replaced timing chain.Backfire only w/ Choke Off

[sleepin400]

I just completed the timing chain install. Everything seemed to go fairly well. Everything seems tight and lined up. Rotate the engine and no binding.


Fired it up and it runs decent. Untill.... I start to turn choke off. The SECOND i start to move it off choke it starts to sound different (hear more sucking and just starts to bog) Then it take more to keep it running and it will back fire. Choke back on full and it smooths out again.


Any Ideas?

could anything be lined up wrong, or think its in the carb.

thanks for the help

[dalejiw25]

Refer to this thread:
http://www.exriders.com/vbb/showthread.php?threadid=445884

[Scro]

So all you did was replace the timing chain? Was the carb or exhaust touched since it ran smooth before the timing chain install? If they weren't touched, then I would suggest going back and double checking your timing.

[sleepin400]

well, I've been known to give way too much information in my past on just about every subject. And from my observation the more I try to inform people about my issues/situation the less response I get. I do agree with lots of info but I tend to talk to much. And the detailed sig is a good idea I didn't realize mine was so brief, I'll try to update that.

I have a 2001 400 ex with a 11:1 piston, Stage II Cam, Header, exhaust, ported head. Jets I can't remember right now its been a while I'm trying to get my bike running again and get 4 wheeling back into my life.

On to the problem:

Again I'm sorry I meant to say INTAKE backfire.

as for the update: My friend suggested timing to me as you did so I worked on it tonight and moved a link on the cam chain and tried it out. It seemed to MAYBE be off just a bit so that might of been the problem. I re-did the vavle lash but ticks pretty loud. I didn't let it run but a few seconds. So I don't know if my intake backfire is still there. I'm taking it to a friend this week and have him take a look at it.

I do appreciate you who have and do chime in to help out. Even though I and many do not say how much some people help on here and forums alike. You do help people out. And I have been bailed out many times from people giving a hand over the computer from a different state some times country. I'll be the first selfish one to say I haven't helped as much as I have been helped. So for all who do there selfless assistance to us with mutual hobbies I send a thanks.

[hocman123]

just to make sure u know how to set the timing on the machine right

the engine has to be at top died center u have to put the cam in with the loobs facing up and line the 2 lines on the sprocket up with the top of the valves and u should be perfect

o and if u have a hot cam u need to make ur intake valves .005 and ur exhaust side .006 a little defferant then stock #

[sleepin400]

thanks for the brief install description. Everything was what I was told except. cam lobes down. So no valves will be open. The link I was given on my other post about timing chain install was a hotcams install page and it had lobes down. This is a big difference. Anyone else verify? TDC and lobes up? this will load the springs when you put the cover back on.

thanks

[honda400ex2003]

tdc and lobes down. you dont want your valves open at tdc. steve

[hocman123]

yea sorry i said that 2 times last night i think it is b/c i just did a lot of work on car cams and they dodn't have rockers so i got a little confused sorry