I am still having problems with my Big Red. I bought a brand new carb for it, set it, put it on and it still idles very high. I have to run the engine fully choked to keep the idle down. I ran it that way sitting in my driveway for about 25 min to circulate the new oil I put in and did more tinkering on the idle screw, but it did not solve the problem. While the engine was running, I turned the petcock off, and to my amazement, the engine still ran after 45 sec to a minute later. Then, while fully choked and the gas off, the idle climbed VERY high, so I hit the kill switch. What could be causing this problem?

The bike has not been ridden in at least 9 years, and I didn't replace the fuel filter or the air filter. Could these items be affecting the bike in that way? Could it be the recirculation breather tube? I'm totally bummed out and at a loss.....

Thank you for all responses.

Tony C.

 

There is only one way a gasoline engine can RPM..........you have an air leak somewhere. It will be up to you to find it.

Do you have the slide in wrong? Does the slide come all the way down? Is the carb boot cracked? Could be any one of these and many more.

Bottom line is, the only way an engine can gain RPM is to give it air. Find out where the air leak is and you will find your problem.

One more thing. Please don't use the choke to settle the RPM down. Your going to burnish the bore and wash out your rings.

 

The carb is brand new factory sealed, and the slide is in and operating properly. Would a crack in the intake manifold cause this problem? How about a bad head gasket? Please help me out......

Thank you,

Tony C.

 

Hey man, my friends 89 warrior just had the same problem,
carb was fine, everything seemed fine..
it had a crazy high idle, idle screw jetting and air mixture were fine,
and didnt seem to make any difference..

After a ride it returned to normal,
the next ride, the THROTTLE cable busted clean out of throttle, and
he had to ride home tugging on the cable by hand..

check your throttle cable, it could be shot!

 

<div class="FTQUOTE"><begin quote>Would a crack in the intake manifold cause this problem? </end quote></div>
Absolutely. Any place an engine can draw air.
Like kukerdan said, if your throttle cable is hanging the slide up it will draw air.
<div class="FTQUOTE"><begin quote>How about a bad head gasket? </end quote></div>
Nope.
<div class="FTQUOTE"><begin quote> Please help me out...... </end quote></div>
I'm trying too, but you have to do the work because I'm not there.
Remember this. An engine on gasoline can't RPM if it gets no air. You have an air leak somewhere.

To check if the cable is bad just disconect it from the carb and start the enine up with no cable connected.

Just because it's a brand new carb does not mean the slide is in correctly. You had to take the slide out of the carb to hook the T cable up. If you did not index the slide correctly on the pin it will hang up a bit and cause the problem you have.