Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine?

[cecho]

It'll bolt into place, but is there any problem using it?

I have a brand new in the box one lying around, should I keep it for parts on my 898 or sell it?

It's a mechanical fuel pump for an 305 OMC cobra

 

[Bondo]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Ayuh,...... What the 'ell is a 18-7268,..??

We're supposed to go search up some part number to answer yer question,..??

The Idea here is, YOU do the leg work to pay for yer Free answers.....

 

[cecho]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Well, apparently that line of text got deleted from my post during editing at some point. The part is staring me right in the face. Why would I need someone to tell me what it is? :lol: I KNOW I put the term MECHANICAL FUEL PUMP on there at some point. I even remember spelling the word mechanical wrong and having to correct it.

That part is a mechanical fuel pump for an OMC Cobra. I want to know if it'll work for my 898.

 

[Don S]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Find the Sierra number for your 898 and see if they are the same number.

Look just above and to the right of your original post, click on the fuel system parts icon and follow the links.

 

[cecho]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

They are not the same, but isn't a fuel pump a fuel pump? The only difference I see is the one for my boat has the bottom rotated a bit. I don't see any problem with rotating it to the proper orientation or just moving the fuel lines a bit, but I'd like to hear an opinion on that.

 

[HT32BSX115]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Ayuh,...... What the 'ell is a 18-7268,..??

We're supposed to go search up some part number to answer yer question,..??

The Idea here is, YOU do the leg work to pay for yer Free answers.....

Yeah. We usually shouldn't have to tell somone how to do a simple google search but here it is:

http://www.iboats.com/OMC-Sterndriv...0451844--session_id.483432049--view_id.268928

Replaces: 981650
Flange I.D. #41415
For: GM (V-8) 305, 307, 350, 400

Product Description

AC Mechanical Fuel Pump Fits GM V8 engines Used on 305, 307, 350, and 400 cu. in. engines

From Teleflex Sierra:

18-7268 Fuel Pump - Sierra


› TeleflexSierra > › Stern Drive Parts > › OMC Sterndrive/Cobra > › Fuel > › Fuel Pumps, Kits and Related Parts for OMC Sterndrive/Cobra Stern Drives

18-7268 Fuel Pump Sale Price: $179.00 Part # 18-7268 replaces: OMC 981650 replaces: Volvo 3855276

I can "google" with the best of 'em

 

[cecho]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Yeah. We usually shouldn't have to tell somone how to do a simple google search but here it is:





From Teleflex Sierra:



I can "google" with the best of 'em

Thanks for the reply, but that doesn't answer my question. I KNOW it will fit, but will it cause any problems? Google doesn't tell me. That's always the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th and 10th thing I do before trying to search here... The search feature on iboats.com is atrocious so I generally also use google to do that (search term site:iboats.com) Last step is ask a question. This thread is step 12 in my quest for an answer. I've been doing internet research since before google existed.

 

[RogersJetboat454]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

You know it's a different part number.
If that isn't good enough for you, you can try installing it to see if it will work with what you have.
You're gunna be hard pressed to find someone on here that was in your exact situation that could tell you if it does or doesn't work.

 

[cecho]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

OK, I guess the answer I need is to the following question, "Is it possible that the OMC fuel pump has a fuel pressure output that will not work with the carb on my 898 since I know the thing will bolt up?" -AND- "Will unbolting and rotating the bottom of the fuel pump cause any problems?"

I seriously didn't think it's that difficult of a situation. It seems simple to me and I was just hoping for some kind of clarification. Missing the term fuel pump in the original post obviously was dumb on my part. :facepalm:

I thought there'd be at least one person on here that's opened a mechanical fuel pump before. :lol: If this procedure is as radical as it seems to be after posting I guess I should just sell it before it explodes. I jest of course. Thanks for any and all help.

 

[HT32BSX115]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Thanks for the reply, but that doesn't answer my question. I KNOW it will fit, but will it cause any problems? Google doesn't tell me. That's always the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th and 10th thing I do before trying to search here. Last step is ask a question. This thread is step 12 in my quest for an answer. I've been doing internet research since before google existed.

Ok,

I did a little more searching.

Here's the iBoats fuel pump link for Mercriuser.

Mercruiser Fuel Pumps - iboats

That part number is NOT in the list.

The pump you mention will PROBABLY bolt to the side of the your engine but the fittings will most likely either NOT line up with your steel fuel lines or the actual fittings will not screw into the pump.

That of course doesn't mean the pump will not work. It most certainly will. You'll just have to make up new stainless steel fuel lines.

If you have to pay someone to make up those lines, it'll likely cost you more than just buying the right pump.

OTOH,


I am going to assume it's "OK" to post images from iBoats parts.....

Here's the Sierra pump from the iBoats ad:

Replaces OEM part #

• MERCURY MARINE 861678A 1
• MERCURY MARINE 97401A2
• MERCURY MARINE 97401A8
• OMC 509404

And here's the 18-7268


Replaces OEM part #

• OMC 981650
  Flange I.D. # 41415
  For GM ( V-8 ) 305, 307, 350, 400
• VOLVO 3855276
• CRUSADER
  ( Flange I.D. #41415, M6948 )
  For: GM ( V-8 ) 305, 307, 350, 400 ( 5.25 - 6.5 PSI )

It doesn't take a Rocket Surgeon to realize that one could easily pull the screws above, and rotate the pump fitting body around to match your fuel lines.

That's what I would do if I had one laying around.

