Hi Folk, I'm new here and could really use your help. I am a decent mechanic on the older bikes but this little 2004 roketa is giving me fits.
When I got it it would start but not stay running. would stall after only a few seconds. I first cleaned the carb, checked all the vacuum lines etc. new plug, the usual routine, and had no luck. while trying to reclean the carb I ruined the float gasket and after looking into it I just bought a brand new carby for it. I installed that with a new intake boot and it definitely starts easier and runs better and longer but still only about 30 seconds at a time. I have eliminated fuel supply as an issue it is getting fuel. It seems like the electric choke is messed up but. its brand new! This seems unlikely unless it is something in the wiring on my scoot. How would I check this? any other thoughts? the scoot only has 800 miles and doesn't "look" to have been abused. I don't think its a compression issue but I haven't check that yet. It does run strong when it fires.
You could start by checking if the choke is getting power. Start the bike up and look for about 12 to 13 volts AC at the wires leading to the choke. While you're at it examine the female electrical contacts inside the plastic connector. Many times they are permanently spread open and make poor contact with the male contacts because the Chinese terminals are made from fully soft copper instead of partially hard brass or beryllium copper that they should be made from. If they appear to be over spread they can be release from the plastic connector, reformed, and reinserted. You can test the choke out of the carb but more comprehensive test is to check it while installed on the carb. You can do this either with the carb on the bike or removed. You need to access the inlet face of the carb by removing the air cleaner hose. On this face you will find a small hole on the periphery of the inlet that leads to the choke. It's easy to identify which hole because you can see the outline of the communication passage leading to the choke plunger. Take a small hose and hold it over the hole and blow into the hose. Provided the bike has been off for 15 minutes or longer then air should flow freely into the hole. Energize the choke by disconnecting the choke electrical plug and applying 12 volts (AC or DC) to the choke terminals. You can also try doing this by just running the bike but it may not run well with the air cleaner removed. Within 5 minutes of the choke being energized you should not be able to blow air thru the hole. If everything checks out then I'd check your valve tappet clearances.
They call it an auto-choke, but it's really a misnomer. The carb has an enricher circuit, which mimics the function of a choke by feeding the carb more fuel. The "auto-choke" is basically an electrically powered heat riser, which cuts off the enricher circuit as it warms up. It should take under 5 minutes.
how do these chokes know when to shut off/turn on? is there a temp sensor in the choke mech.?
As the choke heats up it causes an internal wax pellet to melt, expand, and push forward a plunger that seals an opening inside the carb. The choke gets it heat from the residual heat of the engine, ambient air temperature, and from an internal electric heating coil which is energized only when the engine is running. The majority of the heat comes from the electric heater so the function is mostly time based with partial effect coming from the other heat sources. The auto choke on many bikes are connected in series with a power resistor before reaching electrical ground. Selecting different resistance values of the resistor allows the individual manufacturer to tailor the speed at which the choke lifts off but most are typically around 10 to 14 ohms.
Had a big swap meet at the shop today so I couldn't spend any time using this great information. I did however just fire the scoot up from cold for reference. It started immediately and ran exactly like it should for about 20 seconds, either idling or throttle blipping and after that time just bogged out and died qucikly. This sounds too quick to be a choke issue, no? I will run those tests and look into the valves but any other thoughts?
again I'm used to the really old stuff where voodoo and witchcraft isn't involved!!
I know you said it's getting fuel, but are you positive it's getting enough fuel? 30 seconds seems a little long to be a float issue, sounds more thermal, like valves or ignition. Does it start right back up after it stalls, or does it take a minute? Do you have any way to tell if it has spark when it quits?
It does take a minute to start again after stalling. but when fully cold it starts right up which has me thinking along the valve train of thought. no time to look at til tuesday. I'll keep you posted.
It doesn't "got" to be. It is thermal. It could be a tight valve, but it also could be any ignition component such as the coil or CDI. As with any such issues with these scooters, the valve lash should be done first since it's just so d@mn common.
Post by Eat Sleep Scooters on Nov 1, 2010 13:03:19 GMT -5
From my experiences, and I could be wrong, the thermal thing has always been valves for me. A coil will get hot and then croak completely and never work again. I have seen that a few times but never have I seen a coil "half work." CDI's either work or they dont. But like I said, I could be wrong.
Post by scootercapecod on Nov 1, 2010 15:43:15 GMT -5
I haven't noticed anyone mentioning an air/fuel mixture adjustment. It wouldn't hurt to try this test: Once you get it started and it's running, try putting your hand over the air boxes intake hose. Lightly at first and firmer as you go. If the motor picks up speed with a light airflow restriction you know you're a bit lean, if it just bogs down and dies it's too rich.
2011 Peace sports 150 TPGS 804 NO rev CDI slightly modded stock exhaust, modded stock air filter.
I have not checked that spark thing (lazy ;-) before it shuts off is starts to bog down slightly and gradually, so for about 15-20 seconds its fine then it starts to not take any throttle and quickly bogs out. I'm digging in to this today though so I'll have more info soon!
I've got the air screw set stock and its the same as the old carb so I don't think its an air mix thing causing it but you never know. will check all that out.
wereed: HOw can I start a thread?
Jun 1, 2013 10:55:49 GMT -5
wereed: or respond to a thread I started three years ago...
Jun 1, 2013 10:56:07 GMT -5
marklorenzi: I just bought one of the Fleetwoods. They look like a clone of the Honda XRM's they sell overseas. It is in transit now and I should get it this week. I will try to post my experience here. Call me the guinea pig hahaha.
Jun 2, 2013 20:29:11 GMT -5
flyangler: wereed, this forum is read only the new forum is on the banner above. Dan
Jun 5, 2013 7:35:29 GMT -5
silkyg1973: can someone please tell me how to post
Jun 10, 2013 12:08:46 GMT -5