Fuel Question

" Actually the fuel injection hose has caused some issues. i.e. carb debris. because the FI hose and less give you many times have to force it over barbed fittings that many use and this scrapes off the inner liner and causes small debris to float to the carbs and since the inner liner gets scraped at the fitting it's more susceptible to increased damage there. "

Am I the agent of thread drift?

I have discussed the topic of "barbed fittings" and hose damage many times.

I agree, the old style, multi ribbed, relatively sharp edged, often slightly tapered, usually brass barbed fittings are not only inefficient, they are likely to cause damage to the inside of the hose which may then result in debris entering the fuel system.

Point by point;

Old style - we now have much better designed push on fittings eg the Rotax supplied oil hose fittings - a smooth pipe with a collar/bulb at the open end. It would take great deal of effort to do damage to a correctly fitted hose, using this type of fitting. You will not find, a OM old multi barb style fitting on any ground vehicle that is under 20 years old.

Old style, multi ribbed, relatively sharp edged, often slightly tapered, usually brass barbed - Seemingly designed to damage the inner lining of the hose, the multi ribs seem like a sure thing to prevent leaks but in fact promote leakage. In a misguided effort to stop leakage the user will more often than not overtighten the hose clamp exacerbating the problem. Should the hose then be temporarily removed, the damaged inner surface sheds bits that enter the fuel system when refitted. The refitted hose is often so damaged, even more clamping pressure is applied to stop weeping, compounding the damage.

Slightly off Topic..or not..

  I would love Rotax to offer a Silicon hose option which should be good for 15 years...cost a bit more but the 5 year hassle...although sometimes needed is still a pain !

Unfortunately aircraft MFG's and owners still use lots of barbed fittings. If you have them just don't over clamp them. It doesn't take much pressure on the hose to hold it on a barbed fitting. This way you won't cut into the inner hose liner. 

Roger

"If you have them............."

Change them for the better style - you wont regret it - no leaks, no damage - no contamination.

Key to good hose fit ;

Correct ID hose for push on fitting - sounds like a no brainer but you would be surprised at how often the hose is too loose or too tight for the spigot.

In reusable hose clamps - Sleeved (used to be called FI clamps) hose clamp that minimise damage & give 360 degree pressure (variouse designs) OR latest spring type as used on all modern vehicles (need special pliers and must be accurately sized for application).

Clamp is more for security than leak prevention - gentle  tightening

On SLSA you can't change them and for some reason many use them on ELSA or home built. I guess they are just easier and cheaper to deal with?