YT175 choke settings/adjustment

[ddiggerr]

Finally took the tri moto out for a run, however, once in first gear it bogs down under load.

I have sprayed everywhere around engine that I could find where it might be sucking air, but no change. Thought maybe I had too much oil mixed into gas, but no. I did have choke cable apart to oil it.

Now its not opening as much as it used to be. I have checked online and through the manual online, but there is nothing mentioning the proper settings for the choke.

I have fumbled with it and fail continuously

Anyone have a suggestion?

[Racer-X]

Did you happen to change your spark plug during your tune up? I had the same trike with the same symptom. I took apart the carb and cleaned it along with the head and the whole 9 in the spring. It idled fine and seemed good as long as I was under 5-10% throttle then it bogged out big time . Not even rideable. After checking things over again and again and scratching my head for a while, I picked up the dirty old spark plug out of the dirt and put it back in the trike and it ran fine again. It didn't like that new spark plug I put in it for some reason???

[ddiggerr]

I do believe I put in a new plug. Will have another look. Might also have another look at the float. Just a real bear getting that air box assembly on and off. What a royal pain

[dgm635csi]

Adjusting the choke is easy to do, but a little challenging to explain. The choke assembly is comprised of 6 main parts. The first three are the choke cable, the choke plunger, and the plunger return spring that rests behind the plunger. The other 3 parts are the brass choke body that threads into the carb, then there's the choke adjustment collar that threads into the brass choke body, and the locknut on the adjustment collar. The choke plunger gets pulled into the brass choke body against the return spring, and out of the carb partially when the choke is engaged. There is a o-ring on the choke plunger that must be in good condition, or extra air may be drawn in through the choke body causing a leaner condition. I would advise that you check the condition of the plunger o-ring by unthreading the choke body from the carb using a 12mm open wrench. When you unthread the choke body fully from the carb, the entire assembly comes out from the carb as a unit allowing inspection of the o-ring on the plunger as well as the choke orifice on the carb. My plunger o-ring was OK, but I did lubricate it with the silicone vacuum grease to ensure a good seal inside the choke orifice before I reinstalled the choke body and plunger back into he carb.

As far as adjustment goes, the design would indicate that there is some adjustment, but I found that on my yt175, the choke is properly adjusted when the 10mm locknut is threaded as far out (away from the carb) on the adjustment collar as physically possible, and the adjustment collar and locknut are then threaded into the brass choke body as far as they will go until the locknut on the collar rests against the brass choke body. At this point, the plunger return spring is compressed slightly between the adjustment collar, and choke plunger. This keeps the plunger fully seated inside the choke orifice of the carb when the choke is not engaged.

When the choke knob near the handlebars is pushed down (choke off), you should be able to pull the choke cable (by its sheath) outwards from the adjustment collar on the choke housing about 1/2" before it stops. When you do this, you are pulling choke plunger into the brass choke body, and fully compressing the plunger return spring behind the plunger inside the choke body. When you release the cable, the plunger return spring should seat the cable back into the adjustment collar. Now, try the same thing with the choke knob near the handlebars pulled up (choke on). The choke cable should not want to move outwards from the adjustment collar since the choke plunger is now being pulled into the choke housing by the choke cable.

I know its a bit convoluted, but I hope this helps with any questions about the choke.

Duncan