Using Mercruiser Manifold on Yamaha 3.0L L4

My mani and riser are shot, so I'm going the route of a Mericruiser mani. From what I understand, an angled riser would give me a better shot with lining up with my exhaust, and I have to get a mercarb.

A couple questions.

I came across a thread mentioning having to run additional plumbing for water when someone was doing this on a 6 cylinder I believe. Would I have the same issue with my 4 cylinder?

Are there any mercruiser manifolds that would accomodate my rochester carb?

Heres a pic of my current mani


I found 2 diff styles of manifolds that look similar to what I have

The 2.5L 120 hp / 3.0L 140hp R/MR/Alpha pt # 1860235A04
http://www.mercruiserparts.com/Show...D+AND+WATER+SYSTEM+(USE+W/1+PIECE+EXH.+ELBOW)
120 H.P./2.5L140 H.P./3.0L R/MR/ALPHA
3.0L / LX Alpha one engine pt# 860235A03
http://www.mercruiserparts.com/Show...ANIFOLD+AND+WATER+SYSTEM+(ONE+PEICE+MANIFOLD)

which one of these manifolds would work with my application?

Re: Using Mercruiser Manifold on Yamaha 3.0L L4

which one of these manifolds would work with my application?

Click to expand...

Ayuh,... It could be Either,...
Or,..
It could be Neither....

You're cobbing things together, not replacin' like for like....
The only real way to know is to Try it...

If you contact Capt. Ken at www,nelsonmarine.com, He might possibley Know, or be able to tell you where to get the Right parts...

Re: Using Mercruiser Manifold on Yamaha 3.0L L4

Bond-o said:

Ayuh,... It could be Either,...
Or,..
It could be Neither....

You're cobbing things together, not replacin' like for like....
The only real way to know is to Try it...

If you contact Capt. Ken at www,nelsonmarine.com, He might possibley Know, or be able to tell you where to get the Right parts...

Click to expand...

youre right. But these manifolds and carbs are way too expensive for me to buy just to try. Id rather make as educated of a decision as possible as opposed to just throwing even more money towards a lost cause. We're already 3k+ in the hole

Re: Using Mercruiser Manifold on Yamaha 3.0L L4

Ayuh,... The Best I can tell you is,... The exhaust/ motor side will bolt up No Problem...
Now,...
Whether there's the proper drillings for brackets or other accessories,...
Muchless whether the riser will line up with the downpipe,...

I Donno, but rather Doubt it...

email Capt. Ken....

Re: Using Mercruiser Manifold on Yamaha 3.0L L4

the riser and downpipe will not line up. I currently have the yammie 3.0 in my boat, and i also have a mercruiser marinized 3.0 on standby. the riser bolt pattern is different. I think that the downpipe will have enough movement in it to pull over and attach. You may need to fudge things a bit, new rubber hose, maybe shorten the downpipe a few inches so you can add longer rubber hose which would give you more flexibility. I have thought a little bit about doing this in the future also. I have no doubt that it can be done, you just need to be creative.

Re: Using Mercruiser Manifold on Yamaha 3.0L L4

ricovw said:

the riser and downpipe will not line up. I currently have the yammie 3.0 in my boat, and i also have a mercruiser marinized 3.0 on standby. the riser bolt pattern is different. I think that the downpipe will have enough movement in it to pull over and attach. You may need to fudge things a bit, new rubber hose, maybe shorten the downpipe a few inches so you can add longer rubber hose which would give you more flexibility. I have thought a little bit about doing this in the future also. I have no doubt that it can be done, you just need to be creative.

Click to expand...

Very true, im not concerned about the riser/downpipe issue, as i have to replace the riser as well. As far as I could remember, the only things bolted to the mani was the throttle cable and the alternator, but I can find a way to make that work, that too not being a concern for me.

My main concern is a mericruiser manifolds compatibility with the yammie head.

Re: Using Mercruiser Manifold on Yamaha 3.0L L4

My main concern is a mericruiser manifolds compatibility with the yammie head.

Click to expand...

?? Ayuh,... They're Both 3.0l Chevys....?? The Same Exact motor...

Re: Using Mercruiser Manifold on Yamaha 3.0L L4

Were yiu able to find a manifold for the Yamaha 3.0L L4? I have a crack in my 92 Yamaha manifold and am looking for the part.