Honda ATV Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
49 Posts
Discussion Starter · #1 ·
I have a 98 foreman trx400fw and it have a brand new top end and carb with a stage one jet kit and a snorkel with a factory air filter. The carb is adjusted to specs for the mods I have and the bike chokes when you give it gas. If you choke it it will run fine but idle high and I know your not supposed to do that. It smells like old 2 stroke fuel and smokes a little even tho the top end is brand new. I'm at a loss idk what else to do


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
1,756 Posts
Sounds like your jetting is off. You are lean on the pilot if it idles faster on choke. You are way off on the main and possibly the needle clip but I can't determine whether you are rich or lean. If you turn off the fuel and it revs better just as it runs out of gas then I'd guess it is rich on the main. If there is no difference then I'd guess you are lean on the main. The clip position is determined after you get close and start "fine tuning".
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #3 ·
It could be but its jetted specifically for my altitude and everything. Plus I can't find any jets at all for this carb except a dyno jet kit put together after you tell them your attitude and mods


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
1,038 Posts
It could be but its jetted specifically for my altitude and everything. Plus I can't find any jets at all for this carb except a dyno jet kit put together after you tell them your attitude and mods


Sent from my iPhone using Tapatalk


There are 3 circuits. Pilot (idle- 1/4 throttle) Mid (needle 1/4 -3/4 ) Main (WOT)

IF the later two run fine, you need to adjust your pilot jet & possibly your pilot screw...
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #5 ·
None of it works right lol I can't find anywhere to buy different jets to even try anything else


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
1,756 Posts
None of it works right lol I can't find anywhere to buy different jets to even try anything else


Sent from my iPhone using Tapatalk
I'd still guess jetting. Try to get your money back on the jet kit and buy a hand full of jets and start tuning. I'd go with stock on all plus several larger mains and perhaps one larger pilot.
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #8 ·
I'm less than 300 ft above SL. I can't find anything but main jets and stock rebuild kits anywhere.


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
5,956 Posts
Is it an OEM original carb with 100% original jets and all other parts original in it? Your carb boots in good shape with no cracks in them? Did you take the snorkel off and try it with the OEM carb all stock? You need very little (if any, and probably none) jetting changes with your setup, so something is wrong with your baseline stock config. My guess... its not stock.
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #12 ·
You may be right because I have changed the carb assuming that it would still be factory specs. I can take the jets out of the old carb and install them in the new carb?


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
5,956 Posts
Ya, check the float level while you are in there too. But if your new carb is not a genuine Honda carb of the same model# (is it an aftermarket carb? China?) then no, you'll have to reassemble your original Honda supplied carb to stock and use that.
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #14 ·
Ok I took the pilot jet the main jet and the emulsion tube out of the factory carb along with the needle. I reinstalled the factory washer above the c clip along with the extra washer supplied in my jet kit. The main jet out of the stock carb was much larger than the one in the jet kit for some reason anyways it fires up and idles easy and idles fine not choked and the bad fuel smell is pretty much gone. Now the only problem is I choked it back fires a little and won't take much throttle so I'm assuming I just need to play with the air fuel screw


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #15 ·
Well now nomatter where the air fuel screw is set it doesn the same thing... It won't take much throttle not choked...


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
5,956 Posts
I would put everything back in the original carb and run it... set it up stock, exactly like the service manual says... got no idea what sort of carb you bought (china knockoff?) or what it was meant to fit or whether stock Honda jetting parts will even work in it. Why did you replace the original carb?
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #17 ·
It is an oem carb and the original one was corroded inside cause the bike was abused


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
5,956 Posts
Is it a brand new OEM carb? Was it the exact Honda part number for your year and model application? If parts are different in each, then obviously it is not. No way to fix that... gotta have the correct carb set up perfectly stock.
 
1 - 19 of 19 Posts
Top