I had a hard warm start problem until I changed the fuel filter and the fuel regulator. I don't know which actually had the problem. The filter did seem to have some pressure on the back side which may be normal, I don't know. If you do the regulator, you may want to purchase the high quality small fuel line hose under the regulator, because it was a little hard to remove and I broke it unexpectedly. It was brittle though and in need of replacement. Hope this helps.