Stubby 19 #1 Posted August 24, 2021 My newly purchased 312-8 (2112K805) with Kolher magnum 12 M12S 471527 and am having a fuel pump issue. I cleared the lines and have a good flow coming out before the pump. Unfortunately it has the plastic pump on it. I am going to try and take it apart today and lube the pump with hopes it cures the issue. If not I am going to need a new one. I have one off of and K341 but unfortunately it has dust inside the pump when I took it apart. I noticed somewhere people put electronic pumps on theres. Not sure if I should do that or just but the plastic replacement. Share this post Link to post Share on other sites
peter lena 9,096 #2 Posted August 24, 2021 @Stubby , you can look at it a couple of ways , just pick up another plastic pump and swap it out , or if you are interested in the electric pump , this is the one I used , with very good results ,https://www.amazon.com/CarBole-Electric-Gasoline-Universal-Operating/dp/B01B7DCQA0, got the lowest pump rate , detailed new clear vinyl fuel rated line , 2 filters , 1 from tank and 1 to carb. if you are tight for time , the new plastic pump is quicker , but if you make a plan on the electric set up , its more reliable , been there , done that , pete 2 Share this post Link to post Share on other sites
peter lena 9,096 #3 Posted August 24, 2021 @Stubby that car-bole low pressure pump # is,425 , 2 psi to 3.5 psi , that's the one I used , that will not give you any over pressure issues on the horse CARB . ignition key start operation , pete 1 Share this post Link to post Share on other sites
Stubby 19 #4 Posted August 24, 2021 (edited) I worked on the existing one, took it apart and oiled the plungers I am guessing they are called. I reseated everything and ran it around the yard for a few. Seems to be doing fine at the moment. May need to sell this one and another one. Edited August 24, 2021 by Stubby 2 Share this post Link to post Share on other sites
Bill D 2,103 #5 Posted August 26, 2021 Consider something like this. I made this plate to allow me to use a vacuum impulse pump on these engines. Cheaper than OEM. The pump in the picture is a Kawasaki pump. 1 Share this post Link to post Share on other sites