Help needed with pump on OS FS 120
#1
Thread Starter
My Feedback: (1)
Help needed with pump on OS FS 120
I have recently acquired an OS FS 120 4 stroke w/ pump. On the face of the pump are three fittings. The fittings labeled IN and OUT are no-brainers, but I am not sure what the 3rd one is for. I think it is labeled D (not sure), but what is it's pupose, and does it need to be plugged, vented, or what? I have looked on the OS webpage, but I cannot find a manual for this particular engine. I did find out that it has a shorter prop shaft than the current OS 120 4 strokes, so if you are planning on using Tru-Turn or similar spinners, their normal adapter bolts will not work. If any one knows this information, please let me know. Thanks, Andy
#2
Senior Member
Join Date: Sep 2002
Location: Oslo, NORWAY
Posts: 1,579
Likes: 0
Received 0 Likes
on
0 Posts
RE: Help needed with pump on OS FS 120
I had the classic 1.20 SurpassII with pump.
Could well be the same.
You have the "in and out" nipples at 3.00 & 9.00 oclock. I cant' remember which was which... and then a "third" nipple at say 4.30.
Right. The "in" nipple is fuel in from tank.
The "out" nipple is fuel return to tank. Thats right, a line that goes back to the tank.
The "third" nipple at 4.30 is the line out to carb.
Under the carb on the right hand side there's a connection nipple.
You need a 3cm piece of fuel tube to connect the two.
Could well be the same.
You have the "in and out" nipples at 3.00 & 9.00 oclock. I cant' remember which was which... and then a "third" nipple at say 4.30.
Right. The "in" nipple is fuel in from tank.
The "out" nipple is fuel return to tank. Thats right, a line that goes back to the tank.
The "third" nipple at 4.30 is the line out to carb.
Under the carb on the right hand side there's a connection nipple.
You need a 3cm piece of fuel tube to connect the two.
#5
Thread Starter
My Feedback: (1)
RE: Help needed with pump on OS FS 120
Yep, there are 3 nipples - #1 IN #2 OUT #3 R. I found an article that says the IN is from the fuel line (clunk) in the tank, the OUT goes to the carb, and the R goes to a third line on the tank, like a vent but instead of angling up, it is angled down to the bottom of the tank. I guess the pump pumps too much fuel, and this is how excess gets back to the tank, instead of dumping it over the side. The vent line on the tank has to be completely vented, no plug, so that the tank doesn't over-pressurize. What is strange here is that when I bought this engine, in between the OUT and the carb, in the fuel line, there is a piece of brass rod with a very small hole drilled in it. I am sure it is a restrictor, but does it restrict pressure or amount (or both)? Thanks for all of your help.
Andy
Andy
#6
My Feedback: (11)
RE: Help needed with pump on OS FS 120
On the FS-120 Surpass I And II engines, the nipples are this:
"IN"---From fuel tank to pump.
"OUT"---From pump to carburetor
"R"---Return line back to tank
Here's how to adjust your carburetor:
http://www.osengines.com/faq/faq-pumped.html
For the instructions, you can send an email to the address listed below. The FS-120 Surpass I has a large brass screw in the center of the pump. The FS-120 Surpass II has no screw on the pump, but does have a long velocity stack on the carburetor. The carbs are different, so the instructions are different. If you email for the instructions, please let us know which engine you have.
"IN"---From fuel tank to pump.
"OUT"---From pump to carburetor
"R"---Return line back to tank
Here's how to adjust your carburetor:
http://www.osengines.com/faq/faq-pumped.html
For the instructions, you can send an email to the address listed below. The FS-120 Surpass I has a large brass screw in the center of the pump. The FS-120 Surpass II has no screw on the pump, but does have a long velocity stack on the carburetor. The carbs are different, so the instructions are different. If you email for the instructions, please let us know which engine you have.
#7
Senior Member
Join Date: Sep 2002
Location: Oslo, NORWAY
Posts: 1,579
Likes: 0
Received 0 Likes
on
0 Posts
RE: Help needed with pump on OS FS 120
I went to the garage and got ou the ol' SII.
Just go over this again:
Nipple at 3.00 oclock=fuel in (marked in)
Nipple at 4.40 oclock= fuel to carb (marked out)
Nipple at 9.00 oclock = fuel back to tank (not market on mine)
Just go over this again:
Nipple at 3.00 oclock=fuel in (marked in)
Nipple at 4.40 oclock= fuel to carb (marked out)
Nipple at 9.00 oclock = fuel back to tank (not market on mine)