 

[cecho]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

It doesn't take a Rocket Surgeon to realize that one could easily pull the screws above, and rotate the pump fitting body around to match your fuel lines.

That's what I would do if I had one laying around.

Thanks, that's what I was planning to do, but I think rocket science is definitely easier than working on old marine equipment... All the information is readily available.

I'm wondering if the PSI on the pump might be way off or if opening it up might break some sort of seal, that's why I originally created this thread... I see now I should have clarified that, but the original question made perfect sense to me.

The fuel pressure question I can look up. The seal question I haven't had luck with.


Thanks!

 

[matt167]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

As long as the diaphram goes back togther, you should be good to go. However, replacing diaphrams and rebuilding mech fuel pumps are a PIA to get right and if the diaphram is ruptured or leaking, the gas will leak into the crankcase. If I were to use it, I would just bend up some adapter line and use that to connect to the fuel lines that are there. It will work, and you have it already

Fuel pressure should be fine for any carb. Most 4bbl's will run on a little less than 7 PSI, same with the 2bbl variations

 

[cecho]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

As long as the diaphram goes back togther, you should be good to go. However, replacing diaphrams and rebuilding mech fuel pumps are a PIA to get right and if the diaphram is ruptured or leaking, the gas will leak into the crankcase. If I were to use it, I would just bend up some adapter line and use that to connect to the fuel lines that are there. It will work, and you have it already

Fuel pressure should be fine for any carb. Most 4bbl's will run on a little less than 7 PSI

Thanks! That's exactly what I was needing to know.

 

[HT32BSX115]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

I'm wondering if the PSI on the pump might be way off or if opening it up might break some sort of seal, that's why I originally created this thread............. The seal question I haven't had luck with.Thanks!

Well, there's that risk anytime you open up a fuel pump. The pressure question is pretty easy. Since it's based on strokes per min and diaphragm size I'll bet it's the same. ( If you're worried get yourself a 0-15 psi gage and measure it. )

Most all mechanical fuel pumps were designed for carburetor use and don't put out more than 5-7 psi. It's electric fuel pumps nowadays that are designed for EFI systems and many put out more than 30psi...... (you have to use a regulator with them for carb use)

If it's a REALLY old pump, leaks could be a problem. If it's not all that old, then the diaphragm is likely still soft and pliable and shouldn't leak when you put it back together.

Don't be too aggressive taking it apart. And when you put it back together, be sure to cross tighten the screws a little at a time and don't tighten them so tight you strip the screws or squash out the diaphragm.

Some of those fuel pumps still have kits available..........and the kits are just new diaphragms.

 

[cecho]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Well, there's that risk anytime you open up a fuel pump. The pressure question is pretty easy. Since it's based on strokes per min and diaphragm size I'll bet it's the same. ( If you're worried get yourself a 0-15 psi gage and measure it. )

Most all mechanical fuel pumps were designed for carburetor use and don't put out more than 5-7 psi. It's electric fuel pumps nowadays that are designed for EFI systems and many put out more than 30psi...... (you have to use a regulator with them for carb use)

If it's a REALLY old pump, leaks could be a problem. If it's not all that old, then the diaphragm is likely still soft and pliable and shouldn't leak when you put it back together.

Don't be too aggressive taking it apart. And when you put it back together, be sure to cross tighten the screws a little at a time and don't tighten them so tight you strip the screws or squash out the diaphragm.

Some of those fuel pumps still have kits available..........and the kits are just new diaphragms.

Thanks! It's a new in the box pump. It seems like a waste to sell it for a loss and buy a new one when the only difference is a simple fix.

Also, following instructions or installing parts just because "it's the right one" isn't good enough for me. I need to know why the part is the correct one. In my experience, over half the time it's because of no good reason. I just like to understand the things I work with more.

 

[HT32BSX115]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Thanks! It's a new in the box pump. It seems like a waste to sell it for a loss and buy a new one when the only difference is a simple fix.

Just remember "New in the box" doesn't always mean "New" . It could still have a cracked and stiff diaphragm.

Once you get it apart, you'll know immediately if the diaphragm is ok.

 

[cecho]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

Just remember "New in the box" doesn't always mean "New" . It could still have a cracked and stiff diaphragm.

Once you get it apart, you'll know immediately if the diaphragm is ok.

True, but the rubber on the outside is still pliable. I'd be surprised if there was anything wrong with it inside. I'll keep it for parts instead of parting with it.

 

[Silvertip]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

There is a bit of analysis that you can do before you touch a screwdriver to those screws in an attempt to rotate the housing.

1) Are the holes evenly or unevenly spaced? That will determine if you can rotate the housing.
2) Is the internal construction such that even if the holes are evenly spaced, do the internals still line up properly. I seriously doubt anyone can that's the case and be 100% positive without looking.
3) What often looks simple and logical is not always simple and logical.
4) The 305 engine block is externally identical to the 350 so the pump will fit.
5) Both engines are carbureted so the pump pressure will not be an issue.
6) My suggestion, install the pump and relocate the lines if that's easily done.
7) If #6 is not possible then you make your choice and take your chances.

 

[wrench 3]

Re: Will Sierra 18-7268 for an OMC 305 Chevy engine work on a mercruiser Chevy engine

It was probably in the late 1960s when I last rebuilt an automotive style fuel pump. So I'm not sure of the bolt pattern but I do remember that the internal parts were concentric so rotating won't be a problem. Depress the operating lever to get the diaphragm roughly flat when re-installing and tightening the screws.