Fuel line/filter upgrade

Posts: 238

I'm replacing the inline fuel filter on my 150, and am wondering if anyone has upgraded their fuel lines to a larger diameter. Should I stick with the same 1/4" lines that are stock or go up to 5/16" for better flow? Any benefit? I'm waiting on larger main jets to install... and the new filter will have 2 stage connections for both 1/4" and 5/16". Suggestions?

Posts: 1893

I recently upgraded to 3/8" fuel lines and ended up dropping my main jet size from 150 to 140 due to the increased volume. The stock lines and filter were limiting fuel to the carburetor so I had to overcompensate with the jet until now...

Posts: 4286

I have put 3/8 line and filter with a manual fuel valve on my 250. lots better fuel flow

Posts: 238

What kind of valve do you have on there BigE...ball valve? I would think that would only add to my confusion when I'm trying to find the right mix of fuel/air after I rejet. Then again... it might allow me to adjust the fuel flow a little easier then taking apart the carb every time to change jets. In other words.. I drilled out my jet to a 150, which is far too big. If I had a manual valve on there, would it allow me to cut the fuel a bit? or would that just cause other problems? I have a couple smaller jets coming though...(thanks again)

Posts: 1893

Trying to adjust fuel delivery through your fuel valve is too imprecise. You will need to experiment with jets and spark plug readings to get the optimum air/fuel mix.

In my case, the stock restrictive fuel filter and 1/4" line required me to use an overly large jet to get enough fuel delivery. On top of that, flow varied between a full and half-full tank. Once flow was unrestricted, I was able to use a smaller jet that delivers consistent volume through out the capacity of the fuel tank. I do not blame the manufacturer since the stock configuration did not place as much demand on delivery and it was sufficient.

Posts: 705

Posts: 4286

I used a valve from a briggs and straton riding mower. I have sent the jets to you. so when you get them you can enlarge the fuel line at the same time

I used the same type og barb fitting that supersoxy used.

Posts: 1215

this sunlb came with 1/8 ID gas line with no inline fuel filter when i put a inline fuel filter on it with still stock main jet it would only stay half full that was after a hard run on black top.
i went up to a 1/4 ID gas line and gas filter stays full now even with my jetting that i'm running now.also i'm still running a vacumm petcock.
another thing the gas line that came with this buggy was cheap
turn hard and brittle after a short while.
pud

Posts: 238

There's a few cracks already showing in mine as well, but it will be better sheltered for the winter this time... lesson learned. So I'm getting some clear 'blue' gas line hose of both sizes (1/4 and 5/16) to test out when my jets arrive. Should work better, and look better. Seems odd they wouldn't put an inline filter on your sunlb, Pud.. little risky isn't it? I have some clear filters on order as well... stock filter is white plastic, can barely see the gas in it, nevermind any blockages. And since I ran my tank dry and plugged up the intank filter with crud, I'm sure the stock filter isn't in much better shape.

Posts: 1215