Workin_Horses 14 #1 Posted July 8, 2011 I have a 520H that when I turn the key sometimes the starter just spins but doesn't engage the flywheel to start the engine. This is erractic as sometimes is starts on the first try and then sometimes I have to turn the key 2 or 3 times before it starts. It has the 2 cylinder 20 horse onan engine. Any ideas what might be causing this? Share this post Link to post Share on other sites
CRE1992 135 #2 Posted July 8, 2011 The bendix is most likely sticking, could be gummed up or the spring is worn out. Share this post Link to post Share on other sites
can whlvr 991 #3 Posted July 9, 2011 i have not ever worked on an onan starter but if anything like a kohler starter you need to remove it ,tear it apart carefully,as not to loose anything,take note of how it came apart,clean and inspect,and the gear on the end needs to be lubed,you can get the proper oil from an auto store then put together,thats with a kohler starter,maybe an onan is similar,this way you will see how the inside is looking,the gear,the brushes,armature,cap,springs,etc, Share this post Link to post Share on other sites
smoreau 658 #4 Posted July 9, 2011 i have not ever worked on an onan starter but if anything like a kohler starter you need to remove it ,tear it apart carefully,as not to loose anything,take note of how it came apart,clean and inspect,and the gear on the end needs to be lubed,you can get the proper oil from an auto store then put together,thats with a kohler starter,maybe an onan is similar,this way you will see how the inside is looking,the gear,the brushes,armature,cap,springs,etc, Sounds like the starter motor it self is fine as it spins every time you hit the key. sounds like the bendix ( gear the engages the flywheel ) is sticking. Remove the starter, use a screw driver and pry the gear toward the end of the starter. spray some wd-40, on the screw type bendix so it moves freely back and forth. that should take care of your problem. you do not have to take the starter apart. had to do this to several tractors that have sat for several years. Share this post Link to post Share on other sites
can whlvr 991 #5 Posted July 9, 2011 i only recommend that you take the starter apart if you have to take it off the motor then its not alot more work to inspect the inners to see it needs brushes or any of the magnets on the out side have dropped chunks,but thats just my opinion Share this post Link to post Share on other sites
shorts 182 #6 Posted July 10, 2011 Remove the starter and free up and lube the bendix drive with something like blasters or wd40 , as far as disassembling the starter go with "If it ain't broke don't fix it", the ceramic magnets and brushes can be relatively fragile and expensive if you're not familiar with electric motors. Share this post Link to post Share on other sites
8993-520 0 #7 Posted July 10, 2011 Not to argue with these guys but I think if you find you a good starter shop and let them rebuild for you you will be better off. What they are saying works but in my case only for a short while. So when I got tired of needing my mower and it wouldnt start I started looking for a replacement. You know what a toro shop wants for one these starters dont you? So that is when I looked for a local shop and took it to them. Replaced my solenoid and rebuild my bendix for 53.00 dollars 3 tears ago with no problems. So that is why I gave my 2 cents worth. Hope it helps a little. Share this post Link to post Share on other sites
can whlvr 991 #8 Posted July 10, 2011 i agree that it can be a temporary fix, but it has worked in my 414-8(#1)and 2 years still going strong,but also i had to purchase a new one this week for 414#2 it was 135 out the door no shipping and from a reputable starter shop Share this post Link to post Share on other sites
SAM58 30 #9 Posted July 26, 2011 Use something that will lubricate better than WD40 or Blaster, they have drying agents in them that leave a white chalky looking stuff. Small squarts of Lithium Grease, or if you take it off. I think Moly grease would last longer.... Another thought, how good is your battery? it takes a strong one to crank the 20 HP Onan. 300 - 350 CCA I tried a regular battery in mine, 180 CCA and it did what you discribed in your post. Bought a new one with 350 CCA and it started every time. Share this post Link to post Share on other sites