How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Louie Your Own Question
Louie, Technician
Category: Motorcycle
Satisfied Customers: 12305
Experience:  25+ yrs. experience
Type Your Motorcycle Question Here...
Louie is online now
A new question is answered every 9 seconds

I have a 1980 Honda Cm200t twinstar that i currently can not

Customer Question

I have a 1980 Honda Cm200t twinstar that i currently can not get to run. I had it running last week and yesterday i tried to start it and i cant get it to run. I have changed the oil, cleaned the carb and looked over the throttle cable. Here is a quick video of how it currently sounds with i am giving it throttle. ( ) if i do not give it throttle it dies right away or very soon after.
Submitted: 1 year ago.
Category: Motorcycle
Customer: replied 1 year ago.
is there supposed to be something attached to this brass piece ?
Expert:  kwiggins29059 replied 1 year ago.
The brass piece should have a clamp on it like in the picture below to hold the choke cable. Click here Scew 16 holds the piece that holds the choke. When you cleaned the carb was it completely disassembled and the jets and passages blown clean after soaking in solvent?
Customer: replied 1 year ago.
Okay thank you, ***** ***** look into that screw, yet will that effect anything? As i have tried to move that brass piece and it doesn't seem to move. And yes i did take apart the carb completely and soaked and make sure everything was blown through. Yet I did dissemble the carb again and the main jet seemed to be clogged again, so i repeated the same process.
Expert:  kwiggins29059 replied 1 year ago.
The brass piece is stationary. With what you describe about the jet clogging back up there may be a good bet of sediment/debris in the tank. What I would suggest is removing the tank and cleaning it. You can fill it partially with mineral spirits and drop in some small link chain (fishing the chain back out isn't usually a big deal) and shake it some to dislodge the debris. once it's been cleaned some install an inline fuel filter between the tank and carb fuel line. This will save from having to keep tearing down the carb and give you an idea of what's going on with the fuel flow and debris. Some other things to check are the point gap and valve lash as well as spraying some carb cleaner around the carb to head mount to see if there's any vacuum leaks. Check all that out and if it's still giving you grief just reply back and I'll do my best to help further.
Customer: replied 1 year ago.
Okay I cleaned out the gas tank, and the carb again and the bike now ideas. There is no response from the throttle though- the Rpms don't change when I twist the throttle
Expert:  kwiggins29059 replied 1 year ago.
Thanks, ***** ***** remove the airbox from the rear of the carb check to see that the slide is moving when the throttle is turned.
Customer: replied 1 year ago.
Okay I will look into that soon
Customer: replied 1 year ago.
I can't see the carb from the choke, if you can see from the picture the box is in the way, and if j could remove the box the tub would be in the way I think. However I can hear the throttle valve? Going up and down
Expert:  kwiggins29059 replied 1 year ago.
Thanks, ***** ***** can hear the slide moving then likely there's something clogging the jet the needle on the slide goes in or the passage under it. I'd pull it back down, soak it and blow the pasages with compressed air. This is very,very common. Most of the time if it's cheap enough and having the original carb only isn't an issue I recommend replacing the carb. The one for your bike is pretty affordable here
Customer: replied 1 year ago.
I took the carb off and when I twist the throttle I can see if go up and down, also when I hit the brakes- front of back the engine revs higher
Expert:  kwiggins29059 replied 1 year ago.
I'm at a loss on why it's reving when hitting the brakes. LEt me open this back up to other experts for you. Someone should be with you shortly.
Expert:  Louie replied 1 year ago.
Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, with "...throttle valve...go up and down...", is the needle moving up/down also?Still, it would still appear to be a fuel delivery issue. Proposed preliminary tries (if have not been done):• check the burn color of the spark plug's inner ceramic tip;- if black/sooty, then rich and/or vacuum leak issue @ the intake/after the carb;- if oily, then an internal engine problem;- if very light brown to whitish, then lean and/or an air leak concern @ air box/coupling/before the carb;• check the air box and air filter/element;- ensure tight/correct fit;- verify air entry is only through the designated opening;• check the battery voltage;- ~at least 12.7V when idling;- but not to exceed 14.5V ~ 15.0V when attempting to increase RPM.
Customer: replied 1 year ago.
The needle in the carb does go up and down when twisting the throttle, and the spark plugs are black and a little bit wet
Expert:  Louie replied 1 year ago.
I understand. Any guess on what the idle RPM is?And please re-check the carb including mounting/intake manifold + the O-rings and gasket.Of particular interest would be for the likely possibility of a vacuum leak at the manifold area.
Customer: replied 1 year ago.
Okay I will do that, how do I get to the gaskets?
Expert:  Louie replied 1 year ago.
Please click HERE for the exploded parts diagram of the intake manifold to the cylinder head. The gasket is # ***** while the O-rings are # ***** click HERE for the carb. Of interest/for checking would be item # *****

Related Motorcycle Questions