Saw another way to convert from 2 line Pressure tanks.

[F_R]

Re: Saw another way to convert from 2 line Pressure tanks.

It is my unofficial guess that it is the Sierra 18-7553 or it's BRP counterpart, whatever # that is. At least that's what I'm seeing in the Sierra picture. That one appears to have the small diameter outlet nipple required to match up with the carburetor hose. The look-alike for the bigger motors has a thick nipple for 5/16" hose. Not that it couldn't be made to work by some creative engineering. But why make it difficult?

 

[jay_merrill]

Re: Saw another way to convert from 2 line Pressure tanks.

No matter what it is, or isn't, we all know that it is a three line fuel pump and we know that they are still around. I liked the info that the 30hp bypass cover is a bit different than the 35hp bypass cover because I didn't motice that at first - the lack of a mounting point is obvious but the subtle shape difference isn't. My basic point here is that we all trade information and sometimes we have something exactly right and sometimes we don't. In the end, however, I think everyone benefits.

 

[cc67]

Re: Saw another way to convert from 2 line Pressure tanks.

I have a 67 FD21 Johnson 20hp parts motor that still has the fuel pump mounted to the side plate. Can I swap this to my 58 Evinrude without any mods besides the plumbing?

 

[tashasdaddy]

Re: Saw another way to convert from 2 line Pressure tanks.

not necessarily. this is another thread on the subject.

http://forums.iboats.com/showthread.php?t=205628

 

[F_R]

Re: Saw another way to convert from 2 line Pressure tanks.

Actually, it boils down to whether or not your 35 has the mounting bosses on the bypass cover. If it does, they can be drilled and tapped and the pump will bolt right on. Some covers have the bosses, some don't. You just have to looksee. The 40 hp covers will fit the 35. Again, some have the bosses, some don't.

 

[tashasdaddy]

Re: Saw another way to convert from 2 line Pressure tanks.

mine did and i bought another one, so i have a extra, if i ever want to go back to original.

 

[jay_merrill]

Re: Saw another way to convert from 2 line Pressure tanks.

I have two 35hp bigtwins. The first one had been converted with a three line pump by tapping one bypass cover for the suction/pressure pulse and mounting the pump on the other. I changed that by mounting a stock two line pump on a later model 33hp bypass cover, which replaced the upper cover in the motor. The second Bigtwin was coverted by drilling/tapping the original, upper bypass cover and mounting the pump upside down, as shown in recent pics that I think TD published here.

BTW, TD - when I first gave you my description of how I did this I lapsed in memory, thinking that I had put the pump on the lower BP cover. As I guess you found out, it has to be on the upper cover. Chalk this up to memory loss due to "old age!"

 

[jay_merrill]

Re: Saw another way to convert from 2 line Pressure tanks.

Here are two pics showing the ways that I added a fuel pump to my Bigtwins.

In the first photo, the pump is mounted to the original, upper bypass cover in an upside down position. When using the stock bypass cover, it must be done this way to avoid hitting the throttle control rod (just under flywheel) because the previously unused mounting bosses are very slightly higher than those on the later model bypass covers.

The second photo shows my other motor with an upper bypass cover off of a 33hp Johnson. The pump is mounted as it would be on the 33hp and if you look at the top of the pump and the throttle control rod, you will notice that the pump barely clears the rod.

 

[jay_merrill]

Re: Saw another way to convert from 2 line Pressure tanks.

It has come to my attention that at least one person is not seeing the photos that I included in the above post. I used the "insert image" icon to link photos that I have at Photobucket and I can see them just fine from my computer. This is true whether I am logged in to iboats or not.

Is anyone else not able to view the images?

 

[samo_ott]

Re: Saw another way to convert from 2 line Pressure tanks.

I don't see any images either. You sure you posted em?

 

[jay_merrill]

Re: Saw another way to convert from 2 line Pressure tanks.

I'mm looking at them right now. I'll edit - delete and relink.

OK, just relinked. Do you see them now?

 

[wbeaton]

Re: Saw another way to convert from 2 line Pressure tanks.

I see them. Looks like a quality job. Much nicer finished appearance than the one TD found and posted.

 

[tashasdaddy]

Re: Saw another way to convert from 2 line Pressure tanks.

"In the first photo, the pump is mounted to the original, upper bypass cover in an unsidedown position. When using the stock bypass cover, it must be done this way to avoid hitting the throttle control rod (just under flywheel) because the previously unused mounting bosses are very slightly higher than those on the later model bypass covers."

that's the way i did mine, upside down, due to clearance. and was too tight
to get it on the bottom one.

 

[samo_ott]

Re: Saw another way to convert from 2 line Pressure tanks.

I see em now! weird.

 

[jay_merrill]

Re: Saw another way to convert from 2 line Pressure tanks.

Your absolutely right, TD. I made these conversions quite awhile ago and had forgotten that I put the upside down one on the upper bypass cover. If I remember correctly, you can't put them in either direction on the lower cover because the pump will hit the cowling. I suspect the same thing would be true of the Johnson cowling.

One point of interest, too, is that I like the way you ran the hoses on yours better than the way I did mine. I try to keep fuel lines away from electrical wires as much as possible so I am going to rotate the inlet cover and run both hoses in a forward direction to get them away from the spark plug wires.

And, just becaiuse I had forgotten about it and didn't notice until I looked at these pics again, if anyone is wondering what the red wire around the sparkplug wire is for, its the sensor wire for a Tiny Tach tachometer.