Can't get forklift running properly. Have to keep the primer button on the converter pushed in with a little stick to keep it pushed in in order to keep it running. I've replaced the converter with a new Impco Model J, but no difference. Then I took the mixer apart, and cleaned it out, it was very dirty with oil + dust buildup (Does the diaphragm have oil below it, so when you push on the diaphragm you get oil coming out of the 4 air passages?). Still no difference. Then took the lockoff valve off, cleaned out the filter with compressed air (had some small metal filings in there too), and put it all together, but still no change. The forklift is really old and doesn't warrant a mortgage. When I pushed in the diaphragm on the lockoff valve, I can get the machine to run , but I have to keep the revs up because when I let it go to idle it just dies. And then to start it up, I have to push in the converter primer button etc. and do it all over again. Anyone able to advise me on my next steps to try?