How tight to clamp fuel injection hoses

Question

I have a motorbike (Ducati 696, 2012) with high pressure fuel hoses feeding fuel injectors. The hose is a gates 4219g as built from the factory. It sprung a leak which I can't trace from the hose or from the injector. I broke the hose clamps which were single use (ear style clamps) and I was hoping to replace a section of hose and reclamp the lines.

I found a product called dorman fuel injection hose clamps which have a worm drive tensioning. How much should I tighten these to gain good seal but not to break the belt? Online sources indicate you "tighten until you meet resistance and then back off slightly". Does a high pressure line have higher resistance than a normal hose then?

Answer 1

The standard "high pressure" of your Ducati is 41 to 46 psi (~3.2 bar). By today's standards, that's nothing compared to a direct injected engine. Just about any hose clamp can do the job and keep it from leaking. "How tight" is very subjective, though. I take it you're replacing the typical stepless or crimped style hose clamps.If you can find those, they would be your best bet for replacement. With those, you just crimp them and they hold in place. If you're using a jubilee clamp (worm style), tighten them the old German way "guttentite", or tight enough so you feel good resistance when turning, but not so tight you start seeing the clamp cut into the rubber. There should be a barb or bulge at the end of the tube you're putting your hose on. If not, this is a good way for it to work itself off regardless of how tight you make it. There had to be something there the clamp won't slip over.