26th Nov 2011, 19:28

Hello. I own a 2008 Nighthawk. The size 40 slow jet is only listed as a part for the l986 CB450SC. Its part no. is: 99103-420-0400.

The 38 slow jet is listed: 99103-KR3-0380, but that is listed. Right now my bike bogs in the low end, so it definitely needs re-jetting on the slow jet. I just am not sure if it is a 38 or 40. If it needs one size up from stock, then it seems a 40 will be better with an opened up airbox. (I opened that up, and with the lean jetting, it spat like a mad toddler) Did you open up the exhaust also? Seems like good work. Thanks for a reply. Sincerely, Par3pio2@msn.com Paul Reichle lll.

13th Dec 2011, 21:33

Hello.

I did what another owner did first, and put in one size bigger jet. 38 and 115. I put two small No. 4 washers on the jet needle. After my ride tonight in cold weather, the Denso Iridium plugs still read lean. I purchased also a 40 and 120 like this post, but the 40 was a different part no. and it is longer than the two other OEM pilot jets. Does this matter that it sticks further down in the carb. bowl?

I am going to add one more washer to the jet needle first, because it seems okay in the idle and low range. This also is why I didn't put on the K&B air filter, and I am glad I didn't. This is the process of trial and error. I was hoping you may have a part no. Honda for the 40 idle jet.

Thanks. Par3pio2@msn.com