Crmaverick 91 #1 Posted June 22, 2022 I pulled off my fuel pump and noticed there’s no arm coming off the back. The motor is a 1964 k181 off an 854. All the pumps I’ve seen have an arm do they break off and end up in the crank case? Or did they pumps without the arm that are vacuum? Share this post Link to post Share on other sites
ebinmaine 67,487 #2 Posted June 22, 2022 It's not broken. You're good. Likely never had an arm at all. Lots of those small engine fuel pumps are vacuum signal operated. They're pushed and pulled by the piston going up and down in the crankcase. Share this post Link to post Share on other sites
ri702bill 8,319 #3 Posted June 22, 2022 That would be a vaccum pump. My 854 that I bought used has a lever style pump with the priming lever... Bill 2 Share this post Link to post Share on other sites
ri702bill 8,319 #4 Posted June 22, 2022 (edited) On 6/22/2022 at 10:00 AM, ebinmaine said: They're pushed and pulled by the piston going up and down in the crankcase. And they both use the same type of diaphragm material, though not the same construction. What is the same is that when (not if) it ruptures, raw gasoline will dilute the oil and can lead to "engine failure". This is why it is oh so important to check the oil before use... Bill Edited June 23, 2022 by ri702bill 6 Share this post Link to post Share on other sites
