Kawasaki ATV Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter #1
Hey guys I'm new to the site I'm looking for some help I have a 2004 kfx 700 I got on a trade deal needless to say the "broke" throttle cable concealed the fact the thing runs like crap.. So from what I can gather I have a stock sealed air cleaner with a k&n filter, dual pro circuit exhaust, stage two performance rev box,looks like the carbs are set up with a #40 low speed in both carbs and a 120 main jet in front and a 124 main in the back carb.. I'm from New York and 95% shur I'm 1300-1500 feet above sea level. What jets should I be running?. 120/124 seems wrong but I don't know. Any input would be greatly appreciated. Thanx!!
 

·
Registered
Joined
·
718 Posts

·
Registered
Joined
·
15 Posts
Discussion Starter #3
I'm just looking to get the thing running right. As of right now the thing can't can't out its own way may as well walk you'll get there sooner.. Someone has been into the carbs and unfortunately didn't know a damn thing about what they where doin.. I'm just trying to see if there is someone out there with about the same set up I would like to know what they are running for front and rear jets
 

·
Registered
Joined
·
1,658 Posts
That exhaust was on mine when I bought it and it had IIRC 160/165 jets I would try around there. Only use keihin jets. These carbs have issues with the dyno jets
 

·
Registered
Joined
·
15 Posts
Discussion Starter #5
Seems how it has 120/124 jets in it now should I get different needles too?. I have no clue of the brand of jets or needles I just know the needle is definetly aftermarket it has a real small point on it compared to a stock one..
 

·
Registered
Joined
·
1,526 Posts
The dyno jet needles do in fact alter the jet size needed. Also dj jets always have lower numbers than oem jets. You will need to get factory needles to make jetting much easier.
 

·
Registered
Joined
·
1,526 Posts
I would make sure the valves are adjusted correctly. It seems to me that it was jetted when the mods were performed so that might not be the issue. The carbs could also need a good cleaning.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #11
Way ahead of ya on the cleaning that's where I ran into all of this. Someone was a dumbass putting the carbs together the last time. I've found pieces missing/backwards/and plain messed up on top of the fact it's not even close to jetted for this area that I live in.the air adjustment screws where like 6 turns out it's a mess.lol
 

·
Registered
Joined
·
15 Posts
Discussion Starter #13
I don't know about the internals of the engine it seemed to run great from idle to about 1/4 throttle then it would just fall on its face after that. But it's been about 20 degrees here in new york.even though I let it warm up it still falls flat.. That's why I think the jetting is off I wanna be able to run almost year around.. The guy I got it from claimes it only does it in the cold and runs great when it's 40 degrees and up.but he's lied about a lot of stuff so i don't know. I'm just trying to see if I can fix it somewhat cheap so I know I ain't in a hole with this thing
 

·
Registered
Joined
·
42 Posts
At the risk of being redundant... if it were me, I would probably get some stock needles and Keihin jets. See the chart below for some comparison as to where you are at with the DynoJets.

Dynojet / Keihin
122 / 135 Stock Front
124 / 138
126 / 140 Stock Rear
128 / 142
132 / 145
134 / 148
136 / 150
138 / 152
142 / 155
144 / 158
146 / 160
148 / 162

Someone else mentioned 160/165 front/rear if all you have is an exhaust. That will be close enough to know if it runs good. With it being so cold, if anything it would need to run even richer than the 160/165. If you have more than just exhaust it needs even more jet.

To me it sounds like you are way lean on the main jets with it falling off at large throttle input, and the DynoJet numbers you posted are almost stock! The needles in it might need to be shimmed/adjusted, but why mess around... just get the right stuff since it's not that expensive.

I plan on starting at 178/180ish with exhaust, 12-hole and Twin-Air (air filter) to start.

-=Mike G.​
 

·
Registered
Joined
·
15 Posts
Discussion Starter #15
All that I know for upgrades was the dual exhaust, k&n air filter,and there is some kind of stage 2 performance rev/cdi box on it and the clutch was upgraded..but thanks Mikey that chart did help me understand a little more about the jets.
 

