out the mix. Check the sparks after a quick run, and it might be needed to increase your main jets one size to compensate. This depends a bit of engine condition and compression. The sometimes slight increase in rpms that some people experience is the same as what happens just when you are running out of fuel, a lean condition.

 

[boobie]

Re: 83 johnson 140 broke piece in powerhead

Agreed X 2.

 

[DealBrkr]

Re: 83 johnson 140 broke piece in powerhead

Lean is mean but I understand what it can cause. I got a 91 foxbody with a 331 and 9#s of boost(lots of blown headgaskets). Rather than spend the money on the plates and getting the block decked Id rather battle fuel mixture and see where she is at. Thanks for the the heads up fellas.