1985 Mercruiser 140 replacement manifold bolt pattern

[Whisky Charlie]

1985 MCM 140 Serial No. OA343460.

Bought a new manifold from the dealer. The receipt shows Part Number 860235A04. There are two problems:

1. The bolt pattern and ports match up to the block except that the new manifold does not have a hole for one of the mounting bolts (the second one forward from the riser.)

2. The new manifold has freezeout plugs with raised bosses which keep the shift bracket from laying flat on the manifold. (The original manifold had no freeeout plugs or bosses.) The bracket mounts on two of the manifold mounting studs and will lay flat if two washers are put on each of the two studs under the bracket.

Does anybody know why they left out the missing bolt hole, and if the gasket is likely to leak?
Any problem with using two washers, the shift bracket then the nut on the manifold mounting stud?

As usual, thanks for your help and advice!

 

[achris]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

1985 MCM 140 Serial No. OA343460.

Bought a new manifold from the dealer. The receipt shows Part Number 860235A04. There are two problems:

1. The bolt pattern and ports match up to the block except that the new manifold does not have a hole for one of the mounting bolts (the second one forward from the riser.)

2. The new manifold has freezeout plugs with raised bosses which keep the shift bracket from laying flat on the manifold. (The original manifold had no freeeout plugs or bosses.) The bracket mounts on two of the manifold mounting studs and will lay flat if two washers are put on each of the two studs under the bracket.

Does anybody know why they left out the missing bolt hole, and if the gasket is likely to leak?
Any problem with using two washers, the shift bracket then the nut on the manifold mounting stud?

As usual, thanks for your help and advice!

Don't know, no and no...

Chris...

 

[Grub54891]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

Can't tell ya either,but I may be replacing mine in the spring.I have a very small water leak right in the middle wher I cant see between the block and manifold,right in the middle,under the carb.seen it before,the weak spot! I'd like to see some pics of the old and new to see whats going on.They probbaly changed the design a bit.
Grub

 

[achris]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

Can't tell ya either,but I may be replacing mine in the spring.I have a very small water leak right in the middle wher I cant see between the block and manifold,right in the middle,under the carb.seen it before,the weak spot! I'd like to see some pics of the old and new to see whats going on.They probbaly changed the design a bit.
Grub

There are NO water passages between the manifold and the head (or block for that matter) the only way water gets into the manifold is through the small hose on the front of it.

 

[Whisky Charlie]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

Will try to work up some pics over the weekend. Concerning your water leak, some of the manifold mounting bolt holes are drilled right through into the block water jacket. The new bolts and studs come with sealer on the threads. Seems unlikely they would leak water, but who knows? How about a freezeout plug?

 

[ONEGA]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

A friend of mine had a hard time finding a manifold for his 4 banger about the same vintage, he had to return 3 of them because of the same problem.
He ended up looking on CL for used ones trying to match numbers on his old manifold and elbow. It took him 6 months to find what he was looking for.

 

[Grub54891]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

The coreplugs arent leaking,no water in the oil, run's great,120 compression. Just haven't checked any further. I have seen a couple crack right in the middle,not saying it would cause the water leak but it is coming from someplace,maybe even the head gasket. The leak has stopped but the boat sat for 6 years before I acquired it. Anyway,don't want to hi-jack the thread,just would like to see what the differences are between the manifolds for future reference. If nothing else,I'd have it machined or figure out spacers to make the bracket fit. That is only if no replacement is available anymore.
Grub

 

[achris]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

Will try to work up some pics over the weekend. Concerning your water leak, some of the manifold mounting bolt holes are drilled right through into the block water jacket. The new bolts and studs come with sealer on the threads. Seems unlikely they would leak water, but who knows? How about a freezeout plug?

The manifold mounts to the head, not the block. And the bolt hose should not be passing into any water jacket. Head bolts into the block, yes, straight into the water jacket, hence the need to use a sealer on the threads.

Chris......

 

[Whisky Charlie]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

I have Emailed Mercury Marine asking about the part number and the bolt pattern. Will post whatever they say, if anything. As to the water jacket thing, I was running a tap into the mounting bolt holes before installing the manifold and the tap went right on through into the head and I assumed water jacket without thinking. Could be intake or exhaust passage or whatever.

 

[fishrdan]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

Sounds like you have a manifold/head mismatch. I ran into the same problem 10 years ago, manifold looked really close, but didn't have all the right bolt holes,,,, and the ports had minor differences. There are several different heads and manifolds used on GM 4 cyl marine engines over the years. Some of the manifolds do not have the mounting holes/bosses for the side mounted throttle cable as it wasn't needed in later years.

Mercury/Mercruiser may have superceded the old manifold to a newer manifold that works with "most", but not yours. OR, maybe they gave you the wrong manifold. I bought a Barr manifold this summer that was an exact replacement for my 73 Mercruiser 140HP, fit perfect.

Post up pics of the old and new manifold, and of the engine's head port configuration.

 

[Whisky Charlie]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

MerCruiser Customer Service advises that I have the correct manifold part number. They say that when they redesigned it they decided the sixth bolt was not necessary and the five bolt manifold should work fine on my engine.

I wonder how many of these five bolt manifolds are installed and "working fine." Next year when we are out on the bay with the tide running out fast to the ocean, I will tell myself not to worry, MerCruiser says it's OK.

 

[achris]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

MerCruiser Customer Service advises that I have the correct manifold part number. They say that when they redesigned it they decided the sixth bolt was not necessary and the five bolt manifold should work fine on my engine.

I wonder how many of these five bolt manifolds are installed and "working fine." Next year when we are out on the bay with the tide running out fast to the ocean, I will tell myself not to worry, MerCruiser says it's OK.

Plenty.... I've installed a few myself and haven't had any problems...

Chris........

 

[AgnotGt]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

I just replaced the manifold on my 120 (2.5l) and had a issue with the manifold (860235A04) being different to the point of unusable. Wrong port size and wrong exhaust pad for the elbow. I got the correct one from Barr's Marine. You might give them a call. Here is my post: LINK to for more info. My original manifold had 5 bolts and the replacement had six. The head had six so I added a bolt. That part number was MC-1-99798

MerCruiser 860235A04 was the last "one size fits all" replacement that doesn't.... imo

Hope you get it worked out! Glenn

.

 

[thumpar]

Re: 1985 Mercruiser 140 replacement manifold bolt pattern

I just replaced the manifold on my 120 (2.3l) and had a issue with the manifold (860235A04) being different to the point of unusable. Wrong port size and wrong exhaust pad for the elbow. I got the correct one from Barr's Marine. You might give them a call. Here is my post: LINK to for more info. My original manifold had 5 bolts and the replacement had six. The head had six so I added a bolt. That part number was MC-1-99798

MerCruiser 860235A04 was the last "one size fits all" replacement that doesn't.... imo

Hope you get it worked out! Glenn

.

Just to be clear the mercruiser 120 is 2.5l.