dannyo 5 #1 Posted 14 hours ago (edited) Hi guys, I've got a 1965 875 WH (Kohler k181 8hp), and today I removed the fuel pump because I couldn't get it to crank and there was no plunger in the pump. I've been running the tractor for 5 years and this is the first time I've ever removed the fuel pump. My question is, is it possible for the engine to run without the plunger in place or should I take the engine apart and look for it? The diaphragm certainly needs to be replaced but wasn't sure if there is enough engine compression to still work the diaphram w/o the plunger... as a FYI, the last sentence is likely reflective of my ignorance on how engines work... Edited 13 hours ago by dannyo Share this post Link to post Share on other sites
8ntruck 8,768 #2 Posted 13 hours ago Any chance you have a vacuum operated fuel pump? These use the pressure fluctuations in the crankcase to move the diaphragm that pumps the fuel - they don't have a mechanical plunger. 1 Share this post Link to post Share on other sites
adsm08 4,360 #3 Posted 13 hours ago Vacuum pump, no plunger. 2 Share this post Link to post Share on other sites
dannyo 5 #4 Posted 13 hours ago that makes sense then, thank you both. Does anyone know of a source for purchasing reliable diaphragm material? Share this post Link to post Share on other sites
wallfish 19,743 #5 Posted 12 hours ago 1 hour ago, dannyo said: that makes sense then, thank you both. Does anyone know of a source for purchasing reliable diaphragm material? He's not as active on here as he used to be but try a PM to @buckrancher Brian. Quality Share this post Link to post Share on other sites
sqrlgtr 2,600 #6 Posted 7 hours ago My 701 had the vacuum style pump on it and I got the kit to rebuild from Then and Now auto, I believe they will just sell the diaphragm on its own, but you may have to call them to get one. 1 Share this post Link to post Share on other sites
953 nut 65,253 #7 Posted 2 hours ago 11 hours ago, dannyo said: today I removed the fuel pump because I couldn't get it to crank I presume you checked the output of the pump prior to removing it and found that it wasn't pumping. Also, you checked to see that you have spark. Here is a link to Then and Now. Be sure to tell them you have a vacuum pump. https://www.thenandnowautomotive.com/antique-auto-parts-store/Kohler-Fuel-Pump-Kits-c196218002 The kits offer two types of valves depending on your pump style. There are three vital moving parts in a fuel pump. The diaphragm, the inlet valve and the outlet valve. all of these components need to be working properly for the pump to work well. The Diaphragm is drawn downward when the engine's piston moves up the cylinder, this will develop a slight vacuum in the pump drawing fuel in if the inlet valve is operating properly. If the outlet valve is closing properly the fuel will be coming from the tank but if not it could be drawing fuel down from the outlet tube preventing it from reaching the carburetor. The Diaphragm is drawn upward when the engine's piston moves down the cylinder, this will develop a slight pressure in the pump pushing fuel up to the carburetor if the inlet valve is closing properly. If the outlet valve is opening properly the fuel will be coming from the tank to the carburetor, if not there could be no flow. 3 Share this post Link to post Share on other sites
c-series don 11,827 #8 Posted 1 hour ago Then and Now is business that you call and actually talk to a person, a nice person. Someone that is willing to help you. I’ve dealt with them a few times over the years buying fuel pump rebuild kits. I would highly recommend them! 2 Share this post Link to post Share on other sites
