something clever designed to make people look at this thread

[sonof_perdition]

I have an 06 honda 400ex... fmf powecore4.. K&N filter with an outerwear and running with the airbox lid off.. rejetted according to fmf jet kit specifications for said mods at sea level.

1) starts fine.. no problem apart from the typical cold blooded honda starts. it will idle. i thumb the throttle real quick after about a 2-5 min warmup and it will bog out and nearly die but if i ease into it it will rev up and sound great. Would you recon I should go up on my jet size?

2) Ok this has never happened before...i run my quad out of gas after every trip so as to not let gas sit in the carb...that being said ran my quad all morning at florence.. ran great! got back to camp... topped off the tank for the next ride.. started great... got onto the sand and it fell on its face... no power and wouldnt start... pull started it and it ran rough and eventually lost power and died... pulled it back to camp... switched plugs and it started.. ran it back to the sand and it did the same as before... towed it back to camp. went to town looking for parts ( was thinking possibly starter solenoid or my cdi)... no one had parts i thought I needed... came back to camp and started it up. ran great the rest of the trip without an issue... wtf? clogged jet and if so should i tear into the carb? piss poor operator? :)

any ideas or help is greatly appreciated

[honda400ex2003]

for the 1st question- what are you at now?

I would say that you probably had something clogged up in the main jet causing the issue that would have it die once you got on it. i would at least take a look at the carb and make sure it is cleaned out good. if it stays running fine that would probably be my guess.

steve

[tri5ron]

first try a double-dose of Seafoam, and see if that fixes it.
if not, check the screen in the petcock to see if it, or the fuel lines have any gunk in them.

You might also want to double check the fuel line for cracks, the rubber intake boot for any cracks, or if the carb clamp is loose.

Report back with your findings.

btw, how's the charge on your battery, and are the terminals clean and tight ?

[sonof_perdition]

I haven't torn the carb apart to inspect for clogged jets yet but running a fmf needle on groove 3...170 main... stock pilot...fuel screw turned 3.5 times...

[honda400ex2003]

sounds pretty close except that the 170 is a bit much on a stock engine with just a system. is the fmf stuff the same style as the dj stuff? I think it is but cant remember. i think it is just a rebadged DJ kit with fmf stuff on the box. Same with the moose one. steve

[sonof_perdition]

yes it is just DJ re badged with FMF... was looking at their instructions and I installed according to their specs or rather their recommendations... but I put a .165 in my wifes 400 with similar mods (except she runs a DRD slipon) and hers seems to run fine as well.. cant remember if she has the throttle issue or not... gotta go buy some gas to run some tests... drained the tanks after my trip and put it in my car..

Rich

[honda400ex2003]

those mains just seem so freaking big... that is a 190 equivalent on a stock engine. they do get richer as they get hotter, maybe that is the symptom you were feeling, super richness once it gets on the main jet. it would def feel like it is clogged up when it really rich like that. just out of curiosity, how does your plug look? im not saying this is the issue but is one of the most likely suspects from a diagnosis standpoint. if it did it consistently when warmed up it was either clogged or really rich.


hard to say, steve

[sonof_perdition]

Im no mechanic and have limited experience with engines but from what i've read and from pictures I have seen the plug looks to be right where it needs or should be... Over all it runs strong except for the quick throttle ups at idle after having warmed up (I know better than to wrap it up cold) with maybe a slight rich smell in the exhaust... mostly was concerned about it dieing on the sand... though maybe bad gas or clogged jet or fouled plug... dont know though...

Really appreciate you helping me trouble shoot though... gonna try to tear into the carb tonight or tomorrow... frightening thought for me lol

Rich

[honda400ex2003]

check out the carb first and see how it looks that will be the first step.

the trouble i am having is that you are giving all of the signs of a rich engine... i can only go off of what you give me though.

Even in this last post you said that it when warmed up it bogs out which to me would imply that the main is rich enough not to run good. anything can run well while warming up, testing it under a good load such as sand is when the engine gets warmest and will run the richest. All of the attributes of sand are there with more heat there too. that also makes an engine run richer. I bet if you put a 152 fmf main in there it would be a totally different animal. may seem small but i would bet that your plug will look good from the needle and the pilot circuit no matter what since they are super close to where they need to be. Is the plug black most of the time?

just my .02 though and an idea of where i am coming from on the subject. Lets see how the carb comes out first.

steve