New Carburetor for Honda CT90 Trail 90 K1 K2 K3 K4 Carb 1970-1979

Bought this for a '71 Honda CT90 and only had to modify the drain tube. Everything else fit perfectly and I was already prepared for the modification, thanks to other reviews and videos. It only needed a bit of fine tuning and the bike was running great!

REF: '71CT-90: Like other reviewers, the placement of the bowl drain nipple is problematic. And no mounting stud were provided. Thus, only 4 stars. I followed the advice of the reviewer who plugged the existing port and drilled a new port in the proper place. However, I should have first removed the bowl. I was unable to find a way to clamp the entire carb to my drill press platform, so I used a hand drill. The bit "wandered" requiring epoxy to seal the nipple in the slightly enlarged hole. I had to remove the bowl, anyway, to make sure no metal shavings were left in the bowl (there were) or the passageway, CAUTION: Make sure you remove the bowl drain screw completely before drilling. Instead of taping the original hole, I found a piece of steel rod that interference fit. Tested everything with water to make sure there were no leaks and the drain function worked properly before replacing the bowl. Luckily I had M6x100 bolts available to cut to size and Loctite into place as mounting studs. Once installed, the bike started on the first kick and needed only a minor adjustment of the idle speed after warming up. The hesitation I'd been experiencing with the 50-year-old OE carb, despite repeated removal and cleaning, was cured. Bike runs great. If you're up for the modifications I've described, I'd heartily recommend this as a great value.

All replacement CT90 carbs are not created equal. I inherited a 75 CT90 with another brand of replacement carb and I could never get it to run correctly. I messed with needle position, float level, and the idle jetting but could never eliminate a stumble just coming off of idle. This carb worked perfectly right out of the box.

Installed the new carb on my 75 ct90. First the drain nipple is on the bottom so you have to trim that for it to even fit (don't understand why they didn't put it on the side like the stock one). The bike would start after a few kicks before the new carb but now I've only been able to start it one time.

Works like a charm. You do have to trim the drain nipple (as pictured), but once you do that it fits and works well. I love that it comes with a reserve on the petcock too!

The reviews that mention the gas drain line pointing straight down are, unfortunately, true. In every other way this carburetor is a direct replacement for my 1970 Honda Trail 90. I don’t know why they chose to put the drain port there, but it was frustrating to get it all the way installed, then realize it won’t work with the drain hose. I did find a work-around. After disassembly, I pulled the brass hose barb out and used a 5/32” drill bit to drill out the correct drain location. The carb body is aluminum, so you don’t need steel drill bits. I was able to gently tap the brass hose barb back into the new location. I used a 10/24 tap to cut screw threads into the old location. I used an aluminum 10/24 x1/4” screw with thread locker and a fiber gasket to seal the old hole.

My CT90 fired up on the 3rd kick! Such a great buy. Didn't have to adjust any of the screws. As others have mentioned, the only downside is that you need to snip off the excess fuel nipple because it's too long. Very easy to do though because the metal is soft. Thank you!!

Made my customer smile real big. He brought me a Honda CT90 to repair and so I did. This made it a breeze for me the only part is that the overflow part is too long but fortunately it snapped off so that actually kinda helped. The other reviews are not wrong about that so on durability ill give it a 5/10. It is made out of pot metal so... but out of the box it was adjusted perfect for the bike. I did not even tweak the screws. That is amazing! I think the carburetor will hold up for a very long time. To me and the customer the overflow thing is no big deal. When we want to frain the gas we'll have to let it drizzle all over the engine block.

Works great on a ct90.

Good quality. I knew in advance I would have to cut the drain shorter so no problem there. Instructions would have been a bonus but hooked up, adjusted and working well.

Tried on 71 ct 90. No matter how you adjusted the throttle it would rev moving the handle bars to the right. Put stock cap on and that fixed it. Then the needle valve jammed when the float would drop causing fuel to leak out of the overflow constantly. Then when I removed the float to try and correct the issue one side of the float had a hole in it causing it fill with fuel. Junk. Returned.