Hard starting, and Wont Idle **SOLVED**

I wanted to make a new thread with the current issuses, and things that have been done so far.

Things that have been done:

carbs cleaned
floats wet set
enrichment passages cleaned (sprayed carb cleaner and shot out of end)
all jets clear
bench sync done
valve clearances checked
new throttle shaft seals
new air filter
new battery

Current Problems:

The bike is still very hard to start. It will crank strong and pop here and there. Then after a while it will get going. Once it gets going I can keep it running if the rpms are 2k or higher. If I let the rpms drop it dies.

After a while of this I can eventually let the rpms come down to 1100 and it will idle on its own. But not until it is good and hot. Then after this I can shut it down and restart no problem.

The initial start and warm up are where the problems lie.

 

Re: Hard starting, and Wont Idle

Did you do a running vac sync?
How many turns out are the idle mixture screws?
Your carbs are out of sync , idle mixture too lean.

 

Re: Hard starting, and Wont Idle

+1 on the lean idle... check that first... What color are your plugs? Airbox or Pods? stock or aftermarket exhaust? Try turning in your idle adjustment screw a bit too...

When you cleaned your enrichment circuit, was carb cleaner shooting out... harder than from the can?

Also, is your choke cable binding and otherwise operating properly? Is the gas old?

I had a similar problem, and it was a bit of all of these...

 

Re: Hard starting, and Wont Idle

I havent done a vac sync yet. Would this help with the hard starting? The mix screws were 2.5 turns out. I brought them to 3.5 and briefly tried to start and it was being very difficult so I just gave up for the night.

The bike is all stock. Stock airbox and exhaust. The carb cleaner was shooting out of the metering ports. It wasnt a 10 ft stream, but it definitely shot out. I would say maybe a 5 ft stream.

Choke cable is working properly and gas is brand new.

So too richen up the idle I have to turn the mix screws in right? So should I maybe try 2 turns out?

 

Re: Hard starting, and Wont Idle

Turning the mixture screws in leans the idle, out richens it. 2 1/2 turns is a good starting point.
Start by doing a running carb sync, that should help. Improperly synced carbs will make hard starting engine.

 

Re: Hard starting, and Wont Idle

Ok I guess I will try a running sync.

This bike is becoming extremely frustrating. Hopefully this will accomplish something.

Thanks for all those who are helping so far.

 

Re: Hard starting, and Wont Idle

I have been thinking about something and hoped you guys could clarify this for me.

Is the enrichment circuit only used for starting, or does it also help the bike idle? I ask this because I am wondering what the enrichment circuit actually does after the bike is started.

Also does the pilot circuit have anything to do with starting, or is that just for idle? I am starting to wonder if when I was cleaning I enlarged the pilot jets. They were clogged pretty bad and I had to use a sewing needle to poke the stuff out.

I bet an enlarged pilot jet would cause poor idle, and very hard starts right?

 

Re: Hard starting, and Wont Idle

Well I thought I would give an update to this thread for anyone that may have the same problem.

I took the carbs back off the bike and starting taking them back apart. First thing I found was #2 bowl bone dry. The bloat was binding up and got stuck in the closed position. What I found was the pin was a little bent, and causing the float to bind. Next thing I found was one of the rubber O rings on the mix screws was cocked in the hole, and probably clogging that hole. I was pretty sure these things were causing the problems, but I decided while they were off again to rip them completely 100% apart.

So I took every single piece of these carbs apart, and soaked everything in carb cleaner overnight. The next day I blew every single passage out with 135 psi. This time I put the air nozzle in the air jets and I was able to feel a good blast of air from the main jet, pilot jet, and siphon tube in the bottom. I also got a good fitting carb cleaner tube to fit in the metering port in the bowl, and got a stream to shoot the advertised 10 ft from the bowl.

I put everything back together, and did a good bench sync using the method of comparing the butterflies to the holes in the top of the venturi. Then wet set all the floats so they were dead in the middle of the screws.

Got it all back together today and I could not believe how quick this bike fired up. Literally only cranked for a second and fired up. It now idles beautifully at 1000. I can even keep it less than that it runs fine.

So now on to fine tuning and running sync.

 

Do you have a link to the instructions for wet setting the floats? I can't do the clear tube method since the drain screws on my carbs are stripped.

 

Gotta get those out to do the wet set...

This might help
http://www.xjbikes.com/Forums/viewtopic/t=4281.html


Glad to hear you solved the problem jf2006

 

http://www.xj4ever.com/setting%20fuel%20levels.pdf