f375818 Report post Posted March 12, 2020 Starter motor turns but will not crank genset. House batteries new and fully charged. Removed starter for bench test. Again, starter motor turns, meter shows 12.4 vdc while starter is under test. Reinstalled starter in genset with the same results-start motor solenoid engages with starter spinning but still will not crank genset. Is it possible that the start motor reacts as indicated during bench test (no load) but does not have enough torque to turn the genset (max load)? Cannot find Onan start motor on inet but found a Cummings starter that looks the same with the same part #. Looks like it would work but hesitate to order because "electrical" parts are generally non returnable. Could it be that the start motor just needs new brushes? Any help appreciated!!! Share this post Link to post Share on other sites
wolfe10 Report post Posted March 12, 2020 Measure voltage at the generator starter when engaging the starter. If voltage drops below 12.0 VDC, may be a loose or dirty connection from battery to genset. Be sure to check the ground side as well. Share this post Link to post Share on other sites
f375818 Report post Posted March 12, 2020 waiting for helper to get back from hairdresser. More info: 7.5 KW quiet diesel HDKAJ Spec "J" 2005 model. Start motor sounds the same in the set as it does on the bench - in other words - "no load". Genset engine is not turning when starter is engaged. Sounds as if the start pinion gear is not engaging with the flywheel however the pinion gear was moving when bench tested leading to my suspicion that there is not enough torque to turn the engine. Ideas??? Share this post Link to post Share on other sites
frank.bergamo Report post Posted March 12, 2020 Bad bendix gear? Brush’s In starter wired wrong, turning starter backwards? Share this post Link to post Share on other sites
manholt Report post Posted March 12, 2020 Lose or dirty ground wire! Did you do as Brett said? Read his qualifications under signature! Share this post Link to post Share on other sites
hermanmullins Report post Posted March 12, 2020 Did you see the Bendix move when you bench tested the starter? It could be just stuck on the shaft and not being slung into the fly wheel when the starter is activated. Just a thought. Herman Share this post Link to post Share on other sites
wildebill308 Report post Posted March 13, 2020 9 hours ago, F375818 said: Cannot find Onan start motor on inet but found a Cummings starter that looks the same with the same part #. Looks like it would work but hesitate to order because "electrical" parts are generally non returnable. Welcome to the forum. Cummins is Onan. Bill Share this post Link to post Share on other sites
f375818 Report post Posted March 13, 2020 Thanks for replies. Good info from all. Won't have time to get back to genset problem until weekend. Will post results Saturday evening. Share this post Link to post Share on other sites
dbenoit Report post Posted March 13, 2020 It must be genny week! Share this post Link to post Share on other sites
manholt Report post Posted March 13, 2020 Bill is correct..Cummins/Onan is the same and most have Kabuto engine! DB. Welcome to our world! Everything comes in cluster! Share this post Link to post Share on other sites
dickandlois Report post Posted March 13, 2020 More info: 7.5 KW quiet diesel HDKAJ Spec "J" 2005 model. OEM Part number for starter is 191-2200 Replacement part is close to 300.00 with tax. They do not fail very often. When the helper returns to help read the starter voltage. That information would be helpful when posted. The attached PDF files are repair and parts lists Rich. 981-0200C Onan HDKAJ HDKAK (spec A-F) HDKAT (spec A-B) Genset Parts Catalog (07-2001).pdf Onan_6000_8000__Service_Manual-981-0522B.pdf Share this post Link to post Share on other sites
dickandlois Report post Posted March 13, 2020 2 hours ago, manholt said: Bill is correct..Cummins/Onan is the same and most have Kabuto engine! Carl, The Kabuto Engines are in the 10 and 12 KW generators. The QD, Onan Diesel engine is in the 6 to 8 KW generators. Rich. Share this post Link to post Share on other sites
wildebill308 Report post Posted March 13, 2020 48 minutes ago, DickandLois said: Carl, The Kabuto Engines are in the 10 and 12 KW generators. The QD, Onan Diesel engine is in the 6 to 8 KW generators. Rich. The 7.5 QD in my 2003 Bounder was a Kabuto. Bill Share this post Link to post Share on other sites
wolfe10 Report post Posted March 13, 2020 Guys, It is Kubota (with an a). https://www.kubotausa.com/about Share this post Link to post Share on other sites
wildebill308 Report post Posted March 13, 2020 22 minutes ago, wolfe10 said: It is Kubota (with an a). Rich said with an "O" and I just followed him. Bill Share this post Link to post Share on other sites
dbenoit Report post Posted March 13, 2020 Rich, Where did you get that parts list? I want to see if I can get one for my model. Nice breakdown. And the KaboatO........ David Share this post Link to post Share on other sites
