Jet compatibility

R

Rutabaga

Member
My ‘76 CT 90 has( as far as I can tell) after market two screw carburetor that is fairly new, does a good job. It has a Keihin 35 pilot and a Keihin 58 main with K65/168 needle with the clip one above middle. No problems or complaints but I would like to try this
I looked at a few of the usual sources and did not find this size in their offerings, most of the kits ranges were far too broad for what I seek. Local Honda dealer graciously spent some time trying to track one down and did find it from a catalog. Both sources seem to show a Keihin product that I suspect will fit the needed specs. I live at 5200’ and all of my riding is above that and up to about 7700’ with 9000’ available soon. Any concerns or experiences with replacement or fitment of one Keihin jet size for another. Also is there any way to identify which carb I have when I can not find any brand or logos of any type on the carb or does it not matter when swapping the same brand main jet for another size of the same brand?
Current jets and needle. IMG_4726.jpegIMG_4721.jpegIMG_4619.jpeg
 
No, if it looks different, it is different.. Any non oem jet I have used in a oem carb ''matches'' looks in pics/measurement wise. If you want to go a little leaner/richer on the pilot, try a slight mixture screw adjustment, if you can't find the pilot jet. If it runs good now like you say, if it ain't broke don't fix it.
 
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OLD CT said:
No, if it looks different, it is different.. Any non oem jet I have used in an oem carb ''matches'' looks in pics/measurement wise. If you want to go a little leaner/richer on the pilot, try a slight mixture screw adjustment, if you can't find the pilot jet. If it runs good now like you say, if it ain't broke don't fix it.
Click to expand...
Well, another “RTFQ” or “RTFP” (question or post) moment for me. I did order the above 62 main jet and waited patiently until it arrived last night.
IMG_4750.jpeg
Compared it to the 58 jet that I had removed and it looked similar in some regards; it was brass looking, had a number stamped on the top, and had threads to screw it into the main jet orifice.
IMG_4726.jpeg
Then, as Old CT so succinctly put it, “if it looks different, it is different” and my 58 jet has the collar and screw slot on the top. The one I ordered has the collar on the bottom and the screw slot on the threaded top. Yep, it’s different alright. The listing showed what carb it will fit but I can’t not find any markings , numbers, or any such identification on the carb body I have so as to help me with knowing its manufacturer or type.
IMG_4720.jpeg IMG_4752.jpeg
This is the innards and outside. Not real sure if there is an advantage to having that information when ordering jets , etc, but it may help me in reducing my mistakes like this one. On a happier note I am thrilled with the fuel line length I installed as it makes removing the carb( and fuel tank) so much easier and with less spillage.
Totally my fault in getting the wrong part, I saw what I wanted to see and not what was presented in the ad.
 
I bet you can find a carb with the altitude adjust if you ask around and keep an eye out on ebay. What does on top of the flange next to the plastic intake spacer say, shifter side? Ahh aftermarket, just blew up the pic. Send Niche ''a pic'' of the pilot or main in the email. Go to ''jets r us'' and check pics as well. I had a knockoff pz19mm they had jets for. Lemme look in my pile.
 
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It looks like a Mikuni small round main jet. Type in the Ebay search, Mikuni and Keihin small round main jet #65 N102/221 The symbol next the original jet# stands for Mikuni or Keihn. Kinda leaning toward Keihin like Dirtbikr said. Here is a Keihin, small round main but double the jet # in size.
IMG_2760.jpg
 
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Thanks for all the shopping tips, locations, etc. I went about the replacement tasks with fervor but not enough facts. My neighbor has a micrometer and the skill to use it so that I may follow the Jets R Us guidelines and get the right size.
I am familiar with the original carb and the altitude compensator knob; nice touch but what’s the fun in pulling a knob when I can rejet and move needle clips. I have absolutely no beef whatsoever with the current carb, I have it nailed on idle mixture and speed settings, it is simple to work on and to tinker with and the performance as it stands is impeccable in my opinion. I am a tinkerer at heart and I enjoy it equally with the result of being able to ride after the effort. Yesterday I slapped it all back together in about thirty minutes and then went back out on an unknown Forest Service Road for some bone jarring scenic desolation. So many trails, so little time.
 
I contacted riftwild.com and got a prompt reply to my enquiry. Alexia located the needed jet and sent a link so I ordered one.

riftwild.com

Carburetor 99114-077-0620 Main Jet Number 62 Compatible with Honda

Contains one (1) Genuine Honda Carburetor 99114-077-0620 Main Jet Number 62 They are only available through Honda New Old Stock Part Original Fit - Designed and manufactured to work perfectly with your vehicle Need Help? - Message us before purchase if you are unsure about the item fitting your...
riftwild.com

The chase is on!
 
You are correct, it does not. However, at this point I am going to let the order go through and I will see if it fits. Not too worried about the appearance of the shoulder width as long as the threads are compatible and the jet size is correct. This process is like rebuilding an ancient pyramid with modern paving stones using Braille for sizing information. Strangely I still like the process.
 
Unless I missed something in this thread, isn't the main jet you posted in the very first post the one you removed from the carb you are using? Looking very much like the one I posted in post #9?
 
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