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Discussion Starter · #1 ·
I know there's hundreds of threads for jetting so I might as well make another. 2005 400ex no engine work buying a lexx slip on stock headers [email protected] filter with outerwear protector and no airbox lid. I read that 170 dynojet would work and thats the highest I have. Also going to be throwing in a 42 pilot. Im around 1000 altitude.
 

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It adjust's the Mid Range throttle.

Pilot Jet = Effects the Idle
Needle = Effects Mid Throttle
Main Jet = Effects the Wide Opened Throttle

Some Carb's like FCR's and Flat and some other Flat Slide styles Have what is called a Starter jet Effects the First Initial Start u Prime.
 

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Discussion Starter · #6 ·
Alright got the exhaust on today and tried a 160 main first. Bogged really bad on acceleration so I put a 170 in and it doesn't really bog anymore, sometimes a little but it's alot better. But now I feel like the engine is running a little hot, maybe I'm just paranoid. Couldn't find my spark plug socket so I couldn't check that. Also if any of you are running a uni filter how the hell do you keep it on? Mine has been falling offf left and right.
 

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So now that you Got the Engine to run a little better "notTo Bog Nearly As bad" leave the 170 In try just Moving the Needle Clip Down a Notch to Rich'n up the Mid Range.

For the Air Filter:
It should have come with a Mesh Looking Insert inside of it to keep it from Collapsing and Falling off.
 

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Discussion Starter · #9 ·
If the 170 is too big is it possible that my engine will run hot? And the only thing that came with it was the filter. Doesn't seem to fit well i dont know why nobody else has problems that ive seen anyway.
 

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For the Filter:
I just realized you said you have a K&N... I was thinking it was a Uni for some reason. Sounds to me like you Might be missing Hard Internal Ring that is supposed to come with those Filters "So the Filter Hose Clamp has to Tighten down onto" Other why's I think what is happening is no matter how tight you tighten it you're just making it slip out of the Rubber. I know the OEM Filters have an Internal Mesh piece that has 2 Purposes.... 1 keeps the Filter from Collapsing 2 gives the Hose Clamp something to Clamp down onto... I Would try Cutting the Piece off the old Internal Mesh Part that inserts into where the Filter Clamps on to so the Hose Clamp has something Sturdy to Squeeze down onto. Here is the Part Number *17211-HN1-000 BODY, AIR CLEANER* to the Piece I'm talking about... "You Should Have the OEM Filter and Internal Mesh Piece I would Think"

I honestly would Suggest Messing with the Needle now. If it's Still running HOT with a 170 Then your Mid Range Needle needs to be Richen'd up. If you have never moved it before more then Likely it's still on the Factory "Stock" Clip Setting and needs more fuel. These Engines will Run pretty hot. As long as the Head pipe isn't Glowing Bright Red hot at Night Time while riding it should be fine. Now if it Glows a Little bit Red Hot while idling "At Night" it's fine. Just do not wanna see the Entire head pipe glow or "Super Red Hot" Slight Glow will be normal.
 

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Discussion Starter · #11 ·
Alright did some more testing today and figured a little more out. I've never messed with a needle jet before so it was new to me. I'm not sure if I even found it but I was getting pretty mad so I said screw it after awhile. First I took the top of the carb off because that's where I thought it would be. (Top of the carb when it's on the bike, 3 screws, a triangle looking plate) couldn't see anything that resembled a needle in there so put it back together. Then I took the bowl off and took my main jets out and found the needle. Took the triangle plate back off so I could get the needle out. Got the needle out and there was no "notches" on it that I keep hearing about. Looked at my dynojet needle that's still in the package and there's about 5 notches on it. I put that one in and the clip closer to the end of the needle (the needle would be farther out on my main jet side) put it back on the bike and it ran pretty bad. Idled very abnormally and bogged alot. So I took it all back apart and put the stock needle back in everything the same. Went for a little ride and got it up into the higher rpms. Seems to be running good alot of noticeable power increase in 4th and 5th gear but the throttle definitely hesitates. I can pin it in 4th and 5th and it slowly gains rpms. If you have any suggestions on the needle adjust that would be awesome. I'm pretty sure if I get that needle on the middle notch it will run mint. (Hopefully)

Oh and I do have a uni filter, just got it a few days ago. It just doesn't seem like it fits very well. My old k&n went inside (I think) the intake, but the uni goes inside and on the outside. I just can't get it to fit like it should.
 

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Discussion Starter · #12 ·
Did some more reading and found out that I was right when it came to the needle. But now all I need to know is where to put the clip. Do I want it closer to the bottom of the needle (not sharp side) or the side closer to the main jets. When I tried putting the dynojet needle in I had the clip 1 notch closer to the flat side of the needle, and it ran like crap.
 

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Discussion Starter · #14 ·
Alright so tomorrow i will try to lower the clip. This is kinda confusing me because some of the lexx exhaust posts that ive read people are running like 155 main jets around the same altitude as me. But my 170 seems to be working alright so I dont know what to think haha. All I know is that the power is alot better than before.
 

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Discussion Starter · #15 ·
This thing is really getting on my nerves haha. Went out today and started messing with the needle. First screw I took out of the triangle plate fell into the engine and lost it. Had too look around for half an hour and finally found one off a 3 wheeler carb. So I moved my needle clip lower, farther towards my main jet (4th notch, dynojet needle). Ran like crab bogs way worse than having on the middle (3rd) notch. So then i decided to put a 165 main in and put the needle on the 2nd notch. Ran the best it has but still is not great. Bogs sometimes and very odd throttle response. I finally bought sparkplug socket so I will try that tomorrow and hopefully will give me something to go off. One thing I dont understand is how it would run (decent) with a 170 main in and almost run the same with a 165. All I know is every time I put the needle clip closer to the main jet (richer) it always runs alot worse. There was also a small washer that came in the same bag as the dynojet clip and im not sure where it goes on the needle, maybe that could be part of the problem?
 

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165 & 170 main jets are almost the same - I always went up two sizes at a time till it ran like the choke was on then backed it down one size at a time till it ran the way I wanted it to.

I never changed a pilot jet, slide needle (that wasn't damaged) and I only changed the needle clip position when it ran like crap at half throttle steady speed.

Sounds like you are getting there - try a 155 main jet
 

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Discussion Starter · #17 ·
Finally got it tuned and running good. Big thanks to you guys. Final setting are a 155 main jet, 42 pilot, needle clip second from the top (2nd farthest from the main jet), never touched the air/fuel screw. Kept my airbox lid on didn't feel like messing with it. Next upgrade will probably be a stage 1 hotcam but I'm not exactly sure yet, not sure if it is worth the money.
 
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