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Mercury 25HP Gas Line Size

R

rmcderm313

Regular Contributor
Hi Folks,

Does anyone know what line size the gas lines are that go from the fuel connector to the fuel filter, and then from the filter to the catb 0n a Mercury 25HP serial number 0B236965?

Thanks,
Rob
 
Graham, is there any reason not to buy a couple of feet of 8mm gas line and cut those two parts to size? Instead of buying the specific parts from Mercury at $60 each??????

Thanks as always for your quick response..
Rob
 
I buy my gas line from a discount auto place - sell it by the foot (as does West Marine at double the price which is still about 1/10 th the cost of OEM).

Just make sure you get gas line that is "alcohol friendly" (which most is today).

If you do opt to change the fittings as suggested here you may opt to move up to the 3/8" gas line - flows better/less restriction, fuel pump don't work as hard (which extends the life of the diaphragm) - no down side unless you are leaving the original fittings/barbs in place...
 
Graham, I think you might have misunderstood what line I'm referring to. I'm referring to the lines inside the cowl, like this one..

photo 1 (10).jpg

I just got a digital caliper and it looks to be .25" (6.36mm) IM.

photo 2 (10).jpg

and .473" (12.01mm) OD.

photo 3 (5).jpg

Does that sound correct? I just want to make sure the calipers are correct, they were pretty cheap...

Looks like this would be a good replacement...

http://www.grainger.com/Grainger/Fuel-Hose-5RLZ8?cm_sp=IO-_-IDP-_-RR_VTV70300505&cm_vc=IDPRRZ1


Thanks,
Rob
 
Last edited:
looks like you got the part and hose out ...take it with you to the store...it should be a tight fit....if you rely on the clamp to tighten a loose fit then it will leak...
 
I'm still thinking I use 3/8" hose (might be 5/16") - I believe you are getting a 1/4" inside diameter due to it being (crimped) onto the fitting by the hose clamp/zip tie.
 
You may have the 1/4" line. As you get up in hp I know you use 5/16 and on up in hp 3/8. Varies by engine mfgr., hp, and location in the fuel system.

Mark
 
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