Hey All,

I have an '04 Z400, that has a Full Yoshi RS3 Exhaust, and a UNI Foam filter, with open air box.

When Starting the ATV Cold, with the choke on, I have to plug the exhaust in order to get it started.

If I don't It wont start, But the second I plug the exhaust it fires right up, then once warm, it starts no problems.

Is this normal? I am assuming this is happening because the Yoshi Exhaust is too free flowing, and plugging it gives the engine back pressure?

It's no that big of a deal, I just want to make sure that something isn't wrong.

Thanks,

-TheChad

 

Quick question, has the problem been there only since the exhaust was put on,or did it just start recently? If it started after the exhaust, you may be a bit lean on the pilot jet , but the choke should give you all the gas you need to start. Have you checked the valves lately? my son's 300ex was a pain to start cold, had to baby the throttle, set the choke just right, and keep feathering the throttle to get it to start, when warm, it started with a touch of the starter button. Turned out the intake valves were way tight,holding open just enough to lose compression. Set the valves to spec, and now it fires up in a couple of turns of the starter, and without the choke on. If everything else is set right, I would look to the valves as a problem.

 

I want to say It didn't do it when I first put the exhaust on, but not long after it started..

It doesn't get ALOT of use, so I would hope the valve's would be warn too much, but Is there an easy way to check them?

I think it's a little lean in the winter it backfires when cold. I'm not all that experienced with carb jetting, so I don't really know how to tell if the jetting is spot-on. I know I paid the Local Powersports dealer to rejet it when I got the exhaust, and they had it jetted way off, so I ended up rejetting it myself. It's been ahwile now, So I don't remember all the details...

-TheChad

 

Have you checked the plug lately?DJ155 seems to be really lean for what you have for aftermarket parts.

 

<div class="FTQUOTE"><begin quote>Originally posted by: AIRMOBILE101

Have you checked the plug lately?DJ155 seems to be really lean for what you have for aftermarket parts.</end quote></div>


I haven't checked the plug... As a matter of fact, I couldn't even figure out how to get to the plug last time I tried....

Any tips for me?

-TheChad