dickandlois Report post Posted March 14, 2020 9 hours ago, DBenoit said: Rich, Where did you get that parts list? I want to see if I can get one for my model. Nice breakdown. And the KaboatO........ David Think I got lucky one day while looking for something else. Glad it looks like something you might like to have. Regarding the Kabota Engines. Think There might be one for the engine used on the 10 and 12 KW units on file? Will take a look between projects. Give me a day or 2. Rich. Share this post Link to post Share on other sites
manholt Report post Posted March 14, 2020 I've had 4, 8 & 10 KW, my current one is a 12.5 KW. Share this post Link to post Share on other sites
f375818 Report post Posted March 15, 2020 Finally got back to genset problem As Brett suggested , measured voltage @ starter when attempting to crank engine: results = 12.6 vdc constant indicating that starter in not engaging with flywheel. Pulled starter again & retested on bench. Starter motor spins up, pinion gear is working as the gear is slung forward with voltage applied. Voltage remains constant at 12.5vdc. I think that the motor is just not developing enough torque to turn the kubota. Although i don't like throwing parts at a problem without concrete diagnosis i ordered another starter from Cummings. Should be here sometime next week. Will post again when new starter is installed. Thks to all for your help. Share this post Link to post Share on other sites
wolfe10 Report post Posted March 15, 2020 Assume you have reached in and turned the motor over by hand to insure that it is not locked up (VERY rare). Also, with the starter out, check the teeth of flywheel. Share this post Link to post Share on other sites
dickandlois Report post Posted March 15, 2020 1 hour ago, wolfe10 said: Assume you have reached in and turned the motor over by hand to insure that it is not locked up (VERY rare). Also, with the starter out, check the teeth of flywheel. Ditto: Brett! Rich. Share this post Link to post Share on other sites
kaypsmith Report post Posted March 15, 2020 3 hours ago, wolfe10 said: Assume you have reached in and turned the motor over by hand to insure that it is not locked up (VERY rare). Also, with the starter out, check the teeth of flywheel. If you can at least turn the engine just a little, then try starting with the starter. It has been many years since I have seen a couple of teeth missing from the flywheel, but I have seen that to happen before. Share this post Link to post Share on other sites
jleamont Report post Posted March 15, 2020 Have you tried to supply a new ground to the starter while it’s installed or checked the current ground? A set of automotive jumper cables would suffice for a test. When you say won’t crank, does the engine spin when you attempt to start it, what sound does it make, just a THUD? where are you attempting to start it, at the generator or from inside the coach? Share this post Link to post Share on other sites
f375818 Report post Posted March 16, 2020 Nope, did not attempt to turn engine by hand. Considered doing so but genset is mounted in the front cab area surrounded by insulated panels with no slide for access. Turning the engine by hand would require complete removal of genset from the coach. Doable but a taxing endeavor for someone in their late 70's. Flywheel teeth that are observable with the starter out look good. Ground (and positive) cable connections from btry compartment are clean, bright and tight both at the rear of the genset and then again at the starter motor. Won't crank means starter motor is turning but the kubota engine is doing nothing. No movement, no thud, no normal or abnormal cranking noise, no nothing. Start attempts are made using the local control on the generator control panel as well as the remote switches in the coach. Same results using either switch. Considered trying to wedge a screwdriver or other prying device in the flywheel teeth and trying to move it slightly but the downside (if it can go wrong, it will) of that move could go very wrong very quickly. Also working space is very limited as i am working only within the small access space provided in the oil& fuel filter space. . Share this post Link to post Share on other sites
kaypsmith Report post Posted March 16, 2020 2 hours ago, F375818 said: Considered trying to wedge a screwdriver or other prying device in the flywheel teeth and trying to move it slightly but the downside (if it can go wrong, it will) of that move could go very wrong very quickly. Also working space is very limited as i am working only within the small access space provided in the oil& fuel filter space. It is great that you are cautious. Sure sounds more like the Bendix is just not kicking into the flywheel or teeth are missing from the flywheel. I looked up your starter and it looks as though the solenoid is made on top of the starter. Please let us know if this is true, or the Bendix is it only activated by spinning the starter. Share this post Link to post Share on other sites
