We have a 2010 dvx 90 today it started fine and begins to accelerate but then bogs out and dies. I removed cover on auto choke and rotated back and forth now it run perfect. I assume it was either stuck on or off. Can this be removed and cleaned, is it a common issue with these quads?

 

Electric chokes sucked no matter what machine they were on. Most small youth machines used the same type carb. You can get a manual choke model as a replacement or simply disconnect the electric choke,block off the air tube with your thumb or hand on cold starting. Once warm they would crank up easy.Manual choke changeover kits are out there,but may not be worth the effort or cost and may or may not fit some models.https://www.ebay.com/itm/Manual-Chok...5ZeAjm&vxp=mtr
https://www.ebay.com/itm/NEW-OEM-Car....c100012.m1985

 

How do they work exactly. Is it a electric so kobold plunger type thing? What is the common problem with them, do they simply get dirty and stick?

 

You can try to clean one if you're careful. On cold starts the plunger is supposed to rise allowing extra fuel into the engine. As it warms up the plunger closes and shuts off the extra fuel. Or at least it's supposed to..On Polaris youth machines we just blocked off the air inlet tube and they'd fire right up on cold starts. That procedure came from Polaris because they knew that the electric chokes weren't reliable. Soon after manual choke conversion kits were offered.

 

just out of curiosity how does determine when to drop the plunger back down? Is there an electronic temp sensor somewhere

 

Built into the choke assembly.

 

It is both counter intuitive and simple. The needle valve is connected to a wax thermostat and, when cold, the valve is open (up). The electrical wires go to a heater element touching the wax thermostat. Other end of wires are directly connected to the alternator wires. So, cold engine, needle valve up and open, after the engine starts, power from the alternator makes the heating element warm up the thermostat, which drops the valve, closing it. It takes a while for the element to cool down after stopping the engine, so re-starting a warm engine, choke plunger still down.

A further refinement on Honda's system is a small chamber full of fuel, connected to the float chamber by a very small hole, the needle valve takes it's fuel from this chamber. So first draw gets a lot of fuel, but when all fuel in the chamber has gone (usually the bike has started by now,) fuel has to be drawn from the float chamber through the small hole, giving a part choke effect until the thermostat closes it off altogether.

 

Thanks for the explanations guys. So in my case do you think this could be my problem . Bike starts idles fine runs fine for for minutes then wants to stall when throttle is applied. It will still idle perfect. Is plunger not fully closing after it warms up causing it to run to rich and stall. If you let go of throttle when it begins to stall it will go back to a perfect idle.

 

I didn't read where you cleaned the carb. Sounds like a plugged jet.

 

Oh...hopefully that simple. I will clean it and test operation of enricher and post results. Thanks again guys