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Here are some of the upgrades that I just did to my KFX700.....Put new pro-circuit exhaust, K&N filter, Digital Performance Ignition, Dyno-Jet kit with 155 jets in the front and 160 in the rear and also hot cams. Also, I did the air box mod with the holes. I am still having some popping and it sounds like it is running lean. But, I am not a mechanic so I am not sure. Also, my valves chatter even though I set them to specs. Can any body give me any information or tips to help me out? It seems like no one knows anything about the KFX700's when I ask them. So, if any body out there knows anything about my upgrades, please help! Thank you!
Here are some of the upgrades that I just did to my KFX700.....Put new pro-circuit exhaust, K&N filter, Digital Performance Ignition, Dyno-Jet kit with 155 jets in the front and 160 in the rear and also hot cams. Also, I did the air box mod with the holes. I am still having some popping and it sounds like it is running lean. But, I am not a mechanic so I am not sure. Also, my valves chatter even though I set them to specs. Can any body give me any information or tips to help me out? It seems like no one knows anything about the KFX700's when I ask them. So, if any body out there knows anything about my upgrades, please help! Thank you!
The 155 jets seem to be a little rich for your setup. I originally bough my V second hand which had all of the same mods that you described (exactly) No problems at all. I originally had 135 jets in mine. Is is pooping in the exhaust or through the airbox? Pull a plug an read it.
Where is your e-clip in reference to the needle? Try replacing your ignition with the stock one and see if it repeats the issue. I have been told that the aftermarket ignitions are a waste. Mine has one, so I have nothing to compare to.
Thank you for replying. Reason I had the 155 and the 160 jets is because I started off with the 124 and 128 and it kept running out of power. So I called dyno jet and they said I need to go up in the jets and they sent me a number of jets and told me to keep going up in jets until I felt an increase of power. That is what I did. I read on this forum that some guy has a KFX700 with all the mods that I have but not the cams in it and he has 190 jets. It was the last post before I added this post. When I called dyno jet I asked them how to know if I have the jets right and they said that I needed to keep going up in jets until the popping stops.
Unfortunately, I'm no help at all, but whatever your solution ends up being, I hope you'll share it. I have a friend with a similiar problem with his Grizz.
The characteristics you describe sound "lean" to me and obviously Dyno is telling you to give it more fuel as well, but others say it needs less fuel? I REALLY want to find the solution to this. Are you only replacing the main jet? Perhaps bumping the pilot and the needle up will help
Well, there is a difference in jet sizes between Kehin and Dynojet. I will post a conversion on here later.
"Popping", BATTLEGUN, may be interpreted many different ways; I think it's fair to say that. I suppose the proper way would be to take out a spark plug and read it. That will tell us what the engine is really doing.
For clarification, I'm not a sparkplug expert but, in order to properly test a plug you must have a machine that is in good working order with a plug that is in good condition. I also think you have to have a controled operation for the best plug test. For example, you just did a quarter mile hill climb at full throttle such as a sand dune. However, I think you can probably get "some" insight as to what is going on if you don't test it with set conditions. I know a blackish, fouled plug = to rich and a whiteish melt looking plug = too lean. There are a lot of other colors and things to look for, but as I mentioned I'm not an expert and would like very much to learn more about this stuff.
I have replaced the front and back jets. Also I have set the needle on the next to the last setting. I am going to try to set it on the very last setting today and see if that helps any , but I though the needle settings were just for cruising speeds, not for if you were going full throttle.
The e-clip on the metering rod / needle should be close to center or just one notch down from center. This is where mine is now, and I have never moved it. This is the same concept as shimming the needle.
You said that you had the hot cams installed in your KFX700. After setting your valves where they are supposed to be, do you have problems with your valves chattering? I have 155 jets in the front and 160 in the back and my elclip on the back is one up from the last one. I did the air box mod by cutting the holes in the air box. I had to tape some of the holes back up because I thought it was letting it breath too much. What do you suggest I do to get rid of the popping and the valves popping? Thank you.
I have replaced the front and back jets. Also I have set the needle on the next to the last setting. I am going to try to set it on the very last setting today and see if that helps any , but I though the needle settings were just for cruising speeds, not for if you were going full throttle.
I was just trying to get an accurate picture of what you have done. I wasn't insuating that the needle was the culprit alone.
Again, not much help, but if you install aftermarket cams, would this affect the timing That could cause valve rattle right? Back to the carbs, you could always just invest in a bunch of jets and go and down until it acted right.
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