·
Registered
Joined
·
42 Posts
You know.. just thinking about it, you could just buy some larger DynoJets and throw em in for kicks. If it didn't change the way it ran at all, it could be a fuel delivery issue... filter, pump, clogged line, etc.

Valve adjustment is pretty easy too, but if it idles when hot and restarts hot... meh.. lol I don't think valves just make it fall flat all of the sudden depending on throttle position (anybody?)

Maybe don't listen to me... lol You'll end up chasing all kinds of stuff. At least it's mostly cheap/free to do.

-=Mike G.
 

·
Registered
Joined
·
15 Posts
Discussion Starter #17
I can say it ran great as far as starting and idle and really light cruiseing around as soon as ya go to open over 1/4 throttle it pops cracks and just about kills it lf ya try to hold it. I'm assuming just the air adjustment screws being messed up was a big problem one was like 4 turns out and missing the washer and o ring. The other was like 6 turns out and was jb welded (chiseled off to find what appeared to be no problem with it).. The needles are missing the little washers that go on to the clips to hold them tight in place with the plastic retainer in the slide which where backwards and putting a lot o pressure on the springs. Honestly maybe the jets that are in it are fine I don't know I gotta wait till the mixture screws come in this weekend and maybe I'll try the 120/124 jet setup
 

·
Registered
Joined
·
2,369 Posts
I can say it ran great as far as starting and idle and really light cruiseing around as soon as ya go to open over 1/4 throttle it pops cracks and just about kills it lf ya try to hold it. I'm assuming just the air adjustment screws being messed up was a big problem one was like 4 turns out and missing the washer and o ring. The other was like 6 turns out and was jb welded (chiseled off to find what appeared to be no problem with it).. The needles are missing the little washers that go on to the clips to hold them tight in place with the plastic retainer in the slide which where backwards and putting a lot o pressure on the springs. Honestly maybe the jets that are in it are fine I don't know I gotta wait till the mixture screws come in this weekend and maybe I'll try the 120/124 jet setup
When it is running---Are the slides both opening properly and evenly on both sides----Also with the stock jet range you have now, if running correctly it would be exhaust backfiring for lack of fuel---Double and triple check the rubber diaphragms to be sure no cracks and both sealed properly.

Kenny
 

·
Registered
Joined
·
15 Posts
Discussion Starter #19
]

When it is running---Are the slides both opening properly and evenly on both sides----Also with the stock jet range you have now, if running correctly it would be exhaust backfiring for lack of fuel---Double and triple check the rubber diaphragms to be sure no cracks and both sealed properly.

Kenny


See that's where the problem lies is the carbs I'm assuming at the time I ran it the slides where not working properly someone put the little plastic spring retainers in the slides upside down so the springs where binding in the slides as for the diaphragms they seem to be fine I just got my new adjustment screws yesterday so I plan on putting it back together today. Hopefully all goes well and I don't run into any issues..
 

·
Registered
Joined
·
15 Posts
Discussion Starter #20
]

When it is running---Are the slides both opening properly and evenly on both sides----Also with the stock jet range you have now, if running correctly it would be exhaust backfiring for lack of fuel---Double and triple check the rubber diaphragms to be sure no cracks and both sealed properly.

Kenny


See that's where the problem lies is the carbs I'm assuming at the time I ran it the slides where not working properly someone put the little plastic spring retainers in the slides upside down so the springs where binding in the slides as for the diaphragms they seem to be fine I just got my new adjustment screws yesterday so I plan on putting it back together today. Hopefully all goes well and I don't run into any issues..
So to everyone that was following this I got all my parts for my 700 and put the old girl back together about 1pm with luckily no issues fired her up let it idle for about 15 minutes and took it out for a test. I pulled out of my driveway onto the road doin about 10 mph jabbed the old throttle and she stood straight up on me. So I've determined that I've fixed the issue.lol. Thanx for everyone's help!!
 
1 - 20 of 22 Posts
Top