northwest Texas
01-21-2006, 08:39 AM
Hi guys, I just subscribed after having been an off and on viewer of the forums.
Anyway, my brother in law bought a DVX 400 several months ago (it was a demo) and after a couple of hours of riding it will foul the plug I guess (it doesn't look too bad) because once you replace it, the engine will go back to running right. The symptoms are it doesn't run quite as crisp I believe and then it just won't start. New plug and she's fine.
Anyway, he decided to install a full Yoshi exhaust. Initially it wouldn't start at all and finally it got to the point where it would. I think we changed the plug but I don't remember for sure. We couldn't get it to run more than a minute and that was it. It would take a new plug to fire back up after several times of that.
So anyway, he's got it running now but it's still not right. It hesistates and stumbles I believe although I've only heard him riding it once since he's got it running. It seems like most of the problem begins near half throttle and gets worse.
Here's the particulars. To begin with, we checked all of the jets and such in the very beginning. All were stock #'s, 130 main, I forget the other #'s but they all corresponded to stock sizes.
He has installed a Dyno jet kit. A DJ needle has replaced the stock. I believe the clip is in the next to top position making the needle low in the carb. I think he has a DJ main jet #120 although he has had the stock #130 in there initially when he put the pipe on. We kept going down in size (main jet) until we could get it to run which explains the small size.
I don't know if it's getting too much fuel or what, it acts like that is the issue. My weak spot is the carbs.
As for the other particulars, the elevation ranges around the 3-4,000 foot range.
I can't think of anything else right now and I figured the more I talked, it might eliminate some questions
Anyway, my brother in law bought a DVX 400 several months ago (it was a demo) and after a couple of hours of riding it will foul the plug I guess (it doesn't look too bad) because once you replace it, the engine will go back to running right. The symptoms are it doesn't run quite as crisp I believe and then it just won't start. New plug and she's fine.
Anyway, he decided to install a full Yoshi exhaust. Initially it wouldn't start at all and finally it got to the point where it would. I think we changed the plug but I don't remember for sure. We couldn't get it to run more than a minute and that was it. It would take a new plug to fire back up after several times of that.
So anyway, he's got it running now but it's still not right. It hesistates and stumbles I believe although I've only heard him riding it once since he's got it running. It seems like most of the problem begins near half throttle and gets worse.
Here's the particulars. To begin with, we checked all of the jets and such in the very beginning. All were stock #'s, 130 main, I forget the other #'s but they all corresponded to stock sizes.
He has installed a Dyno jet kit. A DJ needle has replaced the stock. I believe the clip is in the next to top position making the needle low in the carb. I think he has a DJ main jet #120 although he has had the stock #130 in there initially when he put the pipe on. We kept going down in size (main jet) until we could get it to run which explains the small size.
I don't know if it's getting too much fuel or what, it acts like that is the issue. My weak spot is the carbs.
As for the other particulars, the elevation ranges around the 3-4,000 foot range.
I can't think of anything else right now and I figured the more I talked, it might eliminate some questions