Blue spring fuel pressure mod

[dirtbikr]

is there any risk in doing the blue spring mod without a fuel pressure gauge for a while until I can afford a gauge setup?

[howell_jd]

Simplistically the answer is "yes" however the risk is acceptable in most cases. Usually the stock spring does not provide sufficient force on the plunger in the secondary fuel bowl resulting in too-low fuel pressure under high-demand situations. This low-pressure situation produces damaging effects on injectors opened and closed by high-pressure oil. The updated blue spring is slightly longer to provide additional force under compression resulting in higher fuel pressure at the secondary fuel bowl. Of course if the fuel pump is not producing sufficient fuel pressure to begin with then the additional force of the updated blue spring won't add pressure and the same effect of a weak spring follows. The blue spring is not a fix-and-forget cure-all but is likely preferrable to retaining a known shortfall.

Go ahead, give into the pressure.

Jonathan

[Polkville]

When I ordered the blue spring, I decided I needed to check fuel pressure first. (cant justify spending nearly $300 on an EAS fuel press set up right now.)I did some research and discovered harbor Frieght sells an oil pressure test kit with a 0-100 psi gauge, a 66" hose and the necessary adapter to attach it to the fuel bowl. All for $25.00. I hooked it up and zip tied the gauge to my mirror and drove around awhile. Discovered my fuel pressure is good for now. Never dropped below 60 psi. Yes I know, it's supposed to be an oil pressure gauge, but it worked good for me.