Conover Woodcraft Specialties Dust collector has weak suction

[Waltkurtz]

I bought an older dust collector. It is a Conover Woodcraft Specialties Model SF-209H 2 HP 12" Impeller – 8 Blade unit. There are 5? canvas/cloth tube-shaped bags on top, and a single large bag on the bottom. I don't think the suction is very strong. I just ordered the 12" Rikon impeller that people speak highly of. So same size, but different design, so I hope it helps.
For my next modification, should I consider different bags? I wonder if the airflow would be improved by replacing the cloth with something more modern. The unit is in its own enclosure tacked on to the outside of the shop area so as to keep the dust from the shop.

Anybody ever heard of these units?

Thanks

[retired2]

I'm not sure how you are measuring suction, but you can't judge the performance of your blower by subjective assessments.  You need to use an instrument to measure either the static pressure or the air flow. 

One thing I would do is quickly test whether or not cake in the filter bags has become so heavy that it is crippling performance.  Simply remove the five filter bags and run the unit without them to see if the suction improves.  If you have never cleaned any of the filter bags remove them, turn them inside out and vacuum them thoroughly with a shop vac, then reinstall them.

If you can adapt a pleated cartridge filter, such as the ones sold by Wynn, to your unit, that is a much better choice than canvas bags.