1985 Evinrude 140 fuel hose sizing

Hi guys. Ive got an old 85 140 looper that came with used boat I've got. I have not had the boat on the water yet. The hoses under the cowl are different sizes and are automotive hoses. I'd like to replace them with coast guard approved hose. In its current setup it has 5/16 to the inline filter. Then 5/16 from filter to the vro. The hose feeding the carbs is 3/8 (which seems to large cause it's very loose on the vro nipple) Also, the pulse hose is 3/8 and again seems far to big for the nipple. I just went through the oem manual and it does not provide hose sizing. Just part numbers. Does anyone know what size hose should be under the cowl?

You should be able to push the 5/16 on the 3/8 fittings just heat the end with a cigarette lighter first to get it warm. Fuel line is fuel line as long as it has the braided core it will work just fine all the new dtuff is formulated for ethanol fuel.

Thanks for the response. I'll use 5/16 hose. My concern was possibly starving the motor for fuel causing a lean state and burning up pistions and the power head. Yea, I'm all doom and gloom sometimes haha.

Is the fuel nipples 3/8 in and out of the VRO? Cant you just get 3/8 fittings for the filter and just use 3/8 all the way? That being a large V-4 it wouldnt hurt. Just remember fuel flow is only as good as the smallest fitting. Is it 3/8 coming out of the tank and at the primer bulb as well. Racer would know better on if 5/16 is adequate volume for the 140hp?

Not sure the nipples are 3/8. 3/8 hose is very loose on the nipples. 5/16 is snug. it is for sure 3/8 from the tank to the primer ball. It's 3/8 right up to engine.

You can never be too careful or cautious. Check the color of the spark plugs regularly and keep close tabs on oil usage. If you have any doubts the oiler is not working properly just premix a full tank of gas and top the oil reservoir off. Put a mark on the reservoir and then run out at least half a tank of fuel. Note the amount of fuel it takes to fill it back up and convert that to ounces. Then measure how many ounces it takes to top the oil tank back up to the line. Then divide oil into fuel and it should be close to 50:1. Then you can monitor oil usage per tank of fuel fairly accurate by eyeball. If the spark plugs come out powdery white your running too lean on fuel the insulators should be a toasty brown.