Carb Float Repairs
in General Tech Discussion
10 years ago
The Rotax notice about carb floats absorbing fuel can be fixed by lightly coating the floats with a novolac (Rhino 9700 epoxy/phenolic) which is impervious to fuels and ethanol. This is the material used in integral fiberglass fuel tanks to keep the glass from being effected by ethanol mogas. It's also the same coating used to protect concrete floors from chemical attack and provides that hard, shiny surface. The novolac has low viscosity and can be brushed on the floats with a fine artist's paint brush.
We weighed the floats before coating application at 85 grains (5.5 gms) per pair and 95 (6.2 gms) grains after coating, within the Rotax limits of 7 gms per pair. We are submerging the floats in mogas with 10% ethanol and will reweigh them in a week to look for weight gain. If none, then the coating should extend the life of the old floats by blocking fuel absorbtion.
This is not an approved Rotax fix but I believe it will work well. Will report in a week on results.
Bob H
We weighed the floats before coating application at 85 grains (5.5 gms) per pair and 95 (6.2 gms) grains after coating, within the Rotax limits of 7 gms per pair. We are submerging the floats in mogas with 10% ethanol and will reweigh them in a week to look for weight gain. If none, then the coating should extend the life of the old floats by blocking fuel absorbtion.
This is not an approved Rotax fix but I believe it will work well. Will report in a week on results.
Bob H
