Searcher60 209 #1 Posted September 2, 2017 On the late model WH 520 H with 20 HP Onan, some have the 146-0698 Nikki emissions carb. That carb contains an accelerator pump. The manual calls for carb replacement if there is any problem. However, some say there are kits available for this carb. It is one expensive carb. It looks to me that if the accerator pump diaphragm has a leak, the engine will run rich when running, and when not running, the fuel in the carb bowl will drain into the intake. Anybody else tackle these issues? I think there is a kit to rebuild and a kit to repair the accerator pump. Anybody know the correct main jet size for the 146-0698? This really sucks. These things are money suckers. It never seems to end. Share this post Link to post Share on other sites
WVHillbilly520H 10,376 #2 Posted September 2, 2017 I have "rebuilt" my Nikki emissions carb on my anniversary using the Onan service parts they can be obtained from "Onanparts.com" or any certified CumminsOnan dealer, I don't know the size of the main jets other than there's "low" and "high" elevation jet kits, and others have retrofitted the older carbs vs messing with these, @lynnmor I believe has done this and still has the emissions carb on a shelf, Jeff. 2 Share this post Link to post Share on other sites
Searcher60 209 #3 Posted September 2, 2017 33 minutes ago, WVHillbilly520H said: I have "rebuilt" my Nikki emissions carb on my anniversary using the Onan service parts they can be obtained from "Onanparts.com" or any certified CumminsOnan dealer, I don't know the size of the main jets other than there's "low" and "high" elevation jet kits, and others have retrofitted the older carbs vs messing with these, @lynnmor I believe has done this and still has the emissions carb on a shelf, Jeff. Thanks for the reply. In the accelerator pump kit picture. The gold piece on at the top of the 3 screws, what is it and where does it go? Also, the little O ring next to the little spring, where does it go? Thanks again! Share this post Link to post Share on other sites
WVHillbilly520H 10,376 #4 Posted September 2, 2017 18 minutes ago, Searcher60 said: Thanks for the reply. In the accelerator pump kit picture. The gold piece on at the top of the 3 screws, what is it and where does it go? Also, the little O ring next to the little spring, where does it go? Thanks again! Sorry it's been 5+ years since I done this but I'm pretty sure there's an instructions sheet that comes with the kit if I can find it I'll put a pic of it up. Share this post Link to post Share on other sites
boomers_influence 106 #5 Posted September 2, 2017 seacher60 and club there are NO instructions for the emissions carbs.( 146- 0697,0698,0699 and 0700 ) they DO NOT want us to work on them. ( i do stock the accel pump kit ) the 146-0698 has a # 238 venturi and a # 122 main jet. the prior carb for the P 220 is the 146-0414 and the 146-0479. both of the above have a # 238 venturi and a # 134 main jet. for TEST PURPOSES i could sell you a NON emissions carb. boomers_influence@yahoo.com thank you. boomer ( the used onan engine parts guy, also NOS and new ) Share this post Link to post Share on other sites
Searcher60 209 #6 Posted September 2, 2017 7 minutes ago, boomers_influence said: seacher60 and club there are NO instructions for the emissions carbs.( 146- 0697,0698,0699 and 0700 ) they DO NOT want us to work on them. ( i do stock the accel pump kit ) the 146-0698 has a # 238 venturi and a # 122 main jet. the prior carb for the P 220 is the 146-0414 and the 146-0479. both of the above have a # 238 venturi and a # 134 main jet. for TEST PURPOSES i could sell you a NON emissions carb. boomers_influence@yahoo.com thank you. boomer ( the used onan engine parts guy, also NOS and new ) Are you a vendor? Got a website? Thanks Share this post Link to post Share on other sites
