markseven 93 #1 Posted 7 hours ago Wondering if anyone can give me a tip On installing a new diaphragm in the old Kohler 301 Original pump. Want to try and do it right so it doesn't fill The crankcase with a gallon of gasoline again. Share this post Link to post Share on other sites
Retired Wrencher 6,465 #2 Posted 5 hours ago (edited) Quote Then and now have the best ones I have seen. Sorry i do not now the address or full site name. Quote Edited 5 hours ago by Retired Wrencher Share this post Link to post Share on other sites
953 nut 64,187 #3 Posted 4 hours ago prior to tightening the screws on the pump body clamp it in a vise and push the plunger rod all the way. This will properly position the diaphragm. 2 Share this post Link to post Share on other sites
ri702bill 11,289 #4 Posted 3 hours ago 1 hour ago, 953 nut said: prior to tightening the screws on the pump body clamp it in a vise and push the plunger rod all the way. This will properly position the diaphragm. Indeed. That pre-stresses the diaphragm to allow movement. Avoid this step & the diaphragm will tear.... 1 Share this post Link to post Share on other sites
pfrederi 19,936 #5 Posted 3 hours ago https://www.thenandnowautomotive.com/antique-auto-parts-store/Kohler-Fuel-Pump-Kits-c196218002 Sorry but for less money you can buy a Carbole electric pump which many people here have used and never have to worry about gas in t crankcase again. If you want to spend a bit more get a made in USA Facet posiflo. 2 1 Share this post Link to post Share on other sites
sqrlgtr 2,184 #6 Posted 2 hours ago All of the above. I found that the then and now diaphragms are on the thin side, but the only place I have found where you get the internal valves with kit. I started making an extra gasket to go in between pump body and diaphragm to keep them from leaking, even after stoning pump body halves to make flat, they were hard to get to seal up for me. Be aware there were a few different styles of pumps used so make sure you order the right one if you order a whole kit. Just turn diaphragm 90 degrees to remove. I had ordered a few diaphragms from isave tractors before he went out of business, and they were made with a heavier material and sealed up better. I have used the later plastic pumps also and have had good luck with them myself, but others have not. Share this post Link to post Share on other sites
peter lena 9,775 #7 Posted 2 hours ago @markseven BEEN USING CARBOLE 2-3,5 PSI ELECTRIC PUMPS FOR YEARS added ADDED A led dash light to verify its function , my 3 horses have the same , problem eliminating set up ? fuel check valve , to hold and verify fuel to carb , filter and clear fuel rated hose to carb , showing you its there , also have filter just after leaving tank , went after every issue spot and eliminated it . try / test / verify . regularly make up something that lets me make a change , ( you already know what fails ) often staring right at you , also function detail in the throttle linkage ? is every movement spot smooth , easy moving / sliding ? like throttle / choke cable lubrication slide ? this is baseline stuff for me , that I evolved to , nothing sarcastic implied , just what I regularly do , pete Share this post Link to post Share on other sites
WHX?? 55,107 #8 Posted 2 hours ago Glass the halves and don't overtighten the screws is the best advice I can give. Share this post Link to post Share on other sites