Engine Dies at 1/2 throttle turn and above

19 replies to this topic
  • DRZ400_rider

Posted July 29, 2007 - 01:11 PM


Here is my setup:

2001 S model reborn


Just installed the Hot Cams and now bike rips up to when I get to >= 1/2 Throttle, my engine dies . I must press the starter button to get the engine going again. Here is how I am jetted:

I ride 0~1000ft above sea level

JD Jetting Kit (thanks TT)
162 Main
52 pilot
Blue Needle, clip on 3rd groove
2 1/2 turns on fuel screw

Anyone have any ideas? I have a feeling it is jetting related.

  • Eddie Sisneros

Posted July 29, 2007 - 01:14 PM


main jet laying in float bowl.

  • DRZ400_rider

Posted July 30, 2007 - 03:24 PM


Sorry Eddie, forgive my lack of full comprehension....:bonk:

Are you saying that my floats are stuck and I possibly just need to give my carb a nice cleaning?? :excuseme:

I have read that often people must go leaner after adding the Hot Cams.

Thanks for getting back to me :worthy:

  • William1

Posted July 30, 2007 - 03:30 PM


He said maybe the main jet was not tightened, and vibrated out and is now simply sitting in the bottom of the float bowl.

  • Eddie Sisneros

Posted July 30, 2007 - 03:45 PM


i cant see how what i typed could have been understood any other way.

  • Jim Hale

Posted July 30, 2007 - 03:45 PM


Makes sense... always wondered what would happen if the jets came off.... good to know it doesn't explode :smirk:

  • DRZ400_rider

Posted July 30, 2007 - 03:48 PM


Yeah thats kinda what I thought he meant, and I really really wish it was that simple.

However, negative the main jet was on tight when I removed it.

Either way is it related to my main jet and the engine not getting fuel, rather than it being too rich I am gathering? I can look and see if the jet is clogged...

Any other suggestions? Believe me I exhausted my searching skills before adding to the pile of questions that seem to be repeated throughout time :busted:

I really appreciate anyone taking the time to give me some ideas :ride:

  • DRZ400_rider

Posted July 30, 2007 - 03:50 PM


Sorry Eddie, thought that you were talking slang...

Guess I didn't think that the main jet coming off and literally laying in the float bowl was possible, but then again, I guess anything is possible

  • Eddie Sisneros

Posted July 30, 2007 - 03:50 PM


so you cannot accelerate past 1/2 throttle at all?

  • DRZ400_rider

Posted July 30, 2007 - 04:20 PM


Yes I can get up to speed, but once I get ON the throttle, every time, consistently it (my engine) will die and the only thing I can do is, restart my engine, flogging the throttle doesn't do anything. As long as I don't go past 1/2 throttle, I am fine

but what the hell fun is that :devil:

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  • Eddie Sisneros

Posted July 30, 2007 - 04:59 PM


this happens while opening the throttle quickly?

if you roll the throttle on slowly it wont take wot?

  • DRZ400_rider

Posted July 30, 2007 - 05:07 PM


Its appears to not matter much either way, whether I roll it on fast or slow. I would say that it seems to happen more when I roll it on fast and get up to speed.

  • Eddie Sisneros

Posted July 30, 2007 - 05:12 PM


but no matter what you do it will not take more than 1/2 throttle?

wont pull to the rev limiter?

  • DRZ400_rider

Posted July 31, 2007 - 07:13 PM


No, it definitely won't rev to the rev limiter. It will go past 1/2 if I roll on slow, but soon after the engine dies. So i have gotten the revs up, but not near the limits of the big gun over rev

  • William1

Posted July 31, 2007 - 07:18 PM


Did you try your old CDI?

  • Eddie Sisneros

Posted August 01, 2007 - 03:59 AM


i agree,put your stock cdi back on for a test.

  • tawheed

Posted August 01, 2007 - 01:45 PM


i had a very similar problem and it was caused by the aftermarket cdi.. absolute trash

  • Eddie Sisneros

Posted August 01, 2007 - 03:46 PM


pro-comm = junk

  • DRZ400_rider

Posted August 02, 2007 - 06:56 AM


Thanks Eddie, I will try it out. While I have the carb apart, how does my jetting look? I was thinking to drop down to a 160Main and slightly leaner piolet...

  • kman780

Posted August 02, 2007 - 07:55 AM


Thanks Eddie, I will try it out. While I have the carb apart, how does my jetting look? I was thinking to drop down to a 160Main and slightly leaner piolet...

Before doing anything to the jetting you might want to try the old CDI, that way you are only working with 1 variable at a time.

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